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300 PRC update

There is none, at least in my samples and chamber.

I measured a few...and gave up....didn't really see a reason to continue. I've shot 5 of Hornady and 5 of the new Lapua in the same 10shot string and saw an SD of 6 and an ES of 17 when mixing both brass....same powder load, same bullet...same everything else. The Lapua showed to be heavier on average.
 
Good info guys. Any difference w ADG vs Hornady? My brass should be here Tuesday.
 
I found a measurable (on paper and chrono) difference between ADG and Hornady....reduce charge for ADG and work up.
 
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If you are shooting 375 and 416s you really don't have a choice but solids. And guys are winning ELR comps with them, mostly Cutting Edge solids as they radar very well and seem to shoot well. The CE Lazers have a lower BC for solids and i think that has to do with why they shoot so consistent. You really don't need the highest bc or muzzle or muzzle velocity to do well. Just raw consistency in the gun ammo and you as the shooter. A jacketed bullet is usually half the cost or cheaper, so the extra practice you can get for the same $$ is probably worth it shooting a bullet with a slightly lower BC.

Litz posted a bunch of info from the Knobs creek ELR 2020 and 2021 matches, they radar-ed almost everyone's gun. Looks like only one PVA bullet made it into the testing, i thought it was more. But PVA (Josh), also designed the Warren tool solids I believe, and they were the bottom two in consistency. Litz has commented that no matter the twist rate they can't get the warren tool to be consistent.

View attachment 7624316
Interesting

In my rifles I get just as good vertical with badlands as the Berger LRHT.
Except with a .506 G7 at a bit over 3000 the badlands shoots a lot flatter.
No issues with subsonic performance with either as well.
 
Is anybody running 220 SMKs in this, or is it mainly 212 and 225 ELDs and 215 and 230 Hybrids?
 
Is anybody running 220 SMKs in this, or is it mainly 212 and 225 ELDs and 215 and 230 Hybrids?
Running 220gr scenars with Hornady brass, 215m primers seated 0.015" off the lands with 77.5gr IMR7977 comfortably at 2940fps 1/2moa consistently now that I've figured out my accuracy issues.. as always use caution, this is my load workup with my rifle.
 
Running Berger 220 w n570 in ADG brass. Hit 3099 FPS from 28 inch while fire forming to 30 SM. Loaded same charge weight and dropped 10 FPS. Shot it at 1k and a mile Friday. Low ES SD, may not even mess w the load. Put 3 on the same spot at 1k than went 3 for 3 at 1 mile on 18 inch round plate.
 
Are any of you guys worried running such low fill ratios with RL26?
 
Yes! I bailed on 26 as I got hang fires in cold weather no matter what primer I tried. And I tried em all! Not every round and maybe not perceived by some, but I noticed it. My buddy shooting a 300WM running a different lot# of 26 had the same issues. Maybe it was the Altitude, maybe the cold, but switched powders with a better fill ratio and it went away. I see a lot of guys getting good results with it, just not me.
 
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Are any of you guys worried running such low fill ratios with RL26?

I haven't had a problem in the 800 rounds I am in 300PRC so far.

But I haven't shot anything colder then 55F probably.
 
Yes! I bailed on 26 as I got hang fires in cold weather no matter what primer I tried. And I tried em all! Not every round and maybe not perceived by some, but I noticed it. My buddy shooting a 300WM running a different lot# of 26 had the same issues. Maybe it was the Altitude, maybe the cold, but switched powders with a better fill ratio and it went away. I see a lot of guys getting good results with it, just not me.
Interesting. I am in a pretty cold spot, so maybe I ought to start out with H1000 instead. I don't think I can take fucking with N570 in my autotrickler this week.
 
Are any of you guys worried running such low fill ratios with RL26?
Berger had worries about that when I talked to them - they specifically recommended against RE26 for the 230s and 245s because of the fill ratio.

I did shoot some 210s with 26 and I got up to 2990 before I got pressure signs on a 26” barrel jammed into the lands. I’ve since switched to N570 and let the RE26 rip in my Creedmoor (I’m getting crazy velocities, another 150fps with no pressure compared to H4350).
 
I've shot 800 Berger 245's with RL-26 and about 1200 230 A-Tips with RL-26 in my 300PRC in two different barrels. I've shot from 10F to 95F temps.....with Fed 210M's..and then switched to Fed 215M's. What kind of low fill ratio are you talking about? My fill is at...or damn near the start of the bottle neck with the boat tail sticking down below the neck/shoulder junction....there isn't much shake to the powder if I salt shaker the brass after loading.

This is a new topic for me....haven't heard of any problems out there in the real world on this issue. But...by all means...leave the RL-26 alone and go buy something else....while you are at it...don't buy any 245 EOLs either....leave them for me.

*Edit* Also, last month when shooting at Black Bear in VA....we were shooting down hill at what sometimes in a -15* slope....and never experienced anything negative.
 
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Just sold my 16lbs to my buddy for his 6.5PRC. Like I said, others have had good luck with it, not me or my buddy. Real world experience.
 
I've shot 800 Berger 245's with RL-26 and about 1200 230 A-Tips with RL-26 in my 300PRC in two different barrels. I've shot from 10F to 95F temps.....with Fed 210M's..and then switched to Fed 215M's. What kind of low fill ratio are you talking about? My fill is at...or damn near the start of the bottle neck with the boat tail sticking down below the neck/shoulder junction....there isn't much shake to the powder if I salt shaker the brass after loading.

This is a new topic for me....haven't heard of any problems out there in the real world on this issue. But...by all means...leave the RL-26 alone and go buy something else....while you are at it...don't buy any 245 EOLs either....leave them for me.

*Edit* Also, last month when shooting at Black Bear in VA....we were shooting down hill at what sometimes in a -15* slope....and never experienced anything negative.
Thanks. I'm really trying to get as close as I can without doing too much, since I don't want to waste components I do have. I figure if I can avoid the bigger mistakes, I should be good.
 
I've shot 800 Berger 245's with RL-26 and about 1200 230 A-Tips with RL-26 in my 300PRC in two different barrels. I've shot from 10F to 95F temps.....with Fed 210M's..and then switched to Fed 215M's. What kind of low fill ratio are you talking about? My fill is at...or damn near the start of the bottle neck with the boat tail sticking down below the neck/shoulder junction....there isn't much shake to the powder if I salt shaker the brass after loading.

This is a new topic for me....haven't heard of any problems out there in the real world on this issue. But...by all means...leave the RL-26 alone and go buy something else....while you are at it...don't buy any 245 EOLs either....leave them for me.

*Edit* Also, last month when shooting at Black Bear in VA....we were shooting down hill at what sometimes in a -15* slope....and never experienced anything negative.
I was wondering what your COAL was with your 245 Bergers, also what twist you got on your barrel. I got a bunch of 245s and should have my rifle in 3 months, looking forward to trying the 245s if powder ever comes available. Thanks!
 
I was wondering what your COAL was with your 245 Bergers, also what twist you got on your barrel. I got a bunch of 245s and should have my rifle in 3 months, looking forward to trying the 245s if powder ever comes available. Thanks!

I run two COAL's..... 1. is 20 thou off the inside dimensions of my magazine wall....so I can reliably feed from the magazine. 2. is...I hold the bullet up to the brass...and you see the bearing surface to boat tail junction?.....then hold up your brass....see the neck/shoulder junction?.....line those two up with seating depth...and that's where the magic happens. On the 230 and 205 A-Tips...and the 245 EOLs...this means they are too long to be mag feedable....but for shooing ELR and benchrest or F-Class...or belly matches....PERFECT!

You may have to move yours 3-6 thou here and there...but those measurements are close for multiple rifles I've reloaded for.
 
I run two COAL's..... 1. is 20 thou off the inside dimensions of my magazine wall....so I can reliably feed from the magazine. 2. is...I hold the bullet up to the brass...and you see the bearing surface to boat tail junction?.....then hold up your brass....see the neck/shoulder junction?.....line those two up with seating depth...and that's where the magic happens. On the 230 and 205 A-Tips...and the 245 EOLs...this means they are too long to be mag feedable....but for shooing ELR and benchrest or F-Class...or belly matches....PERFECT!

You may have to move yours 3-6 thou here and there...but those measurements are close for multiple rifles I've reloaded for.
The second is how I did mine for my 215s. Let's hope they shoot.
 
So, my ladder test struck me as a bit odd. The good news is that the last nine of the ten rounds were exactly the same POI. Less than .5 inches. The lowest charge was same windage, about 3/4 inch up. The weird news is that they were absolutely humming. I set the ladder to start around 2800 and go to 2950 or so according to QL and Gordons. The first round came out at 3009. This is with 215s. I shot 5 rounds, then loaded up 5 at lower charges to finish off. The lowest was still 2973. Only pressure signs are a tiny bit of primer flow back, but it is in an AXMC, so this is par for the course. I have a big flat spot at 2990, so I guess I will see what that looks like SD wise. These are definitely running hotter than I imagined. This ends up at 76.9 grains of RL26 with 215 hybrids.

Any comments or ideas please let me know.
 
Yes! I bailed on 26 as I got hang fires in cold weather no matter what primer I tried. And I tried em all! Not every round and maybe not perceived by some, but I noticed it. My buddy shooting a 300WM running a different lot# of 26 had the same issues. Maybe it was the Altitude, maybe the cold, but switched powders with a better fill ratio and it went away. I see a lot of guys getting good results with it, just not me.
Do you recall the charge weight, bullet, and coal?
 
So, my ladder test struck me as a bit odd. The good news is that the last nine of the ten rounds were exactly the same POI. Less than .5 inches. The lowest charge was same windage, about 3/4 inch up. The weird news is that they were absolutely humming. I set the ladder to start around 2800 and go to 2950 or so according to QL and Gordons. The first round came out at 3009. This is with 215s. I shot 5 rounds, then loaded up 5 at lower charges to finish off. The lowest was still 2973. Only pressure signs are a tiny bit of primer flow back, but it is in an AXMC, so this is par for the course. I have a big flat spot at 2990, so I guess I will see what that looks like SD wise. These are definitely running hotter than I imagined. This ends up at 76.9 grains of RL26 with 215 hybrids.

Any comments or ideas please let me know.
Bartlein barrel? My sons rifle we just built has a fast barrel. Hit 3100 FPS w Berger 220 on low level fire forming load. Almost called Berger to tell them their load data is wrong 😂
 
Bartlein barrel? My sons rifle we just built has a fast barrel. Hit 3100 FPS w Berger 220 on low level fire forming load. Almost called Berger to tell them their load data is wrong 😂
Hawk Hill, but now that you mention it, I have four barrels from him, that he has also chambered, and every one is smoking fast. This barrel is nearly 100 fps faster than standard with factory ammo as well.
 
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I've had quite a few issues come up with my 300PRC during load development. So starting out I had just under a 1 minute rifle which really pissed me off. Granted I was shooting factory ammo for the brass. So when I switched to load development I found my powder charges. I'm using H1000, RL26 and IMR7977. I'm down to a pound of RL26 now so am usingtheothers. I did my seating depth test. I was shooting at 200 yards and still couldn't get it to group worth a shit. If I was lucky to have a group under 1 minute. I tried multiple powders with multiple bullets and was racking up the round count with no answers. I've ran 220gr ELDX, 220gr MK's, 220gr scenars, 200gr ELDX and 225gr ELDM's. I was working with and talking to my smith during all of this and we were about to recrown or rechamber my barrel. I'm running a 28" 9 twist M24 SS proof barrel on an Archimedes action. I couldn't find anything wrong with the crown or chamber. I decided to try one more thing which was to pull the muzzle brake and see what it changed. I loaded up generic loads with.. 2x Hornady brass, 215m primers, 220gr ELDX with 0.020" jump pushed by 74.5gr RL26 and another with 220gr scenars 0.020" jump pushed by 74.5gr RL26.
The 220gr ELDX with the brake shot about 1.5moa and without shot 0.750moa. The 220gr scenars shot right at 1 minute with the muzzle brake and shot about 0.500moa without. All shot data was taken at 200 yards. Another thing to note is I was getting single digit ES and SD's. The concentricity was checked,, bullets and cases were weight sorted for the above rounds. See attached pictures.
220gr ELDX...edited from 225gr ELDM's
20210501_191142.jpg

220gr scenars
20210501_193636.jpg

I was surprised and relieved that I had found the issue. I purchased a Area 419 Sidewinder muzzle brake and I now have a shooter. My rifles only problem is now me. It shoots me 1/2moa consistently as long as I'm doing my part.
Here is some load workup with H1000 and 225gr ELDM's now
20210509_200256.jpg

And with IMR7977 and 220gr scenars
20210509_200239.jpg

All data taken at 200 yards. That is the furthest distance I was able to shoot at the range. It sucks that I put almost 400 rounds on the barrel before I looked at some obvious things. Next time I will start going through the rifle a bit sooner and use this experience as a training tool.
Here is the muzzle brake that I had on my rifle.
20201219_183145.jpg

And the one on it now during load development.
20210514_190402.jpg


Hope my post wasn't too long and helps someone else down the road. I've definitely learned a lot with my first build. Don't go cheap on anything!
 
I've had quite a few issues come up with my 300PRC during load development. So starting out I had just under a 1 minute rifle which really pissed me off. Granted I was shooting factory ammo for the brass. So when I switched to load development I found my powder charges. I'm using H1000, RL26 and IMR7977. I'm down to a pound of RL26 now so am usingtheothers. I did my seating depth test. I was shooting at 200 yards and still couldn't get it to group worth a shit. If I was lucky to have a group under 1 minute. I tried multiple powders with multiple bullets and was racking up the round count with no answers. I've ran 220gr ELDX, 220gr MK's, 220gr scenars, 200gr ELDX and 225gr ELDM's. I was working with and talking to my smith during all of this and we were about to recrown or rechamber my barrel. I'm running a 28" 9 twist M24 SS proof barrel on an Archimedes action. I couldn't find anything wrong with the crown or chamber. I decided to try one more thing which was to pull the muzzle brake and see what it changed. I loaded up generic loads with.. 2x Hornady brass, 215m primers, 220gr ELDX with 0.020" jump pushed by 74.5gr RL26 and another with 220gr scenars 0.020" jump pushed by 74.5gr RL26.
The 220gr ELDX with the brake shot about 1.5moa and without shot 0.750moa. The 220gr scenars shot right at 1 minute with the muzzle brake and shot about 0.500moa without. All shot data was taken at 200 yards. Another thing to note is I was getting single digit ES and SD's. The concentricity was checked,, bullets and cases were weight sorted for the above rounds. See attached pictures.
220gr ELDX...edited from 225gr ELDM's
View attachment 7631754
220gr scenars
View attachment 7631755
I was surprised and relieved that I had found the issue. I purchased a Area 419 Sidewinder muzzle brake and I now have a shooter. My rifles only problem is now me. It shoots me 1/2moa consistently as long as I'm doing my part.
Here is some load workup with H1000 and 225gr ELDM's now
View attachment 7631757
And with IMR7977 and 220gr scenars
View attachment 7631758
All data taken at 200 yards. That is the furthest distance I was able to shoot at the range. It sucks that I put almost 400 rounds on the barrel before I looked at some obvious things. Next time I will start going through the rifle a bit sooner and use this experience as a training tool.
Here is the muzzle brake that I had on my rifle.
View attachment 7631760
And the one on it now during load development.
View attachment 7631763

Hope my post wasn't too long and helps someone else down the road. I've definitely learned a lot with my first build. Don't go cheap on anything!
Good to know! Live and learn I guess; I am running an APA Fat Bastard gen three and love it.
 
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I run two COAL's..... 1. is 20 thou off the inside dimensions of my magazine wall....so I can reliably feed from the magazine. 2. is...I hold the bullet up to the brass...and you see the bearing surface to boat tail junction?.....then hold up your brass....see the neck/shoulder junction?.....line those two up with seating depth...and that's where the magic happens. On the 230 and 205 A-Tips...and the 245 EOLs...this means they are too long to be mag feedable....but for shooing ELR and benchrest or F-Class...or belly matches....PERFECT!

You may have to move yours 3-6 thou here and there...but those measurements are close for multiple rifles I've reloaded for.
Awesome thanks. Looking forward to trying it if I ever get brass or powder. What twist rate did you go with?
 
Good to know! Live and learn I guess; I am running an APA Fat Bastard gen three and love it.
I wanted a fat bastard but couldn't find one and settled on my second choice. It's an awesome brake. My brother is running a hellfire on his 300PRC and it works amazingly well also.
 
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Some times...when you use an 8 twist...and you get more RPMs out of your bullets....the A-Tips like to explodicate.....Poof...and now they are gone. Also...my personal testing shows that the 250's aren't good for the 300PRC....You just can't push them fast enough to out do the 230's.
 
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What problems does an 8 twist cause? I
plan on using 230 and 250 A-tips. Thanks.
The biggest potential problem is that if you spin faster than you need to, you increase the impact of any asymmetry in the bullets. It’s possible to have too much gyroscopic stabilization and the bullet will resist rotating into a curved flight path, but I think that’s not going to matter for any distance you’ll shoot a 300 PRC. You can also blow up some bullets with excessively high RPMs but I haven’t heard of that with the 30 cal A tips.

I don’t think 8 is too fast. You need 8 or 8:5 for the 250s, although I think the 250s are a bit heavy for the 300 PRC.
 
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I’ve been running 225s in my 300 WM and playing with AB mobile it looks like I should be able to get better with the 250s in the PRC. I was hoping to find a good load around 2800 fps. I was able to get on target on the 2010 yard target at Spearpoint with my WM and was hoping to stretch out to about 2600 with the PRC and the 250s.
 
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The biggest potential problem is that if you spin faster than you need to, you increase the impact of any asymmetry in the bullets. It’s possible to have too much gyroscopic stabilization and the bullet will resist rotating into a curved flight path, but I think that’s not going to matter for any distance you’ll shoot a 300 PRC. You can also blow up some bullets with excessively high RPMs but I haven’t heard of that with the 30 cal A tips.

I don’t think 8 is too fast. You need 8 or 8:5 for the 250s, although I think the 250s are a bit heavy for the 300 PRC.
So how do you figure out if your twist is doing the asymmetry gyroscopic stabilization bullet resisting flight path rotating stuff?
 
So how do you figure out if your twist is doing the asymmetry gyroscopic stabilization bullet resisting flight path rotating stuff?
Honestly I have no idea. I’ve only seen it written about for artillery, but some are convinced it can happen with shoulder fired weapons. I am pretty sure it’s only relevant to solids at extreme distance.
 
The biggest potential problem is that if you spin faster than you need to, you increase the impact of any asymmetry in the bullets. It’s possible to have too much gyroscopic stabilization and the bullet will resist rotating into a curved flight path, but I think that’s not going to matter for any distance you’ll shoot a 300 PRC. You can also blow up some bullets with excessively high RPMs but I haven’t heard of that with the 30 cal A tips.

I don’t think 8 is too fast. You need 8 or 8:5 for the 250s, although I think the 250s are a bit heavy for the 300 PRC.
a. That’s what I wanted to hear cuz everything I read seemed to point me to 1:9
 
Some times...when you use an 8 twist...and you get more RPMs out of your bullets....the A-Tips like to explodicate.....Poof...and now they are gone. Also...my personal testing shows that the 250's aren't good for the 300PRC....You just can't push them fast enough to out do the 230's.

I take it you’ve seen the a-tips explode in flight. I have seen references here and other places on the net that Hornady says not to exceed 290,000 rpm. 2,900 FPS ,for example, using the 230s or 250s in larger 30 cal magnums would seem reasonable. This would be approx. 260,000. What velocity in the 30 cal a-tips have you seen these explosions? Thanks for the help.
 
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I take it you’ve seen the a-tips explode in flight. I have seen references here and other places on the net that Hornady says not to exceed 290,000 rpm. 2,900 FPS ,for example, using the 230s or 250s in larger 30 cal magnums would seem reasonable. This would be approx. 260,000. What velocity in the 30 cal a-tips have you seen these explosions? Thanks for the help.

To my knowledge...I personally have never had a 30cal A-Tip explode in my rifle.....maybe once when I had a fairly easy shot with a no call. However....I've seen a few 8 twist barrels pushing 2950+ and seen the *poof* at 15-30ft past the muzzle.

Have you ever shot a bottle rocket up in the air...and it goes up...explodes and leaves that tiny little smoke signature?....that's what a few A-Tips I've see explode look like.
 
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Thanks for that info. That surprises me since Hornady recommends an 8.5 twis for the 250.

Yes..but look at the speeds they recommend. SLOW....the 250 needs to be pushed fast for the BC to kick in....I've found much better luck with the 230's past 2000yards. So....if you push them fast twist slow MV....fine....if you push them fast MV and slow twist fine....but when you are me...heh...and you push them fast MV in a fast twist.... POOF! So...I stick with 9 twist...and I think I've proved a history of good luck with it.

Today I'm testing a lighter bullet at more speed...we'll see how it goes....I'm just playing today....less about testing...and more about..."I just want to shoot".
 
Thanks for lett me pick your brain. I had just ordered a Shilen Howa prefit from NSS last week and they offer 8 or 10 twist. They do offer a 4 grove “ratchet“ rifling that might be gentler on the jackets.
 
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Thanks for lett me pick your brain. I had just ordered a Shilen Howa prefit from NSS last week and they offer 8 or 10 twist. They do offer a 4 grove “ratchet“ rifling that might be gentler on the jackets.
I pick @b2lee 's brain all the time, he is one of my best resources for the .300 PRC.
 
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I've had quite a few issues come up with my 300PRC during load development. So starting out I had just under a 1 minute rifle which really pissed me off. Granted I was shooting factory ammo for the brass. So when I switched to load development I found my powder charges. I'm using H1000, RL26 and IMR7977. I'm down to a pound of RL26 now so am usingtheothers. I did my seating depth test. I was shooting at 200 yards and still couldn't get it to group worth a shit. If I was lucky to have a group under 1 minute. I tried multiple powders with multiple bullets and was racking up the round count with no answers. I've ran 220gr ELDX, 220gr MK's, 220gr scenars, 200gr ELDX and 225gr ELDM's. I was working with and talking to my smith during all of this and we were about to recrown or rechamber my barrel. I'm running a 28" 9 twist M24 SS proof barrel on an Archimedes action. I couldn't find anything wrong with the crown or chamber. I decided to try one more thing which was to pull the muzzle brake and see what it changed. I loaded up generic loads with.. 2x Hornady brass, 215m primers, 220gr ELDX with 0.020" jump pushed by 74.5gr RL26 and another with 220gr scenars 0.020" jump pushed by 74.5gr RL26.
The 220gr ELDX with the brake shot about 1.5moa and without shot 0.750moa. The 220gr scenars shot right at 1 minute with the muzzle brake and shot about 0.500moa without. All shot data was taken at 200 yards. Another thing to note is I was getting single digit ES and SD's. The concentricity was checked,, bullets and cases were weight sorted for the above rounds. See attached pictures.
220gr ELDX...edited from 225gr ELDM's
View attachment 7631754
220gr scenars
View attachment 7631755
I was surprised and relieved that I had found the issue. I purchased a Area 419 Sidewinder muzzle brake and I now have a shooter. My rifles only problem is now me. It shoots me 1/2moa consistently as long as I'm doing my part.
Here is some load workup with H1000 and 225gr ELDM's now
View attachment 7631757
And with IMR7977 and 220gr scenars
View attachment 7631758
All data taken at 200 yards. That is the furthest distance I was able to shoot at the range. It sucks that I put almost 400 rounds on the barrel before I looked at some obvious things. Next time I will start going through the rifle a bit sooner and use this experience as a training tool.
Here is the muzzle brake that I had on my rifle.
View attachment 7631760
And the one on it now during load development.
View attachment 7631763

Hope my post wasn't too long and helps someone else down the road. I've definitely learned a lot with my first build. Don't go cheap on anything!

That is good info. Your issues sound a lot like the issues I have been having though I’m only just over 100 rounds in on this barrel it is still pissing me off.

Im running a 24” proof carbon w/ PA Hypertap brake, in a bighorn Origin, mounted in an MPA BA ultralite. I’m having wandering groups and struggling to get under 1 MOA. I’ll get two in the same hole and then a flier 1.25” away. It is maddening.

In the past week I’ve:
-Bedded the scope base. Even though it was pinned it still needed it.
-Skim bedded the V-blocks/tang in the MPA.
-Lapped the seekins rings, which I was also surprised to discover that they needed lapping even after bedding the base.
-decided to stop relying on the “wedge-lock” actions screws that come with the MPA and use loc-tite. The screws never seem to stay torqued.
-swapped off my USO MR-10 for a Vortex AMG that finally arrived.

I’ve been trying to develop a load with R25 and ELDX220s in Hornady brass. I finally got my Lapua brass and some H1000 in so I may restart the process with that if all of the above has no affect on grouping. But I will definitely be keeping the brake in mind now too.
 
That is good info. Your issues sound a lot like the issues I have been having though I’m only just over 100 rounds in on this barrel it is still pissing me off.

Im running a 24” proof carbon w/ PA Hypertap brake, in a bighorn Origin, mounted in an MPA BA ultralite. I’m having wandering groups and struggling to get under 1 MOA. I’ll get two in the same hole and then a flier 1.25” away. It is maddening.

In the past week I’ve:
-Bedded the scope base. Even though it was pinned it still needed it.
-Skim bedded the V-blocks/tang in the MPA.
-Lapped the seekins rings, which I was also surprised to discover that they needed lapping even after bedding the base.
-decided to stop relying on the “wedge-lock” actions screws that come with the MPA and use loc-tite. The screws never seem to stay torqued.
-swapped off my USO MR-10 for a Vortex AMG that finally arrived.

I’ve been trying to develop a load with R25 and ELDX220s in Hornady brass. I finally got my Lapua brass and some H1000 in so I may restart the process with that if all of the above has no affect on grouping. But I will definitely be keeping the brake in mind now too.
My 300PRC doesn't like the 220gr ELDX. My 300WM with a 9 twist bartlein loves them. So far the lapua 220gr scenars and Hornady 225gr ELDM's shoot well now that I've fixed my issues.
My 300PRC was all over the board before I found out what the problem was. I would get a few ok groups and then weird flyers. It was very frustrating. It sucks that I wasn't able to get it figured out sooner. Hind sight...I will always use a proven muzzle brake and will verify accuracy with and without the brake on.
Let me know if it is the brake. I am curious to see if it mirrors my results.
Jeremy
 
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Just for an FYI...I did some load testing today...barrel was already fouled when I ran this test group. Brass is virgin Lapua...so that may be a factor...and I could probably dial in the group with seating depth testing and/or barrel tuner...but the differences in MV with ES and SD are just too far out of line with what I want to do with them...which is 1k paper. They failed in that regard...but I'll post the pics for your entertainment.

168gr Open Tip Match Bullets:

168group_300PRC.png


I could probably dial this group ^^^ in...a little shotgun-ish for me...the two in one hole looks good...but the horizontal is way out of line for me.

168speed_300PRC.png



ES of 32 is WAY WAY too much for me. I can dial my 245 EOL Bergers down below an ES of 10....but yea...this is virgin Lapua brass....I may revisit tomorrow when I go back and do some more testing of other components. But to see a MV of over 3500 fps.....makes you think...but nope...these won't be accurate enough for the purpose I need them for.
 
Just for an FYI...I did some load testing today...barrel was already fouled when I ran this test group. Brass is virgin Lapua...so that may be a factor...and I could probably dial in the group with seating depth testing and/or barrel tuner...but the differences in MV with ES and SD are just too far out of line with what I want to do with them...which is 1k paper. They failed in that regard...but I'll post the pics for your entertainment.

168gr Open Tip Match Bullets:

View attachment 7632495

I could probably dial this group ^^^ in...a little shotgun-ish for me...the two in one hole looks good...but the horizontal is way out of line for me.

View attachment 7632496


ES of 32 is WAY WAY too much for me. I can dial my 245 EOL Bergers down below an ES of 10....but yea...this is virgin Lapua brass....I may revisit tomorrow when I go back and do some more testing of other components. But to see a MV of over 3500 fps.....makes you think...but nope...these won't be accurate enough for the purpose I need them for.
The other thing is that they still get smoked on wind at 1k by the A-Tips.

1621880236527.png
 
The other thing is that they still get smoked on wind at 1k by the A-Tips.

Yea...with these...I would have to hit the big light switch on the right pole to turn the wind off....if it is a consistent wind...doesn't bother me too much. Tonight I'll load some just a bit longer...I was trying to match the boat tail with the neck/shoulder junction...and the bullet is just too short for that...so I'll do like maybe half the length of the neck....the powder fill was almost 95% at the seating depth I selected.

I was getting about 2880fps out of the 250's today....was right at about 90F outside...brass looked good....but I'll stick with the 230's until my truck load of 245's come back in stock.
 
Midsouth had 8# jugs of R26 in stock for a whole 45 seconds. Got an order in. We’ll see if it ships. It was out of stock before I could post it up here. Hopefully it’s a sign it will pop up at some other retailers soon.
 
Update from testing the 168 match bullets in the 300PRC. I added an entire grain of RL-26...and the speeds were much better on ES/SD...but just a tad faster....average was 3520fps. ES was 27 across 15 shots. This was on non-virgin Lapua.....groups were barely under and inch though....3 5shot groups...and they weren't very pretty.
 
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