What would you consider match accuracy?

[JBoomhauer]

Seems many shooters here insist that CCI SV performs exceptionally well at 50 yards. They have a very low bar for accuracy.

JBoomhaurer, you changed my question more to your liking. In doing so you succeed in not having to address the reasonable question I did ask. Ducking it after a lot of answers have been given for your (and the OP's) question, suggests you would prefer some things should remain unexamined.

 

[TurboTrout]

Well I’d say your rig needs to be able to run the match,

So at 50yrds your rig should be able to make consistent hits on a 0.25” swinger

Sub MOA at 100

Most SK and most Eley will easily do this with my Sako P94S

 

[obx22]

Rimfire accuracy isn't linear. That is to say, when the distance is doubled results are more than doubled.

Having said that, for what reasons would an ammo that shoots exceptionally well at 50 not continue to perform well at further distances?

There are a bunch of theories, but until I can see something like shadowgraphs of fired rounds at distance, or when video focus gets fast enough to follow a slugs flight, it’s the best we can offer.
I’ve seen rimfires that keyholed at distance, but it was rare. I’ve seen bullets fly in a helix to the target, but it’s also rare. I’d recommend searching the treatise “How Do Bullets Fly” for an explanation of what could be going on.
In the firing process every slug is deformed by the rifling (duh, you knew that), but it’s also not that pretty round you loaded in the mag either. It’s scraping all the crap out of the bore that was resting primarily from 8:00 to 4:00 in the bore, and while some sluffs off as the slug exits, not all of it does. Some rides along at the front of the driving bands, ironed into the lube. The bullet’s heel, flared by pressure and stripped from the case mouth has lots of little irregularities as it reaches the barrel’s crown and the pent up gasses go blasting past, upsetting the base. Lots of little inconsistencies all adding up to cause that slug to drift away from the group. It’s a wonder we hit anything at all.
One question no one has asked, is why some gun/ammo combo’s group poorly close up, but seem to improve down range…..

 

[obx22]

There are a bunch of theories, but until I can see something like shadowgraphs of fired rounds at distance, or when video focus gets fast enough to follow a slugs flight, it’s the best we can offer.
I’ve seen rimfires that keyholed at distance, but it was rare. I’ve seen bullets fly in a helix to the target, but it’s also rare. I’d recommend searching the treatise “How Bullets Fly” for an explanation of what could be going on.
In the firing process every slug is deformed by the rifling (duh, you knew that), but it’s also not that pretty round you loaded in the mag either. It’s scraping all the crap out of the bore that was resting primarily from 8:00 to 4:00 in the bore, and while some sluffs off as the slug exits, not all of it does. Some rides along at the front of the driving bands, ironed into the lube. The bullet’s heel, flared by pressure and stripped from the case mouth has lots of little irregularities as it reaches the barrel’s crown and the pent up gasses go blasting past, upsetting the base. Lots of little inconsistencies all adding up to cause that slug to drift away from the group. It’s a wonder we hit anything at all.
One question no one has asked, is why some gun/ammo combo’s group poorly close up, but seem to improve down range…..

How do bullets fly?

How Do Bullets Fly

 

[JG26_Irish]

I can offer my opinion. Based on my PRS rifle and multiple data sources. Rifle is a Sako Quad Custom with Lilja bbl using a Arken SH4 6-24x FFP MIL optic. Lapua CX ammo. Most outside of the test center data was shot as 5shot groups measured center to center from bipod & rear bag on a bench or prone. In general I consider match accuracy at 50y to be 0.25" c-c with match grade ammo. Some rifles will on occasion do better but few (none) can do better "All day long". The only factory rifles in this class are Annies and Winchester 52's (maybe VuDoo?), I think of VuDoo as more of a factory custom than a true production rifle. To print 1/4" c-c you have to print 12mm edge to edge which is how the Lapua test center measures 10shot groups at 50 & 100 meters (55-110y). 10 shot groups are statistically larger and the 10% longer distance also tends to make them bigger.

For the Sako, the ammo I am currently using printed 10 shots into 17.42mm @ 50m and 34.62mm @ 100m (0.46" and 1.14" c-c). I am usually able to hit a 1" and 1.5" plate prone at 100y. To hit a 1" plate at least on the edge means I must shoot inside of a 1.45" circle. That is about the capability of the Sako. My factory CZ457 VPT is about 1mm larger groups with the same ammo.

I have never made a habit of shooting paper at 200y or further but have on few occasions. At 200y if you can group 2.5" or less you are doing really well. That is what the Sako does in good calm conditions. At these longer ranges the wind becomes much more of a factor as does spin drift. Spin drift is more about hitting the tgt since it is a deviation but more or less constant in one direction. Groups at this range become oblong in the vertical due to ammo inconsistency.

At 200y we shoot a 6" plate (easy) and a 3" plate, less easy. I find both to be very doable with the Sako. We also have shot a bird shaped plate about the size of Robin at 185y and found head shots on it from a bench to be a chip shot. Not sure if that means much.

Next is 300y. We are shooting a 8" plate at that distance. I find it the hardest to get on tgt due to a bunch of factors but once dialed in, I can ring that plate 9 of 10 shots. Wind being a big factor here and am assuming the wind remains steady that long. I can see hits on steel or holes in paper at 300y with this optic and usually the hits are centered well most of the time. In past PRS matches we were shooting 6" plates at 293y and hitting them often (not all the time). 8" or even 6" at 300y is not really great accuracy but I have never attempted groups at that distance on paper.

Finally, 400y. Our 400y range is really a few yds less than that. We have a full sized IPSC plate and a KYL plate rack with the largest being 10" the next is 8" and the smallest is 2". I can hit the IPSC plate every time but the 10" and 8" round plates are much much harder and become an act of random luck in my opinion. If you shoot at them long enough, you will hit one every now and again but it is tough.

This weekend, I am taking the Quad to our local range and trying it out past 400y. Hoping to get out to 500y before I run out of up elevation and hold over capacity. We will see.

 

[Williwaw]

The basic cause of the non linear performance is center of gravity offsets in the bullets.

Just repeating that since it is the point that I am questioning. Before I go any further I will say that "I am not a smart man"as per the meme/gif.
It will take me a while to digest all the info so I'll respond in bite size pieces. I had a look at your last link. And thanks for that.

Landy made some relevant comments at the end of this thread in posts #110 and #114 https://forum.accurateshooter.com/threads/22-lr-bullet-sorting.4012117/page-6 (In this thread, the posts by poster "the Stowaway" are well worth reading.)

I couldn't figure out what was meant on the target by indexed and Cg offset as given in clock position. I don't think that is a game breaker. Foremost, I don't see anything here that indicates that Cg irregularities are the principal cause of non-liner dispersion. I don't know the source of the equation but knowing Landy I'm sure it is solid. Nevertheless I don't see distance in the equation and therefore don't see it as proof of non-linear performance.

His post, as I understand it(misunderstand?) seems to say the a projectile with an offset Cg will drift off the ideal trajectory in a linear fashion. Boy, for all the world I expect that thing to spiral around that trajectory. Am I wrong? Can anybody help me?

I'll get back to you as I find the time to review the other links. It is dead still outside and I have an oil change to do before I can go tuning/testing some CenterX.

 

[HuskerP7M8]

The equation in the linked thread was originally developed by Harold Vaughn in his book "Rifle Accuracy Facts".
By indexing, I'm talking about taking where the bullet was drilled to impart the imbalance, and then indexing it in the chamber as if you were looking at a clockface.

Landy

 

[Williwaw]

On pages 169,170 Vaughn says the resultant dispersion is equal to tangential velocity times time of flight. That makes Cg offset a linear contributor to dispersion.

Landy, I'm willing to bet that you've done the math. Did your results conform reasonably to the calculated number?

It looks to me that you got about .35 inches of dispersion when the 'flaw' was about .11 inches from geometric center. That is the furthest possible location. The density contrast between your flaw is also maximal, ie. air vs lead. It seems to me that the effect of inhomogenieties within the lead would cause dispersion of at least an order of magnitude smaller. The largest order dispersion would, I think, be associated with visible flaws (excuse me, I think that is Justin at the door) or out of round/mis-shapen bullets. So now I have to finish rereading Vaughn and research cocentricity gauges.

All good stuff gentleman, I hope the OP has the answers he sought because we've driven this one off the road.

 

[HuskerP7M8]

“On pages 169,170 Vaughn says the resultant dispersion is equal to tangential velocity times time of flight. That makes Cg offset a linear contributor to dispersion.”
If I understand you correctly, that’s true. However, I’m nearly certain it will cause a non-linear growth in dispersion as the distance to the target increases. A lot of ballistic research and testing has convinced me offset is the only thing that fully explains non-linear growth with RF vs linear growth with CF.

“Landy, I'm willing to bet that you've done the math. Did your results conform reasonably to the calculated number?”
Yes I did the math and the results were statistically significant to the 2 sigma level as regards location on the target vs where the equation predicts it will be.

“It looks to me that you got about .35 inches of dispersion when the 'flaw' was about .11 inches from geometric center. That is the furthest possible location. The density contrast between your flaw is also maximal, i.e. air vs lead. It seems to me that the effect of inhomogeneities within the lead would cause dispersion of at least an order of magnitude smaller.”
I don’t know for certain but I think inhomogeneities within the lead are probably very rare in the better grades of ammo.
What I do know is that there have been times in the past where voids in the lead have caused huge problems and they’re invisible to the naked eye. In current years, this problem is also probably very rare.

“The largest order dispersion would, I think, be associated with visible flaws (excuse me, I think that is Justin at the door) or out of round/mis-shapen bullets.”
It’s far too subjective and non-scientific to associate visible flaws with increased dispersion.

I do believe Justin is correct that the appearance is an indicator of general QC but that’s not very helpful for someone like me who wants definitive proof.

The Cg Offset “MUST” be measured before we can correlate for cause and effect.
It’s quite plausible an ugly bullet may have the same offset as a round of Tenex or Midas.

Unfortunately, this offset can’t be measured at the present time either “Dynamically” or “Statically” with RF, as you can do with jacketed CF projectiles. Also, as mentioned earlier in this thread, even if we could measure the offset, it likely changes due to obturation in the chamber and passage thru the bore.

Look at Vaughn’s instrumentation and his examples of Dynamic/Static.

I think I'm done here. Back to your regularly scheduled programming.

Landy

 

[justin amateur]

And after all that discussion, what it comes down to is....
there are only four companies that I have found, that are capable
of producing rimfire ammunition that can be expected to produce consistent accuracy,
Eley, RWS, SK/Lapua and Fiocchi Italia. Their best is intended for use in precision shooting.
All the rest manufacture rimfire ammunition for hunting, offhand and close range shooting,
where the lack of quality control doesn't seriously affect the results.
If it goes bang and clears the barrel, good enough.

 

[Williwaw]

“On pages 169,170 Vaughn says the resultant dispersion is equal to tangential velocity times time of flight. That makes Cg offset a linear contributor to dispersion.”
If I understand you correctly, that’s true. However, I’m nearly certain it will cause a non-linear growth in dispersion as the distance to the target increases. A lot of ballistic research and testing has convinced me offset is the only thing that fully explains non-linear growth with RF vs linear growth with CF.

You understand correctly.

I'm not challenging Vaughn but I have a block to understanding his concept. In order for there to be a perpendicular drift velocity there has to be a causal force. Apparently the barrel resists that force so long as the bullet has yet to exit. After exit, IF the force persisted(and why wouldn't it) the bullets drift velocity would increase, ie.acceleration and non-linear dispersion. So there is something going on at the instant of bullet exit that I don't get.

Look at Vaughn’s instrumentation and his examples of Dynamic/Static.

Will do.

 

[MarkCZ]

I can offer my opinion. Based on my PRS rifle and multiple data sources. Rifle is a Sako Quad Custom with Lilja bbl using a Arken SH4 6-24x FFP MIL optic. Lapua CX ammo. Most outside of the test center data was shot as 5shot groups measured center to center from bipod & rear bag on a bench or prone. In general I consider match accuracy at 50y to be 0.25" c-c with match grade ammo. Some rifles will on occasion do better but few (none) can do better "All day long". The only factory rifles in this class are Annies and Winchester 52's (maybe VuDoo?), I think of VuDoo as more of a factory custom than a true production rifle. To print 1/4" c-c you have to print 12mm edge to edge which is how the Lapua test center measures 10shot groups at 50 & 100 meters (55-110y). 10 shot groups are statistically larger and the 10% longer distance also tends to make them bigger.

For the Sako, the ammo I am currently using printed 10 shots into 17.42mm @ 50m and 34.62mm @ 100m (0.46" and 1.14" c-c). I am usually able to hit a 1" and 1.5" plate prone at 100y. To hit a 1" plate at least on the edge means I must shoot inside of a 1.45" circle. That is about the capability of the Sako. My factory CZ457 VPT is about 1mm larger groups with the same ammo.

I have never made a habit of shooting paper at 200y or further but have on few occasions. At 200y if you can group 2.5" or less you are doing really well. That is what the Sako does in good calm conditions. At these longer ranges the wind becomes much more of a factor as does spin drift. Spin drift is more about hitting the tgt since it is a deviation but more or less constant in one direction. Groups at this range become oblong in the vertical due to ammo inconsistency.

At 200y we shoot a 6" plate (easy) and a 3" plate, less easy. I find both to be very doable with the Sako. We also have shot a bird shaped plate about the size of Robin at 185y and found head shots on it from a bench to be a chip shot. Not sure if that means much.

Next is 300y. We are shooting a 8" plate at that distance. I find it the hardest to get on tgt due to a bunch of factors but once dialed in, I can ring that plate 9 of 10 shots. Wind being a big factor here and am assuming the wind remains steady that long. I can see hits on steel or holes in paper at 300y with this optic and usually the hits are centered well most of the time. In past PRS matches we were shooting 6" plates at 293y and hitting them often (not all the time). 8" or even 6" at 300y is not really great accuracy but I have never attempted groups at that distance on paper.

Finally, 400y. Our 400y range is really a few yds less than that. We have a full sized IPSC plate and a KYL plate rack with the largest being 10" the next is 8" and the smallest is 2". I can hit the IPSC plate every time but the 10" and 8" round plates are much much harder and become an act of random luck in my opinion. If you shoot at them long enough, you will hit one every now and again but it is tough.

This weekend, I am taking the Quad to our local range and trying it out past 400y. Hoping to get out to 500y before I run out of up elevation and hold over capacity. We will see.

I agree with everything in this post. This match accuracy in a nutshell. Just as this post said. You have to take your gun out and see what you can hit.
You do not shoot groups in PRS / NRL. I don't care if you gun / ammo combo can shoot a 1" at 200yds. if you can't hit a 6" target at 200yds, the 1" groups does not do you much good in the dirt.

Mark

 

[300zx_tt]

Seems many shooters here insist that CCI SV performs exceptionally well at 50 yards. They have a very low bar for accuracy.

JBoomhaurer, you changed my question more to your liking. In doing so you succeed in not having to address the reasonable question I did ask. Ducking it after a lot of answers have been given for your (and the OP's) question, suggests you would prefer some things should remain unexamined.

Cci SV at 50 yards seems pretty decent to me? .3” for ammo that’s $35 a brick works for me

 

[littlesister]

And after all that discussion, what it comes down to is....
there are only four companies that I have found, that are capable
of producing rimfire ammunition that can be expected to produce consistent accuracy,
Eley, RWS, SK/Lapua and Fiocchi Italia. Their best is intended for use in precision shooting.
All the rest manufacture rimfire ammunition for hunting, offhand and close range shooting,
where the lack of quality control doesn't seriously affect the results.
If it goes bang and clears the barrel, good en

 

[beetroot]

Cci SV at 50 yards seems pretty decent to me? .3” for ammo that’s $35 a brick works for me

Not sure we can that exception grouping though can we.

In Liam Neesons book on 22lr CofG and drag coefficients, pg 69, he categorically states that CCI SV cannot shoot groups anyone would deem satisfactory, one must buy ammo from 1 of the big 4 manufacturers to stand any chance of shooting a group that even remotely resembles accuracy.

I bet you'll find your shifty ammo throws a few high/low fliers in the 500 brick, which automatically disqualifies it from even an accuracy standard one would even deem "good enough for the price".

 

[littlepod]

Cci SV at 50 yards seems pretty decent to me? .3” for ammo that’s $35 a brick works for me

Was that group right above it, also CCI SV? Is it .3" consistently on multiple groups?

 

[300zx_tt]

Was that group right above it, also CCI SV? Is it .3" consistently on multiple groups?

That was SK high velocity match, unfortunately my CZ doesn’t like it at all.

The CCI SV was typically .3” - .6” had a few that were .7” but I had a 15mph gusty cross breeze. Would I run cci standard in match? Probably not. When I really want to get the Max out of my rifle will I grab the CCI? No. But is it pretty good ammo for $35 a brick? Hell yeah!

 

[justin amateur]

What Would Wilder Say?

 

[JG26_Irish]

I can offer my opinion. Based on my PRS rifle and multiple data sources. Rifle is a Sako Quad Custom with Lilja bbl using a Arken SH4 6-24x FFP MIL optic. Lapua CX ammo.

Finally, 400y. Our 400y range is really a few yds less than that. We have a full sized IPSC plate and a KYL plate rack with the largest being 10" the next is 8" and the smallest is 2". I can hit the IPSC plate every time but the 10" and 8" round plates are much much harder and become an act of random luck in my opinion. If you shoot at them long enough, you will hit one every now and again but it is tough.

This weekend, I am taking the Quad to our local range and trying it out past 400y. Hoping to get out to 500y before I run out of up elevation and hold over capacity. We will see.

I took the Sako out to the big boyz range at our club this weekend. This range has only steel tgts from about 100y out to just under 1000y in irregular increments. Our current steel targets off the standard firing line: 100 yards, 220 Yards, 335 yards, 385 yards, 400 yards, 424 yards, 519 yards, 568 yards, 610 yards, 615 yards, 645 yards, 684 yards, 692 yards.

When we move back to the far position we have steel at: 856 yards, 861 yards, 891 yards, 922 yards, 930 yards. I had no delusions of being able to hit any of these ELR tgts but hoped to get out past the 400y distance with repeatable accuracy and maybe hit one of the 500+ plates. Most of the plates are 12" round.

At 220y (I ranged it 224y), I was on steel with the first shot and followed it up with three more. Easy peasy, right? Moved out to 335y (I ranged it 334), and it took one miss high left, down 1/10th mil, right 2/10mil... Impact!. Followed this with 4 more clean impacts on the plate. It was gusty this day but seemed to be steady right to left most of the time and was not affecting me too much. My Strelok Pro model for this rifle is still not perfect. Plus I have to remember to input ambient temp data every time or it is off just enough to be a problem at the longer ranges.

Next was the 12" plate at 424y (I ranged it the same). Took two shots but then was able to hit it three in a row until the next miss which could have been wind or ammo (never the shooter ). Next, I pushed out to 568y (I ranged it 560y). I run out of up adjustment at 17 mils. So, I was holding 6.5 or 7mils over at 424. When I went out to the 560y distance, I think I had a brain fart that only became clear to me as I was writing this post. Here's the deal, to quote another senile old bastid...

Strelok calls for 36.6mils up at 560y for my rifle/ammo combo. I dialed the 17mils in the scope earlier on the 424y tgt. So, all I had to do was hold over for the difference of 19.5 or 20 mils right? I have developed a habit of keeping range notes at all practice and match sessions. It helps me to remember which ammo worked best in which rifle and what conditions I was shooting in, etc. Looking back at my notes for this session I found the smoking brain fart that cause me to miss the 560y tgt for all my shots. Those of you who have the SH4 Mil scope probably already know that it cannot hold over 20mils and still see the tgt... Ooops. My notes say I held 10mils over plus the 17 I had previously dialed.... Double Ooops. My holdover was not enough by 10mils. At that distance my rifle's shots drop about 739 inches, or 61.5 feet. That is about 20inches per mil. So, by not holding the extra 10mils, my bullets were 202 inches low or almost 17 feet low. Yeah, I could not even spot my misses to make adjustments, lol. Epic fail. Since this rifle, optic, ammo combo is limited to about 17 dialed plus 15 hold over mils, I cannot hope to shot past about 515y without changing the mount or going to faster ammo.

I wish I have figured this out sooner, while at the range, but that is why we practice to learn and get better. At 500y, I think I would have needed a much larger tgt than the 12" plate available at that time. Now, I want to return to the range. If I dial 17 and hold over 15 mils and then aim12 feet over the tgt, I could just about lob one into that 560y steel plate, lol.

 

[Milo 2.5]

Next was the 12" plate at 424y (I ranged it the same). Took two shots but then was able to hit it three in a row until the next miss which could have been wind or ammo (never the shooter ). Next, I pushed out to 568y (I ranged it 560y). I run out of up adjustment at 17 mils. So, I was holding 6.5 or 7mils over at 424. When I went out to the 560y distance, I think I had a brain fart that only became clear to me as I was writing this post. Here's the deal, to quote another senile old bastid...

Strelok calls for 36.6mils up at 560y for my rifle/ammo combo. I dialed the 17mils in the scope earlier on the 424y tgt. So, all I had to do was hold over for the difference of 19.5 or 20 mils right? I have developed a habit of keeping range notes at all practice and match sessions. It helps me to remember which ammo worked best in which rifle and what conditions I was shooting in, etc. Looking back at my notes for this session I found the smoking brain fart that cause me to miss the 560y tgt for all my shots. Those of you who have the SH4 Mil scope probably already know that it cannot hold over 20mils and still see the tgt... Ooops. My notes say I held 10mils over plus the 17 I had previously dialed.... Double Ooops. My holdover was not enough by 10mils. At that distance my rifle's shots drop about 739 inches, or 61.5 feet. That is about 20inches per mil. So, by not holding the extra 10mils, my bullets were 202 inches low or almost 17 feet low. Yeah, I could not even spot my misses to make adjustments, lol. Epic fail. Since this rifle, optic, ammo combo is limited to about 17 dialed plus 15 hold over mils, I cannot hope to shot past about 515y without changing the mount or going to faster ammo.

I wish I have figured this out sooner, while at the range, but that is why we practice to learn and get better. At 500y, I think I would have needed a much larger tgt than the 12" plate available at that time. Now, I want to return to the range. If I dial 17 and hold over 15 mils and then aim12 feet over the tgt, I could just about lob one into that 560y steel plate, lol.

We set a 12" circle at 600 a week and a half ago and gave it a run. I was able to dial all but around 1 mil of the dope, around 35 mils, 4700ft ASL. We set the plate in the middle of the trail, no berm, spotting shortcomings did not help, and the bulk of our shots were high we just didn't see that. Our hit pct sucked, way low, but our sample size was high, so we got points for that. 12" plate at 500 was easy that day.

 

[obx22]

Sure, Ken. Obviously, I didn't develop this idea. But it's not a new one.

For more recent explanations of the role of Cg offset in .22LR non linear performance, you may recall posts by Landy (HuskerP7M8), a respected poster here and elsewhere. I refer to his posts with regard to the relationship between Cg offset and non linear pereformance. As you may know, Landy tests extensively in his own testing tunnel and conducts considerable statistical analysis of .22LR results, which inform his observations on the causes of .22LR non linear performance. I hope I haven't misrepresented anything he's said.

After MV variation, which is responsible for vertical spread and is inevitable in even the best match ammo, the next most important cause of non linear growth is Cg offset. Landy writes about it matter-of-factly, as though it's not a factor that's contentious in any way. Since velocity variation is not the only cause of shot dispersion, it explains why shot location at one distance doesn't always predict shot location further out. (Heel irregularity would be another, but we can restrict the discussion to bullets that are otherwise not flawed.)

For some elaboration, below are links to some of Landy's posts. He may well have other or more expansive posts, but these are the ones I could easily find. Of course, others may have also studied and remarked on Cg offset in .22LR.

See, for example post #17 https://www.rimfirecentral.com/threads/distance-vs-group-size-multiplier.525672/
More details are offered here in post #15 https://www.rimfirecentral.com/threads/a-question-about-lead-bullets.1060730/
See also post #13 https://www.rimfireaccuracy.com/Forum/index.php?threads/ammo-testing-at-25-yards.28412/
Landy made some relevant comments at the end of this thread in posts #110 and #114 https://forum.accurateshooter.com/threads/22-lr-bullet-sorting.4012117/page-6 (In this thread, the posts by poster "the Stowaway" are well worth reading.)

This Cg offset mentioned prompts the following questions:
1. Can rifling style help cancel out this offset?
2. If question #1 were valid, do we really pay enough attention to the bore at the muzzle (vs the crown)?

Referring on question #1 to say 5 groove (odd number) which obviously doesn’t have lands opposing each other vs say a 6 groove (even, duh) which does.
Does one rifling type produce better Cg projectiles than any other (haven’t heard of Marlin Microgroove barrels in benchrest).

To expound on #2, we work to ensure the crown is concentric, and cut to the angle/flavor of the day, but do we ever measure/check the lands-grooves at this point for concentricity?
I would think (dangerous) that the swaging effect on the projectile from the bore would largely cancel out a lot of concentricity errors on the projectile, but could induce terrible ones if say a land or groove is different from it’s fellows at the muzzle?

 

[RTH1800]

I’ll add a few examples shot with Eley Match and Eley Tenex ammo. First one is 200 yard group with no allowance for wind. I was gathering data for a custom reticule in my Unertl. Note lack of vertical dispersion. Second is a 100 yard group with Tenex shot on a calm evening. Next are some data verification groups shot on a calm evening prior to a squirrel hunt. They were shot on one target at the ranges listed and were the only shots fired. @justin amateur will call them selected groups or “wallet groups”. I do not agree. In calm conditions this is how the rifle shoots. Justin needs to get a good 52 C and lose some of that negativity.
All groups shot prone or sitting

with tight sling.

 

[justin amateur]

Right....like a 52C shows up regularly in my lgs.


My problem isn't the rifle, it's just the cheap ammunition.
Folks keep telling me submoa all day long with the cheap stuff,
but it ain't happening.
Last bit of foolishness was 17hm2.
Squirrel head shots at 100 yards, no problem I was told.
Try it, you'll like it they said. So I did.
2 moa varminting cartridges made by CCI.
I consider it an educational expense.

 

[Gleedus]

Very entertaining.....
I enjoy how each person strong advocates for their view. I could do the same.
But seriously this had gotten off topic. How be it onto a very interesting target.
For PRS/NRL my standards are very simple. Shoot a rifle kraft drill use a ammo that shoots a smaller group then that and your good to go. As skill level increases so will your ammo requirements.
I remember when I started a 8" square at 200 had its challenges. Cci sv was good enough. But time moves on and now the ammo "budget" doesnt reach as far anymore..

 

[Emerson0311]

Very entertaining.....
I enjoy how each person strong advocates for their view. I could do the same.
But seriously this had gotten off topic. How be it onto a very interesting target.
For PRS/NRL my standards are very simple. Shoot a rifle kraft drill use a ammo that shoots a smaller group then that and your good to go. As skill level increases so will your ammo requirements.
I remember when I started a 8" square at 200 had its challenges. Cci sv was good enough. But time moves on and now the ammo "budget" doesnt reach as far anymore..

This is my experience also. Lots of small group bench shooting is ballistic masterbation for the Rimfire PRS competitor. When my positional groups get small enough to compete with my bench groups, practice ammo needs an upgrade. Custom rifle accuracy is not the problem. Shooter ability positionally is the issue, especially POI shifts due to bad position building. Getting tired or distracted and still attempting to shoot consistently simulates match day quite well. 1 1/2” positional groups centered on the POA at 100 is the goal for me. Farther out, the issue is not my position, it’s the vagaries of 22LR ammo and wind effects. Getting up off the bench and “ “holding” for solid 2.5MOA-ish size groups at 200 centered on the POA is not the biggest challenge; the velocity induced vertical spread and wind induced POI shifts are a bigger problem for me at that range and beyond.

 

[Gleedus]

This is my experience also. Lots of small group bench shooting is ballistic masterbation for the Rimfire PRS competitor. When my positional groups get small enough to compete with my bench groups, practice ammo needs an upgrade. Custom rifle accuracy is not the problem. Shooter ability positionally is the issue, especially POI shifts due to bad position building. Getting tired or distracted and still attempting to shoot consistently simulates match day quite well. 1 1/2” positional groups centered on the POA at 100 is the goal for me. Farther out, the issue is not my position, it’s the vagaries of 22LR ammo and wind effects. Getting up off the bench and “ “holding” for solid 2.5MOA-ish size groups at 200 centered on the POA is not the biggest challenge; the velocity induced vertical spread and wind induced POI shifts are a bigger problem for me at that range and beyond.

Yupper! At some point your positional skill will be better in MOA then your groups at 200 which I think your well past watching your progress. I'm thinking your ready for a step up in ammo for matches.
As you know I do all my positional training at 50 instead of 100 but either way once your running a consistent 1 moa +/- POA then ammo will help the far stuff.

 

[Manning5R]

I've settled on 75-80 yards for positional practice. Far enough that position and trigger press issues show up easily, and close enough the ammo isn't a problem. "...small group bench shooting is ballistic masterbation..", LOL!

 

[Emerson0311]

Yupper! At some point your positional skill will be better in MOA then your groups at 200 which I think your well past watching your progress. I'm thinking your ready for a step up in ammo for matches.
As you know I do all my positional training at 50 instead of 100 but either way once your running a consistent 1 moa +/- POA then ammo will help the far stuff.

I’ve got budget challenges and 1 1/2 cases of SKRM/SKLRM so that will last until the spring I hope. I want some Eley Match and an EPS chamber to shoot it in, but I’ll probably buy fuel instead.

 

[Emerson0311]

I've settled on 75-80 yards for positional practice. Far enough that position and trigger press issues show up easily, and close enough the ammo isn't a problem. "...small group bench shooting is ballistic masterbation..", LOL!

Only for the PRS stuff though. I’ve watched some amazing BR shooters, but that’s a whole nother rabbit hole.

 

[mikeshaw2]

Sorry, I was being lazy. But as Justin said I was agreeing with his feelings of top level accuracy is. If a rifle and ammo combination can fairly consistently hold half MOA or less at 50 yards and around 3/4 MOA at 100 yards your getting there. But the hard part is how you define consistency…

Give me enough time to get set, get the breathing right, etc and I can do that all day long

Put me next to an RO saying 'shooter ready?' and when the beep goes off, all heck breaks loose skill-wise. I'm working my way to being better, but it's been a tough-fought series of lessons.

My local indoor range has their targets on flip timers so you can mimic the pressure of being on the clock, but there's only so much you can do for multiple distance and positions. I'm constantly amazed at how quickly *my* 90sec goes and how long it takes everyone else's

M