rimfire Tuner / Harrell

[littlesister]

Littlepod
I think the reason you found your results with the Harrell's "a wash" is due to the design of the tuner. The benchrest rifle I had used a Hoen 4000+ tuner. The design had an outer chamber, just like a Harrell's with a 1" weight like Orkan used in his video. The inner being well behind the outer. The Holeshot is this design as are the PRX based tuners. The problem with the Harrell's I believe is, when set in the lower range, the inner ring is even with or protrudes past the outer which I believe negates the effect of the tuner design. Tony mentions that to use the EC correction for the outer ring, it needs to be at least 1/4" beyond the inner riing. The light Harrell's weight adds a 1" "bushing" to achieve what I believe is effective design. When i looked at Orkan's determination of 3.5553" behyond the muzzle, I believe he is tuning to the 7th harmonic. He is shooting a 26" barrel an Tony mentions that he finds the 9th is best in barrels 22-25". Just my thoughts with no scientific backing. I'd really appreciate anyone more knowledgeable and with maybe some experience with tuners to chime in and let me know if I'm way off base.
Oh well. I just saw a thread on the Ezell tuner. Apparently, he cuts his rimfire tuner inner tube to a barrel specific PRX and it looks like it protrudes past the outer shell. Looks like that blows holes in my theory. I guess the bottom line is, try some and see what works best for you which as soon as the weather starts to break I will try and spend less time typing and more time shooting.

Littlepod
I think the reason you found your results with the Harrell's "a wash" is due to the design of the tuner. The benchrest rifle I had used a Hoen 4000+ tuner. The design had an outer chamber, just like a Harrell's with a 1" weight like Orkan used in his video. The inner being well behind the outer. The Holeshot is this design as are the PRX based tuners. The problem with the Harrell's I believe is, when set in the lower range, the inner ring is even with or protrudes past the outer which I believe negates the effect of the tuner design. Tony mentions that to use the EC correction for the outer ring, it needs to be at least 1/4" beyond the inner riing. The light Harrell's weight adds a 1" "bushing" to achieve what I believe is effective design. When i looked at Orkan's determination of 3.5553" behyond the muzzle, I believe he is tuning to the 7th harmonic. He is shooting a 26" barrel an Tony mentions that he finds the 9th is best in barrels 22-25". Just my thoughts with no scientific backing. I'd really appreciate anyone more knowledgeable and with maybe some experience with tuners to chime in and let me know if I'm way off base.
Oh well. I just saw a thread on the Ezell tuner. Apparently, he cuts his rimfire tuner inner tube to a barrel specific PRX and it looks like it protrudes past the outer shell. Looks like that blows holes in my theory. I guess the bottom line is, try some and see what works best for you which as soon as the weather starts to break I will try and spend less time typing and more time shooting.

Littlepod
I think the reason you found your results with the Harrell's "a wash" is due to the design of the tuner. The benchrest rifle I had used a Hoen 4000+ tuner. The design had an outer chamber, just like a Harrell's with a 1" weight like Orkan used in his video. The inner being well behind the outer. The Holeshot is this design as are the PRX based tuners. The problem with the Harrell's I believe is, when set in the lower range, the inner ring is even with or protrudes past the outer which I believe negates the effect of the tuner design. Tony mentions that to use the EC correction for the outer ring, it needs to be at least 1/4" beyond the inner riing. The light Harrell's weight adds a 1" "bushing" to achieve what I believe is effective design. When i looked at Orkan's determination of 3.5553" behyond the muzzle, I believe he is tuning to the 7th harmonic. He is shooting a 26" barrel an Tony mentions that he finds the 9th is best in barrels 22-25". Just my thoughts with no scientific backing. I'd really appreciate anyone more knowledgeable and with maybe some experience with tuners to chime in and let me know if I'm way off base.
Oh well. I just saw a thread on the Ezell tuner. Apparently, he cuts his rimfire tuner inner tube to a barrel specific PRX and it looks like it protrudes past the outer shell. Looks like that blows holes in my theory. I guess the bottom line is, try some and see what works best for you which as soon as the weather starts to break I will try and spend less time typing and more time shooting.

 

[littlepod]

Okay, I got some time to actually do the real measurements for Purdy - https://www.rimfirecentral.com/forums/showthread.php?t=544427

Stuck a rod down my muzzle hitting my bolt, subtracted headspace etc...

Muzzle to Bolt	21.9375
Headspace (Assumed)	0.043
Barrel Length (Muzzle to Bolt - Headspace	21.8945
End Correction (Inner tuner diamter * .3)	0.1905
Quarter Wave = Barrel Length / 8	2.7368125
Acoustic Length = QW * 9	24.6313125
Physical Length = Acoustic Length - EC	24.4408125
Rod Length = Physical Length + Headspace	24.4838125

So I then taped a little piece of tape on my cleaning rod at the Rod Length measurement above.

So yeh I'm really close to the setting. I'll do some more in depth tuning from like setting 10-20. Right now my tuner is at 11 and I also found 13 to be really good.

 

[littlesister]

Okay, I got some time to actually do the real measurements for Purdy - https://www.rimfirecentral.com/forums/showthread.php?t=544427

Stuck a rod down my muzzle hitting my bolt, subtracted headspace etc...

Muzzle to Bolt	21.9375
Headspace (Assumed)	0.043
Barrel Length (Muzzle to Bolt - Headspace	21.8945
End Correction (Inner tuner diamter * .3)	0.1905
Quarter Wave = Barrel Length / 8	2.7368125
Acoustic Length = QW * 9	24.6313125
Physical Length = Acoustic Length - EC	24.4408125
Rod Length = Physical Length + Headspace	24.4838125

So I then taped a little piece of tape on my cleaning rod at the Rod Length measurement above.

View attachment 7842198

So yeh I'm really close to the setting. I'll do some more in depth tuning from like setting 10-20. Right now my tuner is at 11 and I also found 13 to be really good.

You're lucky if your final length fell within the range of a Harrels tuner using the 9th.. Harrels were never developed to work with the Purdy method. Actually the Purdy method wasn't even around when Harrels were first developed. I've tuned several barrels with Harrels then checked them against the Purdy measurements only to find that they were not the same. I did have one gun that the different methods did correspond . It was a Calfee built with a 23 inch .870 dia. barrel.. I know you can generally find more than one good tune with a Harrels but the true tune will always be repeatable. I also know Purdy says you can use a different Harmonic if your length doesn't fall within tuner range. Would this be the true tune? He does recommend the 9th. I'm still not convinced that the Purdy method gives you a true tune. Only my opinion based only on my experience.

 

[Arkansan]

Here is something to consider. The 2 tuners shown without inner tubes extending are both Purdy RX tuners, the JNL Chacon tuner on the rifle, the other is the is a CST SFP Pro X tuner. The Pro X has a 1" bushing for a 24" barrel, the JNL preset by Joe for a 20" Kidd Barrel. I have a 1/2" bushing to try on my 19.75" GM barrel. I believe the reason the Purdy prescription may not be working well is, I believe it is based on tuners with an inner tube some distance from the outer. Orkan's success with the Harrell's I think is due to his addition of a 1" extension which brings the design more in line with Tonys formula. The Harrell's set at low numbers does not allow the outer section to function. The outer tube subtracts the second EC in the equation. Just a thought. When I finally get around to being able to try these out, I may put the Harrel's on but, will probably wait until I have my 26" barrel finished and will use the light, 1" extension. Interestingly, I looked at info on the Ezell tuner which has a protruding inner tube and Mike indicates these are cut to lengths to correspond with Purdy RX for specific barrel lengths. As I mentioned before, when I checked the setting on my JNL tuner using the very precise calculations on the ProX website, the number was within 2 of what Joe had set for my 20" barrel and it works.

 

[littlesister]

Here is something to consider. The 2 tuners shown without inner tubes extending are both Purdy RX tuners, the JNL Chacon tuner on the rifle, the other is the is a CST SFP Pro X tuner. The Pro X has a 1" bushing for a 24" barrel, the JNL preset by Joe for a 20" Kidd Barrel. I have a 1/2" bushing to try on my 19.75" GM barrel. I believe the reason the Purdy prescription may not be working well is, I believe it is based on tuners with an inner tube some distance from the outer. Orkan's success with the Harrell's I think is due to his addition of a 1" extension which brings the design more in line with Tonys formula. The Harrell's set at low numbers does not allow the outer section to function. The outer tube subtracts the second EC in the equation. Just a thought. When I finally get around to being able to try these out, I may put the Harrel's on but, will probably wait until I have my 26" barrel finished and will use the light, 1" extension. Interestingly, I looked at info on the Ezell tuner which has a protruding inner tube and Mike indicates these are cut to lengths to correspond with Purdy RX for specific barrel lengths. As I mentioned before, when I checked the setting on my JNL tuner using the very precise calculations on the ProX website, the number was within 2 of what Joe had set for my 20" barrel and it works

I agree with your analysis. Bottom line. If you use a Harrels design tuner, the Purdy method may or may not work. You're better off going with a tuner designed for that tunning method.

 

[grauhanen]

Does Purdy ever say that Harrell tuners may or may not work with his "method"?

 

[littlesister]

Does Purdy ever say that Harrell tuners may or may not work with his "method"?

I've never known him to make such a statement. He even uses some of Harrels tube measurments for illustrations. When Purdy first developed his tunning method there weren't a lot of tuner options available. Harrels was pretty much it. It simply does not have enough linear adj. to tune some length barrels to the 9th. Now we have tuners designed for his tunning method. I could go on and on with tuners. I've spent hours and hours and countless rounds of Eley10x ammo playing with tuners. Just when I think I know what I'm doing, I find out I really don't. I guarantee you half the people on this website that think they have their barrels tuned. REALLY DON'T!

 

[littlepod]

I've never known him to make such a statement. He even uses some of Harrels tube measurments for illustrations. When Purdy first developed his tunning method there weren't a lot of tuner options available. Harrels was pretty much it. It simply does not have enough linear adj. to tune some length barrels to the 9th. Now we have tuners designed for his tunning method. I could go on and on with tuners. I've spent hours and hours and countless rounds of Eley10x ammo playing with tuners. Just when I think I know what I'm doing, I find out I really don't. I guarantee you half the people on this website that think they have their barrels tuned. REALLY DON'T!

Curious what your setup is. I went through the Hopewell method to find my tune since I bought a Holeshot. KSS recommended that the Hopewell method was the most easy to understand so that's what I did. I might pick up a Purdy tuner just for fun to compare.

Benchrest Rifle Stocks | Killough Shooting Sports

Enhance your shooting performance with the latest range of benchrest rifle stocks at Killough Shooting Sports. Same day dispatch on orders before 2 pm.

www.killoughshootingsports.com

It looks like with that one, the length is 2.474" tuner length for a 22" barrel, so I'd get the .5" extension.

 

[Arkansan]

This is the only picture I could find of the tuner that was on the benchrest rifle I had. What I remember from the muzzle end, it had no protruding inner tube like the Harrell's, much more like the ProX and JNL which are basically the same from what I can see.
To get some precise info on tuning these 2, I recommend going to http://cstmtech.com/sfp-prox-tuners. The number I got using the info provided gave me the same ( +-1) number that Joe set on the JNL tuner for my 20" barrel.
I have a 1" "bushing" for my 24" barrel, 1/2" for the 19.75. I don't know which was the first, CST introduced their tuner in 2014. Their page on the website is quite informative and the directions for tuner setup very precise i.e. for a 24" barrel, you use the 1" extension, which is for barrels 22.424" to 25.624", and use the formula 24-22.424=1.576/8=.197 which is the micrometer setting. The only problem with the ProX is, they only provide it in .75" so you need to get it machined to your barrel diameter, KSS will do that for you as will Joe.. I believe the setting formula for the ProX will work with the JNL.

 

[littlesister]

Curious what your setup is. I went through the Hopewell method to find my tune since I bought a Holeshot. KSS recommended that the Hopewell method was the most easy to understand so that's what I did. I might pick up a Purdy tuner just for fun to compare.

Benchrest Rifle Stocks | Killough Shooting Sports

Enhance your shooting performance with the latest range of benchrest rifle stocks at Killough Shooting Sports. Same day dispatch on orders before 2 pm.

www.killoughshootingsports.com

It looks like with that one, the length is 2.474" tuner length for a 22" barrel, so I'd get the .5" extension.

Curious what your setup is. I went through the Hopewell method to find my tune since I bought a Holeshot. KSS recommended that the Hopewell method was the most easy to understand so that's what I did. I might pick up a Purdy tuner just for fun to compare.

Benchrest Rifle Stocks | Killough Shooting Sports

Enhance your shooting performance with the latest range of benchrest rifle stocks at Killough Shooting Sports. Same day dispatch on orders before 2 pm.

www.killoughshootingsports.com

It looks like with that one, the length is 2.474" tuner length for a 22" barrel, so I'd get the .5" extension.

The gun that I'm currently competing with at 200yds is a Diorio V3 Turbo. Shilen ratchet, Bix trigger, Nightforce 12x55. Diorio tuner which is basically a modified Harrels. I shoot off a Pappas one piece and sometimes a Seb Neo. The barrel is weight tuned using my own tunning procedure which is a modified Hopewell.

 

[littlepod]

The gun that I'm currently competing with at 200yds is a Diorio V3 Turbo. Shilen ratchet, Bix trigger, Nightforce 12x55. Diorio tuner which is basically a modified Harrels. I shoot off a Pappas one piece and sometimes a Seb Neo. The barrel is weight tuned using my own tunning procedure which is a modified Hopewell.

Thanks! Did you tune at 200? Or did you notice that the tune you found was universally good at all distances?

 

[flatland1]

I started out putting a SFP Pro-X tuner on my V22S, and was so impressed that I bought another one for my oldest V22 repeater. Then decided to experiment with a couple of Harrells tuners on the repeaters. What I'd like to try is a front bushing for the Harrells that's similar to what the Pro-X tuners use. I've looked back through most of this thread, but failed to find any reference to a bushing that will fit the large dia internal threads of the Harrells, nor have I seen any reference to bushings on Harrell's website. Anyone know if there's something ready made available for sale? If not, I've made them out of 6061 for the Pro-X, and could make them for the Harrells...if I had the thread specs.

 

[6.5SH]

There are threaded weights and bloop tubes:

Benchrest Tuners | Killough Shooting Sports

Improve your accuracy with the latest selection of benchrest tuners at Killough Shooting Sports. Same day dispatch on orders before 2 pm.

www.killoughshootingsports.com

 

[littlesister]

Thanks! Did you tune at 200? Or did you notice that the tune you found was universally good at all distances?

I tune at 50 and let it ride. If I had access to a 100 or 200yd indoor range I might give it a try, but I don't. I've said this before. It's impossible to tune a 22lr outdoors at 200yds! !00yds outdoors? Maby with the right conditions .but it would still be very difficult. My statements are based on my own shooting experience. I have been shooting a 200yd golf ball match for over 5 years. We shoot all 12 months no matter what conditions. 10 sight in shots 10 shots for score. I've put a lot of 10x and Midas+ down range. In five years I've never shot clean! 8 out of 10 is my best. Actually no on has ever shot 10 for 10. A 22lr is simply unpredictable past 100. no matter what gun what ammo or what tune.

 

[littlepod]

I tune at 50 and let it ride. If I had access to a 100 or 200yd indoor range I might give it a try, but I don't. I've said this before. It's impossible to tune a 22lr outdoors at 200yds! !00yds outdoors? Maby with the right conditions .but it would still be very difficult. My statements are base on my own shooting experience. I have been shooting a 200yd golf ball match for over 5 years. We shoot all 12 months no matter what conditions. 10 sight in shots 10 shots for score. I've put a lot of 10x and Midas+ down range. In five years I've never shot clean! 8 out of 10 is my best. Actually no on has ever shot 10 for 10. A 22lr is simply unpredictable past 100. no matter what gun what ammo or what tune.

Yeh I believe you! Outdoors golfball is really hard... I have tried it a few times, and while you might get on a streak of 4, I think the best I've done is like 6-8 out of 10 shots for golfball, and I also have a backing that lets me spot my misses easily to make corrections.

 

[Arkansan]

Does Purdy ever say that Harrell tuners may or may not work with his "method"?

The only thing he states in the formula is, the second EC is used if the outer shell is more than 1/4" past the inner tube. :On my Harrell's, this doesn't happen until I have adjusted into the 400 range and we are past the mid range which is "supposed" to be the area where tuners function best.
My guess is, with the Harrell's it is not the 9th harmonic and you need an extension to get best results. Orkan had excellent results using a 1" extension and his PL of 29.553 hits fairly close to 7th harmonic numbers. I just did a 7th Harmonic calculation for 24 and 26 inch barrels. The 26 PL is 29.73, the 24 PL is 27.42. When I factor in a 1" extension for my Harrell's, both are within Purdy range and I will have the outer shell well past the inner shell which I think is key to a tuner's best function. Looking at Orkan's results and the design change when the extension is added, I think this will work. Harrell's does not have the extensions on the website, you have to call to order them. They have a 1/2" and 1" steel and 3oz 1" aluminum.

 

[littlesister]

The only thing he states in the formula is, the second EC is used if the outer shell is more than 1/4" past the inner tube. :On my Harrell's, this doesn't happen until I have adjusted into the 400 range and we are past the mid range which is "supposed" to be the area where tuners function best.
My guess is, with the Harrell's it is not the 9th harmonic and you need an extension to get best results. Orkan had excellent results using a 1" extension and his PL of 29.553 hits fairly close to 7th harmonic numbers. I just did a 7th Harmonic calculation for 24 and 26 inch barrels. The 26 PL is 29.73, the 24 PL is 27.42. When I factor in a 1" extension for my Harrell's, both are within Purdy range and I will have the outer shell well past the inner shell which I think is key to a tuner's best function. Looking at Orkan's results and the design change when the extension is added, I think this will work. Harrell's does not have the extensions on the website, you have to call to order them. They have a 1/2" and 1" steel and 3oz 1" aluminum.

One thing you might consider on a Harrels is to shorten the inner tube. Ihe outer most portion of the inner tube is threaded . I believe these threads are for adding a bloop tube. You can cut this portion of the inner tube off flush with the inner threads without effecting the linear adjustment of the outter shell. The extensions and or weights screw into the outer shell if I'm correct.

 

[flatland1]

Thanks for the info on the extensions for the Harrells tuners. Just got off the phone with Killough's - have all three of the extensions coming to experiment with. I'd bought 2 black Harrells tuners for my two V22 repeaters - one with a 21" Krieger sendero, the 2nd with a 22" Bartlein Kukri. I'd also worked with a Pro-X tuner on the Krieger sendero, using the Purdy prescription, and had seen significant improvements at 50, 100, & 200yds with the same scrip. Just recently finished a new Three-60 action build with another Krieger sendero, but finished it at 23". Would love to be out shooting it with the Pro-X right now, in hopes of finding a good enough tune to take it to a match this coming Sunday, but we've got gusts above 50mph and have had pretty much all afternoon. The sky is brown, and if we don't get some significant precip in the next week or so, I'll have more important things to worry about than tuning .22s...

 

[littlepod]

Thanks for the info on the extensions for the Harrells tuners. Just got off the phone with Killough's - have all three of the extensions coming to experiment with. I'd bought 2 black Harrells tuners for my two V22 repeaters - one with a 21" Krieger sendero, the 2nd with a 22" Bartlein Kukri. I'd also worked with a Pro-X tuner on the Krieger sendero, using the Purdy prescription, and had seen significant improvements at 50, 100, & 200yds with the same scrip. Just recently finished a new Three-60 action build with another Krieger sendero, but finished it at 23". Would love to be out shooting it with the Pro-X right now, in hopes of finding a good enough tune to take it to a match this coming Sunday, but we've got gusts above 50mph and have had pretty much all afternoon. The sky is brown, and if we don't get some significant precip in the next week or so, I'll have more important things to worry about than tuning .22s...

I'll be curious how it works out. With the holeshot tuner, the Purdy formula worked out with the tuner without extensions for a 22" barrel. I believe there's only .5" of extension (500 settings) on the holeshot so if I was going to do a 24" barrel I would need an extension but for 22" I was fine.

 

[Arkansan]

Does the Holeshot have an inner tube that protrudes to or past the outer shell like the Harrell's? Could you post a picture of the "working" end? Looking at other tuners, I think the Harrell's needs the extensions to take full advantage of the design.

 

[littlepod]

The holeshot tuner has an inner tube that's pretty much protrudes a little less than the outer shell. I'd have to be around the 200 setting or so for the outer shell to be 1/4" past the inner tube which then changes the EC portion of the Purdy formula. The holeshot tuner is based off of Hopewell tuning so they don't really talk much about extensions and stuff. They do make a weight kit for it too the PQP weight kit that'll screw right on.

 

[Arkansan]

Thanks
Probably similar to the Harrell's extensions, a 3 oz 1" aluminum and a 1/2" and 1" heavier metal ones.. Looking at Orkan's success with the 1" and doing some Purdy, I think a 7th harmonic calculations will get in the ballpark followed by Hopewell fine tuning which I will do even with the ProX and JNL just to verify the setting. The JNL and Pro X look identical with the JNL having clear and distinct adjustment markings. I need magnifying glasses to adjust the silver Harrell's and ProX. KSS has the JNL and bushings like ProX but, will provide it machined to fit, the ProX needs to be fitted by a gunsmith. If I get another, it will be JNL. and I would use the adjustment guidelines from the ProX website since they are so precise. One possible advantage to the ProX is, there are also 3.65 oz threaded weight adapters that can be added to the front of the tuner to add weight and length. I found a picture of the Hoen with a test showing it as quite effective. Inside it looked a lot like the Purdy tuners, no threaded tube. I found this pictue before I parted with the rifle. I contacted the dad of the young man that won it and he indicated the barrel length is 23 1/4" and the tuner set at 214.
I need to mess with the numbers and see how this corresponds to the PRX tuners. BTW, rifle was a thing of beauty. Part of a number of rifles built by an old shooter who apparently developed Alzheimers. He took what looked like a german barrel (from the markings) a Vostok action which he apparently cut and sleeved on a beautiful Anschutz cadet stock. He built an aluminum (plank) to go in the forearm groove for the front rest. It was a great shooter, just didn't fit me. The young fella who has it was able to shoot it in a match and won. It got a good home.. Looking at the full picture, I see that it looks like about a 1" weight on the front.

 

[littlepod]

Thanks
Probably similar to the Harrell's extensions, a 3 oz 1" aluminum and a 1/2" and 1" heavier metal ones.. Looking at Orkan's success with the 1" and doing some Purdy, I think a 7th harmonic calculations will get in the ballpark followed by Hopewell fine tuning which I will do even with the ProX and JNL just to verify the setting. The JNL and Pro X look identical with the JNL having clear and distinct adjustment markings. I need magnifying glasses to adjust the silver Harrell's and ProX. KSS has the JNL and bushings like ProX but, will provide it machined to fit, the ProX needs to be fitted by a gunsmith. If I get another, it will be JNL.

For your 22" and 23" barrels I'd try to tune with the Harrell's as-is with Hopewell and I think you'll find a tune. The formulas for the 9th harmonic seem to work fine for 22" (no shorter for the harrell's)

 

[Arkansan]

I'll be doing the shooting (if the winds ever die) with my 24" Shilen ratchet. Looks like Purdy puts the Harrell;s in the lower 200 range. Now, going to the ProX, when I use the their formula for this barrel, it calls for a 193 setting which will make the PL in the 26.7" range but the Purdy formula comes up with a PL of roughly 26.9. That seems like a pretty significant difference. Guess I'll see when the bullets go downrange. Also, when I measure and recalculate my 20" barrel with the JNL and I verify the 153 setting that Joe preset, using the ProX table the PL is 22.25. Using the Purdy formula, I get roughly 22.50 once again a difference of roughly .2" which from what I see in Hopewell is a lot. This is going to be interesting. I will definitely be doing some Hopewell. Bullets don't lie.

 

[Williwaw]

Arkansan, you are right, 200 thous is a load of difference when a good tune is optimal at plus or minus a click which is one thous on a Harrell.

 

[Hoser]

I am a total hack when it comes to most things.

Here is what I did with my 20 inch Vudoo 360. 5 shot groups at 50 yards. ATS tuner, Thunderbeast suppressor. Random known good lot of SK. Accuracy went from zero to hero in 4 settings. I quit while I was ahead.

 

[littlesister]

I am a total hack when it comes to most things.

Here is what I did with my 20 inch Vudoo 360. 5 shot groups at 50 yards. ATS tuner, Thunderbeast suppressor. Random known good lot of SK. Accuracy went from zero to hero in 4 settings. I quit while I was ahead.

Great example of a tunned barrel! One thing I might add is after you have found that setting stop shooting and wait at least about 20 min. and shoot another group. If it repeats, You probably have the true tune.

 

[Williwaw]

I am a total hack when it comes to most things.

Here is what I did with my 20 inch Vudoo 360. 5 shot groups at 50 yards. ATS tuner, Thunderbeast suppressor. Random known good lot of SK. Accuracy went from zero to hero in 4 settings. I quit while I was ahead.

I doubt the veracity of the total hack comment.
In going from 8 to 2 is the tuner moving in or out?

 

[grauhanen]

Here is what I did with my 20 inch Vudoo 360. 5 shot groups at 50 yards. ATS tuner, Thunderbeast suppressor. Random known good lot of SK. Accuracy went from zero to hero in 4 settings. I quit while I was ahead.

Those are nice results at the fourth setting (2). Are all follow up groups at the same setting equally impressive?

 

[Arkansan]

Just got a chance to shoot.. Some breeze, not bad. I set 197 on the ProX using their numbers. Pretty good. Then I went to 200 205 210 and they didn't look good. On a hunch, I tried 195 since I didn't bring the crown into my initial computations, and at 75 yds got a 4 shot group of .25". I need to do more with some other ammo, but it looks promising. Now, the ;question I have is, did the tuner really help? I am going to pull it Since this barrel that seems to be at the top of the heap in benchmark (with the Mueller), it may be that at the recommended 24", it will shoot that well bare. I'll try at some point to add in the .20"+ I got from the Purdy formula reset the tuner and see what happens. I am using a chamber that has dimensions like a Caffee 2, but .227 at the base (like a 52D, 2278.), longer throat, .67 vice .60 and 1 1/2 degree leade. So far I am very pleased, especially for a $50 reamer. I had Jelrod set it up to just touch the lands per recommendation from Kevin Nevius.(super nice guy). I need to punch a lot more holes to make sure this wasn't a fluke.

 

[littlepod]

Just got a chance to shoot.. Some breeze, not bad. I set 197 on the ProX using their numbers. Pretty good. Then I went to 200 205 210 and they didn't look good. On a hunch, I tried 195 since I didn't bring the crown into my initial computations, and at 75 yds got a 4 shot group of .25". I need to do more with some other ammo, but it looks promising. Now, the ;question I have is, did the tuner really help? I am going to pull it Since this barrel that seems to be at the top of the heap in benchmark (with the Mueller), it may be that at the recommended 24", it will shoot that well bare. I'll try at some point to add in the .20"+ I got from the Purdy formula reset the tuner and see what happens. I am using a chamber that has dimensions like a Caffee 2, but .227 at the base (like a 52D, 2278.), longer throat, .67 vice .60 and 1 1/2 degree leade. So far I am very pleased, especially for a $50 reamer. I had Jelrod set it up to just touch the lands per recommendation from Kevin Nevius.(super nice guy). I need to punch a lot more holes to make sure this wasn't a fluke.

I had read some threads since tuning is about getting the right tune to minimize the spread on different velocities that they'd just intermix ammo, like get 2 lots of center-x one rated 28xx and one rated 25xx and just interleave the ammo.

The issue with my Midas+ is that right now it has an SD of 5 and I can get a lot of rounds in a row w/o any real change which then is hard to really test the tune reliably without sending a lot of rounds down.

 

[Williwaw]

I had read some threads since tuning is about getting the right tune to minimize the spread on different velocities that they'd just intermix ammo, like get 2 lots of center-x one rated 28xx and one rated 25xx and just interleave the ammo.

The issue with my Midas+ is that right now it has an SD of 5 and I can get a lot of rounds in a row w/o any real change which then is hard to really test the tune reliably without sending a lot of rounds down.

My hat is off to you littlepod, you are really doing your homework.

I have a question to put to you, and Arkansan too for that matter. What are your accuracy or precision requirements? For myself I need a 40 shot composite group made up of eight bulls of five shots to be no larger than .58 inches. That gives me no room to be off 1/3 of a click on my scope so 0.5 is a better number. Therefore if I can wring out .2 inches off MV variance induced vertical I'm a happy old man. I wouldn't mind being even tighter so as to up my X count.

I raise this question because we are on the Hide as opposed to Benchrest Central. I think there may be a lot of guys using tuners whose rifles may or may not really be optimized and it doesn't matter anyway given the nature and the requirements of the game they are in.

Do you guys think this is a fair observation?

 

[Arkansan]

I am shooting a Rimx off the ground, bipod and bag at the butt. My objective is the best consistent groups I can. I doubt that I will ever get involved in a competition shoot. Looking at what I've seen these rifles capable of, my goal is to get consistent 1/2 moa hopefully better. I'll be shooting mostly at 75 yards since that is where I can get shade and then I can move into the woods where I have cut a 200 yd range. I just enjoy accurate firearms. The .22 pistol I just got has a .40" test group at 50 yds. Can I duplicate that? Probably not, but I know it is capable. I am shooting a number of lots of lower priced Eley ammo and have been impressed with the results. I have been playing with different disciplines since I was in my 50's and now I'm getting closer to 80. I like to learn and this is turning into a great learning process.

 

[Williwaw]

In another thread Arkansan said:
I guess the question is, what are the guys in the winner's circle using? Is there any success with the shorter, tuned to harmonics tuners?

Hey Arkansan,

Hope it is ok with you that I pulled this back into this thread. It will make this easier to follow. I messed up when I posted over there.

I never embraced Purdy for one reason only and that is that it never made sense to me. When I was new at this I searched and scratched to find anything I could on tuning. As I understand Purdys equation it calculates the nodes of various harmonics of waves in a closed end tube. On the surface that appears to make sense since obviously our barrels are tubes with one end closed. What I could never get is any explanation of why that mattered and I couldn't think of one myself.

In contrast, the theory of tuning for positive compensation does make sense to me and a couple guys way smarter than me have done the work.
Dr. Kolbe is one who has done the experimental proof and VarmitAl the computor modelling based on the math of an oscillating horizontal beam with one fixed end.

The manufacturers have not limited their market by taking a stand, most make devices that accommodate both approaches. In this endeavor of tuning 22 rimfire rifles it is possible to be right for all the wrong reasons, ie. you can have a good tune without having any idea what you really did. I surely pray I am not coming off as arrogant here. I'm still new at this and I'm sure there are things I believe to be so that ain't.

 

[Arkansan]

No arrogance what so ever. For me it is like computers, I do not want to know how to make one, just get one that works. This is where I am with tuners. I just shot today with the Prox. The good thing about this one is, though designed around Purdy, it has weights available also. I may try some at some point however, I believe there is a point that you can only go so far with any of these devices.

 

[Williwaw]

I am shooting a Rimx off the ground, bipod and bag at the butt. My objective is the best consistent groups I can. I doubt that I will ever get involved in a competition shoot. Looking at what I've seen these rifles capable of, my goal is to get consistent 1/2 moa hopefully better. I'll be shooting mostly at 75 yards since that is where I can get shade and then I can move into the woods where I have cut a 200 yd range. I just enjoy accurate firearms. The .22 pistol I just got has a .40" test group at 50 yds. Can I duplicate that? Probably not, but I know it is capable. I am shooting a number of lots of lower priced Eley ammo and have been impressed with the results. I have been playing with different disciplines since I was in my 50's and now I'm getting closer to 80. I like to learn and this is turning into a great learning process.

Clearly tuning is totally relevant to what you are about. And you have set yourself a high standard. I'm going to finish case of SKRM in the next week and I have what I feel is a valid tune. Would you like to do the Purdy calculation for me to see where I am? Let me know what measurements you need if so.

 

[littlepod]

My hat is off to you littlepod, you are really doing your homework.

I have a question to put to you, and Arkansan too for that matter. What are your accuracy or precision requirements? For myself I need a 40 shot composite group made up of eight bulls of five shots to be no larger than .58 inches. That gives me no room to be off 1/3 of a click on my scope so 0.5 is a better number. Therefore if I can wring out .2 inches off MV variance induced vertical I'm a happy old man. I wouldn't mind being even tighter so as to up my X count.

I raise this question because we are on the Hide as opposed to Benchrest Central. I think there may be a lot of guys using tuners whose rifles may or may not really be optimized and it doesn't matter anyway given the nature and the requirements of the game they are in.

Do you guys think this is a fair observation?

I shoot prone off a bipod and rear bag. I primarily compete in NRL22 / PRS Rimfire competitions and you don't really need the extra 20% precision as your wind call is what is important, and shrinking a group vertically by .2" at 100yards isn't going to do much when your wind call is off by 3".

On the off weekends I was considering shooting some 100y / 200y F-class matches so that's why I got the tuner to see if it'd help. While I didn't get as much verification at 100y on my tune as I'd have hoped, I did notice my 50y groups felt more consistent. I'll put up a USBR target for fun one day and just see how I do.

This was prior to the tuner, I got to give this a try sometime when there isn't a big muzzle braked center-fire next to me.

 

[Arkansan]

The Purdy Prescription___(the Rx for tuning your tuner)

The Purdy Prescription Thank You for giving my idea a try. Together we will work thru what I believe will be an effective, if not best, tune for your rifle. My tuning is based on the harmonics that develop in a closed end tube when excited, and putting the muzzle at the even quarter wave in...

www.rimfirecentral.com

Williwaw
I'm not using the formula. I found getting the precise number using the table with the tuner from CST for the ProX a lot easier and more precise. It gives a specific number to set and seems to work. This post by Tony Purdy may be helpful. The computation is straightforward, but getting precise measurements not as easy. I may try it when/if I try the Harrell's but, after today, I am happy with the results and surprised how much just a slight variation does when adjusting the tuner. When I used the CST "formula" to check the number preset on a tuner I got from Joe Chacon, the number was the same. The 2 tuners look identical.

 

[littlepod]

Went out today to try tuning at 50, it was a calm day with only 3mph winds and tuning at 50 versus 100 to see how the tuning nodes would be. I dialed .4mils down from the center so I could have a consistent aiming spot.

Last time I ended up with a tune setting of 11, and also I had a possible good node in the 75 bracket, so I should test 65-85 to see. I also chrono'd every round I fired to see if the group was really being tuned well or if it was just a good ES/SD group, so every time 10 shot group I could see the ES range and how it affected the group sizes.

Here's 50 yards, all 10 shot groups. T is the tuner setting, then the MV velocity range. I started at 11, then I tried 13 and it did not look good. Then I did 65, 70, 75, 80, 85. And it looked like between 75-85 the groups handled the wide 30 ES pretty well. Tuner 70 looked pretty good, but the ES for those 10 rounds was only 14. I then tweaked between 79 and 81, and landed on either 79, 80, but I have it set to 80 right now.

I shot my friend's CX, which averages an SD of 7 and an ES of 24 and it was amazing. My Midas+ is generally an SD of 9 and an ES of 33, but it does have the occasional swings, like an ES of 48 (1043 to 1091!)...

At 200 yards it's hard to tell if the tuning is doing much at all... ES seems to dictate most of the group size. I don't think tuning could make it worse, but for some of the strings being only an ES of 17-18, I expected more in the 2" group size

 

[Arkansan]

Got a pleasant surprise the other day. I have a chassis sitting idle and since I ordered some Vudoo mags to try with the Rimx, decided to pull the trigger on a Vudoo action. I was quoted a 4-6 week wait but, 2 days after placing the order was told it had been shipped. I have a GM barrel, that after initial problems, had rechambered to 52D. I had Dave Manson cut one of his Bentz reamers for me since other than the leade and length, the dimensions were the same.. The 52D has a lot of engraving which goes against most "conventional wisdom" however it shot extremely well. Dave's Bentz is definitely tighter than published Bentz specs, .227 taper to .2255 and at 50 bucks, a good buy. Since the Bentz chamber is .090 longer than the 52D, I decided to have JElrod rechamber the barrel again to reduce land engagement and see how it shot before doing another barrel. Land engagement is .050 so it is a good range according to Kevin Nevius' recommendation. .030 for Lapua and .090 for Eley..
I just got in from initial testing. I needed to check the scope after swapping barrels and really wanted to wait since the wind is gusting at 20-25. I shot at just over 40 yds and initial group was .19". It shot well with the 52D chamber, but as expected, this is better. I am now comfortable going with the Manson Bentz chamber with the 26" ratchet Vudoo. This will give me another test bed to be able to do the Pro-X/Harrell's comparison. When/if it calms down, I'll do some bare barrel and tuner testing with the GM and then the 24" Shilen. The GM barrel ended up at 19.75". Who knows, maybe this will be a "magic" length and all the planets, harmonics, and weight thingies will fall into alignment.
It will be interesting to see how it "tunes". The Pro-X with 1/2" bushing puts it in a good range. I just need to put up a bunch of non-tuner targets to settle on a lot/type of ammo and then do some tuner testing.

 

[littlepod]

Got a pleasant surprise the other day. I have a chassis sitting idle and since I ordered some Vudoo mags to try with the Rimx, decided to pull the trigger on a Vudoo action. I was quoted a 4-6 week wait but, 2 days after placing the order was told it had been shipped. I have a GM barrel, that after initial problems, had rechambered to 52D. I had Dave Manson cut one of his Bentz reamers for me since other than the leade and length, the dimensions were the same.. The 52D has a lot of engraving which goes against most "conventional wisdom" however it shot extremely well. Dave's Bentz is definitely tighter than published Bentz specs, .227 taper to .2255 and at 50 bucks, a good buy. Since the Bentz chamber is .090 longer than the 52D, I decided to have JElrod rechamber the barrel again to reduce land engagement and see how it shot before doing another barrel. Land engagement is .050 so it is a good range according to Kevin Nevius' recommendation. .030 for Lapua and .090 for Eley..
I just got in from initial testing. I needed to check the scope after swapping barrels and really wanted to wait since the wind is gusting at 20-25. I shot at just over 40 yds and initial group was .19". It shot well with the 52D chamber, but as expected, this is better. I am now comfortable going with the Manson Bentz chamber with the 26" ratchet Vudoo. This will give me another test bed to be able to do the Pro-X/Harrell's comparison. When/if it calms down, I'll do some bare barrel and tuner testing with the GM and then the 24" Shilen. The GM barrel ended up at 19.75". Who knows, maybe this will be a "magic" length and all the planets, harmonics, and weight thingies will fall into alignment.
It will be interesting to see how it "tunes". The Pro-X with 1/2" bushing puts it in a good range. I just need to put up a bunch of non-tuner targets to settle on a lot/type of ammo and then do some tuner testing.

I'd be curious how the 19.75" works out. It seems like that's too short for the 9th harmonic calculation, but probably can try something like the 7th harmonic.

 

[flatland1]

I may have to try a spare Harrells tuner on the GM bbl that I recently chambered & installed on my Rim-X - I put 60rds of SK Std+ (2 lots, one very good), SK Rifle match (2 lots, one very good), SK Pistol Match (one very good lot), and SK LR Match (one good lot) through it at 50yds a couple of evenings ago after the breeze had died down. I had several groups that were pretty decent, but there always seemed to be a flier or two. As I said, I've already got the spare Harrells tuner, and I recently bought all three of the weights/bushings that Killough carries for the Harrells, so what have I got to lose besides the time & ammo? I would need to bore the tuner out a bit larger, as Harrells bored it to fit the Bartlein Kukri on my 2nd V22 repeater, and the Keystone Accuracy sport Palma contoured GM bbl is still .918" at the muzzle, even though I finished it at 23".

 

[Arkansan]

The Pro-X is designed for the 9th. They have specific bushings for different barrel lengths. Tuner and 1/2" for 18.424" -21.624". Deducting .050 for my crown = 19.70" Calculation is 19.70 - 18.424 = 1.276 divided by 8 = .1595 which is the micrometer setting. I tried it with the 24 and was happy with the results, didn't pursue it since I needed verify my GM chamber. When I plugged the numbers into my 20" Kidd barrel with JNL tuner, the number matched what Joe had set in when I ordered his tuner and the improvement with the Kidd barrel was obvious. After I have sorted through some types and lots of ammo, and have some bare barrel results, I will stick the tuner on the GM barrel. I may try the Harrell's on the 24 or just wait for the 26. Pro-X has bushings (or bare) for barrels from 15.37" to 27.624". The also have a brass weight that is threaded to accept bushings. I don't have a bushing for the 26" barrel, but will probably order one as well as a brass weight to see if it helps.
As I mentioned before, when I do a Purdy calculation and compare it to the PRO-X length there is a .20" difference. At some point I'll see what happens with this number.

 

[Arkansan]

I'd be curious how the 19.75" works out. It seems like that's too short for the 9th harmonic calculation, but probably can try something like the 7th harmonic.

It should be fine. I have a 1/2" bushing which tunes to the 9th for barrels from 18.424 to 21.624. Weather has been bad. no shooting for a while between the wind and rain. Unfortunately, for a 22" barrel, JNL does not offer a 3/4" bushing is roughly for 20+to 24" barrels. I don't know how much of a difference it makes,but the recommendations I've seen are that tuners function best when set in their mid range.
The good news is, I just heard from Jelrod and he has finished my 26" Shilen ratchet Vudoo which I had him chamber with an Eley Ultimate EPS reamer PTG had in stock. I chose this since I will be primarily shooting ELEY and saw a recommendation from Calfee that with current barrels being close in tolerance to use his #2 reamer which is a straight no taper .225", the same specifications as the Eley Ultimate. Taking that recommendation plus Kevin Nevius recommending .090 land engagement and 2 degrees for Eley.
Since I chambered my Rimx Shilen with the Bentz, which is close to Kevin's recoimmendation for Lapua with a 1 1/2 degree leade and .030engagement, I will be able to make some comparisons using various types of ammo I have stocked up. At some point, I'll put the 19.75" barrel back on and see how the tuner works. Unfortunately, initial comparisons look like it may have shot better with the 52D chamber which was a Manson Bentz I had cut back to 52D specs.. I won't be able to do a Harrell's/PRX comparison. I had to send the Harrel's back (again} to be recut since my .850 barrel mealsured .860". What I may do, is try the Harrell's with and without the 1" outer tube extension. Externally, it looks a lot like the Hoehn with the extension added.
Now, all I need is an extended break in the weather.

 

[Arkansan]

Looks like my chamber search may be over. I just got this test group from Jonathan. 26" Shilen ratchet with Eley Tenex PTG Ultimate EPS Reamer Vudoo action. The chamber has the same specs as the Calfee 2 (.220 no taper) which he says is the one to use with current barrel dimensions. It will be interesting to see how it does with the tuner. I have it set up to start with the number Orkan provided with the Harrell's and 1" weight. I have an assortment of Eley and SK to test with. I have another Shilen with a 1.5 degree leade I chambered since Kevin Nevius recommends this for Lapua on the Rimx that I'll probably let go and use the EPS reamer on my last Shilen to go on the Rimx. I need to do some shooting with it first as well as the GM I have inbound with Eachus chamber.
It's nice to have a gunsmith who takes the time to verify his work and not just machine a blank and send it out.

 

[Broncolou]

Deleted…..Old info

 

[Stephen T]

It should be fine. I have a 1/2" bushing which tunes to the 9th for barrels from 18.424 to 21.624. Weather has been bad. no shooting for a while between the wind and rain. Unfortunately, for a 22" barrel, JNL does not offer a 3/4" bushing is roughly for 20+to 24" barrels. I don't know how much of a difference it makes,but the recommendations I've seen are that tuners function best when set in their mid range.
The good news is, I just heard from Jelrod and he has finished my 26" Shilen ratchet Vudoo which I had him chamber with an Eley Ultimate EPS reamer PTG had in stock. I chose this since I will be primarily shooting ELEY and saw a recommendation from Calfee that with current barrels being close in tolerance to use his #2 reamer which is a straight no taper .225", the same specifications as the Eley Ultimate. Taking that recommendation plus Kevin Nevius recommending .090 land engagement and 2 degrees for Eley.
Since I chambered my Rimx Shilen with the Bentz, which is close to Kevin's recoimmendation for Lapua with a 1 1/2 degree leade and .030engagement, I will be able to make some comparisons using various types of ammo I have stocked up. At some point, I'll put the 19.75" barrel back on and see how the tuner works. Unfortunately, initial comparisons look like it may have shot better with the 52D chamber which was a Manson Bentz I had cut back to 52D specs.. I won't be able to do a Harrell's/PRX comparison. I had to send the Harrel's back (again} to be recut since my .850 barrel mealsured .860". What I may do, is try the Harrell's with and without the 1" outer tube extension. Externally, it looks a lot like the Hoehn with the extension added.
Now, all I need is an extended break in the weather.

OK I’m confused. My Vudoo v22s has a muller 26” barrel w/.044 head space & 11^ crown. I use a Harrell without any added spacers. It’s set at .167 for now. My question is what is the Purdy length I need to be at and which spacer to add to get there, also Aluminum or Steel?

 

[Arkansan]

OK I’m confused. My Vudoo v22s has a muller 26” barrel w/.044 head space & 11^ crown. I use a Harrell without any added spacers. It’s set at .167 for now. My question is what is the Purdy length I need to be at and which spacer to add to get there, also Aluminum or Steel?

After so much discussion of pros and cons and the different numbers I have come up with comparing Purdy formula and the lengths I have observed measuring Purdy formula based tuners, JNL-PRX and SFP Pro X, I decided to try something different. The Pro X gives very specific settings for different barrel lengths and the pre-set PRX I have corresponded with these measurements however, when I did Purdy calculations, they differed a little. I have no explanation but, the set up Joe sent me and the SFP setting work. I'm not convinced I can get a good OAL calculation for the Harrells so I took a known result. If you go got post 129, you will see some actual results from a well known and respected contributor, ORKAN. This is what I based my build on, 26" barrel and when I measured my Harrell's, I saw that I needed the 1" extension to achieve the 3.553" I need to duplicate his results, I am moving and have packed my gear so I can't verify the numbers, but I think if you get the 1" aluminum extension and do the measurement and stick it on you will be very close to your desired results.
Short answer, 1" extension, stick it on, mike the tuner to 4.7553, 4.7553-1.2=3.553 and go shoot.
I had my Vudoo in reach, too long with the tuner for the case but the tuner measures 4.75" and the setting is 219.

 

[Cuzz]

The tuner arrived today. I'm pretty excited. I ordered this Tuesday evening and was pleasantly surprised when I opened the mailbox today. The weather looks good tomorrow and I have time to go to the range. I didn't see any instructions on the amount of torque for installation, I just went with 10 in. lbs.

 

[littlesister]

OK I’m confused. My Vudoo v22s has a muller 26” barrel w/.044 head space & 11^ crown. I use a Harrell without any added spacers. It’s set at .167 for now. My question is what is the Purdy length I need to be at and which spacer to add to get there, also Aluminum or Steel?

OK I'm confused also! Why are you wanting to add weight/length to your stock Harrels? A standard Harrels will tune a 26in barrel without adding any weights or length. If you can't find a good tune then you need to look at the gun for other possible problems. As to the Purdy method. I don't use it. I've checked it against guns that were known to be in tune. Sometimes it would be close and sometimes not. But we're not playing horseshoes. Close isn't good enough. You're either in tune or out. One click on a Harrels can make a difference. One other thing. You can't tune a barrel over the internet