I just added Part 3 of my Science of Recoil series on YouTube. I'm posting it here because it features my 300 PRC. Aside from one very pronounced flyer (grumble), it performed for the camera!
300 PRC update
- Thread starter DAVETOOLEY
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@Rocketmandb One of the most authentic and precise depictions of a PSI Meter I've seen on YouTube 
Enjoyed it man. Keep the videos coming.
And at 500 yards that wasn't a flyer...that was my normal shooting
Enjoyed it man. Keep the videos coming.And at 500 yards that wasn't a flyer...that was my normal shooting
@Rocketmandb One of the most authentic and precise depictions of a PSI Meter I've seen on YouTube
Precision at its best!
Did you uniform the necks prior to measuring the thickness?
I measured the neck thickness of the 50 pieces of 300 PRC RCC brass. I was able to make one sometimes two measurements around the neck of each piece of brass. The issue I encountered was a slight bow in the neck. The flat of the Mitutoyo ball micrometer was not making full contact with the neck wall .. I was able to see light between the brass and the Mitutoyo. Here's an illustration:
Of the thinnest measured neck thickness measurements the maximum was 0.0159" and minimum 0.0124". The average of these measurements of 50 pieces was 0.0145".
For comparison, I measured some Lapua brass (of a different cartridge) which had been fired 2-3 times and neck sized with a Lee collet neck only die. The necks were consistent in shape (not a surprise really) and I was able to make 4 measurements along the neck cylinder.
I am working towards sacrificing a piece for the AZTEC and I am so far not sure the neck thickness measurements I'm able to make are useful to determine which piece is the best representation of the group.
Will the 300PRC reliably push 225gr ELD-Ms to 2900~2950 out of a 24" tube? Or is it going to just depend on the barrel. Came across the 30 sherman which is the 300 PRC improved essentially and can be fireformed with factory hornady match ammo.
Left and right are 30 sherman, middle is the PRC.
Also anyone considered a 1-7 twist with the 225gr ELD M? or is that just too fast?
Left and right are 30 sherman, middle is the PRC.
Also anyone considered a 1-7 twist with the 225gr ELD M? or is that just too fast?
Sportsman's Warehouse has RL-26 in stock.
www.sportsmans.com
Alliant RL-26 Smokeless Powder - 8lb Keg
Alliant RL-26 Smokeless Powder - 8lb Keg
www.sportsmans.com
Sportsman's Warehouse has RL-26 in stock.
Alliant RL-26 Smokeless Powder - 8lb Keg
Alliant RL-26 Smokeless Powder - 8lb Keg
So scarce they don't even have a proper picture of it....if they still have some in stock Wednesday when I have a day off..>I may run down and pick some up in person.
Already out of stock near me. Thought i could ship it to southaven. Damn i got 5lbs left but magnums eat this crap up.
Just have to find the store that's in stock. Looks like AZ, NV, CA have some. Didnt check past those states..
i can’t speak to speeds as I don’t own one yet, but if you wanted 50-100 fps over a prc I personally would just do a 30 nosler instead of dealing with fire forming brass and custom dies.
I really don't have a valid answer except that i'm a stickler for maximizing efficiency. I also don't mind fire forming or custom dies. Especially since i can fireform with Hornady ammo. I was just looking at the 225gr ELD-M @ 2900 vs my current 7 SS load of the 180gr ELD-M @ 2900 and was pretty shocked to see it on the heels of the 225gr. Guess i could go that route wonder how the long 225~250s would fair with the 30 nosler.
i don't think the 30 SM gives up anything to the nosler
I should have a Sherman done soon?! It’s been a year or so in the making just waiting on parts but I think it’s finally close to ready? Running 1-8 so it should be good for the heavys.
Gray Sloan @ Swift Creek Rifles in NC. We were originally waiting on a prc reamer first but he was able to get a Sherman reamer than the prc. I think he rented it.
I have looked into the 30 Sherman mag. What velocity increase are you finding? 125-150 FPS?
On primers...I used the Federal GM210M's... Why?.,..because I had a crap ton of them already...and was more worried about powders and bullets than primers. They shoot great. I haven't seen any need to go to a GM215M Magnum primer at all.
On the 230 A-Tips and H1k.....watch your pressures with that powder/bullet combo....well...if you want to hot rod it like I do...that's why I use N565.
On the 230 A-Tips and H1k.....watch your pressures with that powder/bullet combo....well...if you want to hot rod it like I do...that's why I use N565.
I learned along time ago about pushing for speed. I use to shoot a .257 wm for pdogs.?
I'll bo looking for a load in the 2800 to 2850 fps area.
FWIW win mag primers were the magic for that.
I'm going to grab some 565 and 225 eldm next time I'm in the city.
I'll bo looking for a load in the 2800 to 2850 fps area.
FWIW win mag primers were the magic for that.
I'm going to grab some 565 and 225 eldm next time I'm in the city.
30 sherman magnum
This was formally the 300 PRC S.I. for those who missed it. I got out a couple days ago to do some more testing and the mirage shooting over the bright snow was terrible so I couldn't really accomplish as much as I wanted to. I did get some velocities and enough data to make another run on a...
I would think neck and neck with the 30 nosler here is Rich's thread.
Reliably at under 65,000psi? Probably not in a 24". If you'd step it up to 28-30" or want to shorten brass/barrel life at your own peril, then 2900-2950 is certainly attainable. My 30" barrel is doing 2940 about a grain under max published load data.
Why would you want to go 7 twist?
1:9 will stabilize a 250gr A-tip. SAAMI spec is a 1:8.5. I don't see any real benefit, and you're just edging closer to the line of spinning bullets apart with a 1:7. Unless you have long copper solids in mind I'd stick 1:8-1:9.
Consider what you're doing with a 7 twist at 2950fps.
2950 ft/s * 12 in/ft / 7 in/rotation * 60 s/min = 303,428 rpm
Riding the danger zone of what a bullet will take.
I saw this pic that said the 225gr ELD-M BC was higher with a 1-7 twist but i honestly knew nothing about that which is why i asked. Thank you for clarifying. I'm pretty set on 30 Sherman at this point. Would probably be pushing just like i am with the 7 SS. Though barrel length is of concern just because i run cans and don't want a javelin. That said could go 26" and grab a resonator K as intended at 5" that's shorter than my 24" 7 SS with the hybrid at the moment.
Probably Hornady published dopler data. CD does decrease (BC increase) with faster spin rates. I just get worried when velocities approach or exceed 3k and twist rates get faster than a 1:8. Seen some failures in smaller caliber stuff and most bullet manufacturers specifically call out the 300k rpm number for thin jacketed match/varmint bullets.
Yup i thought i posted that pic in that post. But it was showing various bullets BC at faster twist rates and it got me to thinking.
While I'm here, and for those curious... I lost count of how many rounds exactly I have on my 31" Bartlein. I went back and tallied up (conservatively, I think there could be another 150ish rounds on this from various load dev/testing that I'm leaving out) all the shots and I'm at ~1100 rounds.
I got around to tallying up the round count because the rifle recently started giving me .6-.9 MOA 5-shot groups where it was a .3-.6 MOA ordeal before for 5 shots. My last long-range range trip I was still able to tag the 1650yd torso plate consistently, but struggled out around 2000yd. I've since tried about 50 rounds of playing around to try to tighten things up and haven't made much progress. Just throwing it out there as a data point. I bore scoped the barrel and it looks about like you'd expect for a magnum with 1100 rounds on it. I wasn't very nice to it at all, in terms of rate of fire. I did a lot of 10-15 shot strings that got things pretty hot. Velocity data is still producing 6-10fps SD's, and is maybe 20fps slower than when I originally worked up my loads.
I think because this is purely an ELR rifle I'm going to order up a new pipe and retire this one. It's still very usable within 1500 but not giving the sharp edge I'd like.
I got around to tallying up the round count because the rifle recently started giving me .6-.9 MOA 5-shot groups where it was a .3-.6 MOA ordeal before for 5 shots. My last long-range range trip I was still able to tag the 1650yd torso plate consistently, but struggled out around 2000yd. I've since tried about 50 rounds of playing around to try to tighten things up and haven't made much progress. Just throwing it out there as a data point. I bore scoped the barrel and it looks about like you'd expect for a magnum with 1100 rounds on it. I wasn't very nice to it at all, in terms of rate of fire. I did a lot of 10-15 shot strings that got things pretty hot. Velocity data is still producing 6-10fps SD's, and is maybe 20fps slower than when I originally worked up my loads.
I think because this is purely an ELR rifle I'm going to order up a new pipe and retire this one. It's still very usable within 1500 but not giving the sharp edge I'd like.
What bushing size are you guys running? I've been using .334. Maybe I need to check some more neck tension, accuracy has been great with my current load work ups, just curious
Sportsman's Warehouse has RL-26 in stock.
Alliant RL-26 Smokeless Powder - 8lb Keg
Alliant RL-26 Smokeless Powder - 8lb Keg
I got a notice H1000 will soon be available as well.
Similar speeds and BC
That’s the beauty of the 7mm’s
I’ve definitely had some blow up issues with the ELDM’s in 6.5 and 7mm.
my 7 saum launching 180’s at 2930 with a 1-8 Is blowing up a somewhat disturbing percentage but I keep running them because the ones that make it are kicking ass.
you can literally hear a difference in the ones that don’t make it.
I’m going to start out with 230 Berger’s. Slightly less BC than the 225 ELD M. But they kill the hell out of game.
That's what I'm using and I like them quite a bit.
I’m sure I’ve read it somewhere but what velocity and barrel length you reporting?
So, I'm an odd one out here as I'm prepped/fire-formed RWS 8x68S brass. My current load is 71.8 gr of RL26 and it's getting me 2825 fps through a 28" barrel. Note that the RWS is thicker so has a lower volume, which means less powder required. I have pushed these into the upper 2900s without pressure signs, but I'm getting the best accuracy a lot lower.
Try CCI200’s. They dropped my SD to 6.7-10. Fed210M’s the lowest I could get was 13 for SD. This is out of virgin Hornady brass. Usually once fired brass you might be able to get the SD to drop a smidgin more.
I’ve shot 225 ELD’s and 230SMK out to a 1k yards. Bullets are coming out at 2900fps. 1-9 twist barrel, 5R rifling. Barrel length is 32”. That’s a good working every day load. I’m not stepping on it. Gun pretty much held 1/4moa for vertical and I can easily clean a F class target. Rifle is set up for F Open. The Hornady’s shot about a 1/8 to 1/4moa flatter than the SMK. Bullets where hitting the target right about 1900fps at a 1k yards.
Next powder to try is RL26.
I’ve shot the 230ATIPs but only out to 430 yards so far.
Later, Frank
Bartlein Barrels
32" Dang Frank, you got someone to carry that thing around for you? My Bartlein barrel shoots wonderfully.... 28" 1-9tw
My Bartlein barrel shoots wonderfully.... 28" 1-9tw
32" Dang Frank, you got someone to carry that thing around for you?
I'm probably going to cut 2" off the muzzle end. I don't think the extra 2" is giving me really anymore per say velocity wise but just having hard time pulling it as it shoots so well. It's like...why?
I know for sure the next barrel will only be a 30" finish length.
Here is a pic of the rifle. It weighs just under the 22# limit for F Open. The action is a Barnard Model PL. The barrel has a 1.350" breech diameter x 5" and str. tapers to 1.125" at the muzzle.
Later, Frank
Attachments
@Frank Green Beautimous....it almost appears that the bolt is made from the same piece of steel as the barrel. Now you are going to have all the lefty shooters on the boards jealous.
Yep it is a lefty!!!!
With a custom bolt handle and knob that we made at work. The handle is patterned after the one my friend John H. use to make for the Barnard's and RPA type actions. He had one left that wasn't finished and gave it to me to use to copy. I have one of his originals on my other one. The factory Barnard handles are aluminum. My handle the shaft is SS (yes made out of gun barrel material) and the knob itself is made out of aluminum that I polished. The handle on the floor is one piece SS.
Later, Frank
Attachments
Hm @Frank Green I am thinking about doing a 1:8 to be able to launch the 230/250 A-tips... it seems the math shows I wouldn't spin the 225 EDMS/230 Bergers to fast so it should work for all of the above? Just wanted to see what you thought.
Placed an deposit my left action so it's happening... Going to need to order a barrel from you guys soon.
Placed an deposit my left action so it's happening... Going to need to order a barrel from you guys soon.
Only reason to faster than a 9 twist is if you want to shoot the250's. Then you need a 1-8.5. I'd lean towards a 1-8.25.
If I remember correctly the SMK need like a 9.26 min. twist or like a 9.52. Can't remember which. Anyways that's why I went 9. They hammer thru my gun. The 225's will fly out of a 10 twist barrel but to me on ragged edge. A little faster on those won't hurt ya either.
It's my second Barnard if that tells you anything. It's tough to beat. My first one is a standard Model P. They have excellent triggers that can be used as a two stage or single stage. Mine is set as a two stage and the second stage breaks at 15oz to 1# as close as I can measure.
The stock is a Manners F class stock in carbon fiber.
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