300 PRC update

[b2lee]

So did hornady, that’s why they developed the 300 PRC. To seat heavy for caliber bullets in a standard chamber and mag load from CIP magazines. None of which 300wm can do.

There is nothing wrong with the 300wm but there is no denying that 300 prc is a better designed modern cartridge; that is more accommodating and better performing with heavy for caliber bullets.

Yea...Hornady was like....We make bullets...we got some big, long, sexy bullets we want to sell people....but we can't stay true to SAAMI and load them into 300WM...unless we shove them down the neck into the powder....so they went the long way around and created a new SAAMI spec and called it the 300PRC.

Can you imagine if you could just willy nilly call anything a 300WM round...put it on the shelf at Cabela's and John J. Hunter tries to shove one into his Savage Storm..... "Hello...Customer Service?...I gots a problem"

 

[putput30]

Watch his videos comparing them. He's done the research, probably more than anyone on the planet so far. He's probably fired and tested many hundreds of rounds before he even makes each of his videos. And what you see is an unbiased testing of barrel lengths, bullet weights, etc... By trade he is an automotive engineer and a smart sumbitch. So he knows how to test and retest without skewing data or results.

In that comparison video he says he was using hornady brass in the prc and that it pressured out earlier than the 300 win mag. Im sure if he used a tougher brass like adg he could have run the prc faster and it would have outperformed the win mag.

 

[TripleBull]

Watch his videos comparing them. He's done the research, probably more than anyone on the planet so far. He's probably fired and tested many hundreds of rounds before he even makes each of his videos. And what you see is an unbiased testing of barrel lengths, bullet weights, etc... By trade he is an automotive engineer and a smart sumbitch. So he knows how to test and retest without skewing data or results.

Reading your post verbatim, I'd have to disagree. You don't think Hornady has much more 300 PRC research experience than Mark? I bet the OP of this thread has more 300 PRC experience than Mark. And I really like Mark and Sam, so no disrespect. One thing I like is that Mark and Sam are unconventional in many ways and are smart and driven enough to build their own solutions that work.

Another nit to pick: I think Mark at times puts the initial rounds for a new rifle on a video. Maybe I'm thinking of his 50 BMG, can't remember, but I don't think he worries about shooting many hundreds of rounds before starting to wring a new gun out on video.

 

[CNC-Dude]

Mark is thorough in his testing, and I doubt he is the type that finds a good combo a shouts success without rechecking several times to confirm his data because that's what engineers do. He seems very unbiased and encourages others to do their testing because he knows there are many ways things can be done and different conclusions can be drawn. But he has and does mention in other videos that are 30 caliber related that he has found both the WM and PRC are so close together in performance, that even in the gains one has over the other that they are too close to say one is better than the other. He has more testing coming this year for the PRC, so maybe that will reveal more pros/cons between them.

 

[Zback]

What are the most common primers everybody is using?

 

[davethedog]

What are the most common primers everybody is using?

Federal 215m is what I’ve found most easily, I do have some CCIs too

 

[b6graham]

Mark is thorough in his testing, and I doubt he is the type that finds a good combo a shouts success without rechecking several times to confirm his data because that's what engineers do. He seems very unbiased and encourages others to do their testing because he knows there are many ways things can be done and different conclusions can be drawn. But he has and does mention in other videos that are 30 caliber related that he has found both the WM and PRC are so close together in performance, that even in the gains one has over the other that they are too close to say one is better than the other. He has more testing coming this year for the PRC, so maybe that will reveal more pros/cons between them.

sounds like a severe case of confirmation bias after spending tons of money on custom reamer dies barrel etc

 

[Rocketmandb]

What are the most common primers everybody is using?

I've tested both BR-2s and 215Ms. BR-2s are more consistent for me, but I'm not shooting in the cold where they might suffer vs. more potent magnum primers.

 

[Swampbug]

What are the most common primers everybody is using?

Anything I can find....this is ridiculous

 

[CNC-Dude]

Anything I can find....this is ridiculous

I've got a box on Winchester Magnum primers I'll never use. I'd trade for a box of BR2's or BR4's...

 

[Swampbug]

I've got a box on Winchester Magnum primers I'll never use. I'd trade for a box of BR2's or BR4's...

Thx for the offer. I actually have enough LR primers (gave 5 pints of blood last week). Need CCI 450 or 41
for my smaller caliber guns.

 

[Fishkat]

Need a Little help.
Having issues resizing 300 PRC once fired Hornady and ADG brass. Using Widden Gunworks FL bushing die. Below are the before and after measurements of the brass at the 0.20 area.

Hornady: New 0.527 Fired 0.532 Resized 0.5315

ADG: New 0.528 Fired 0.532 Resized 0.5315

The base end of the brass is not being sized enough. If I read the SAMMI info correctly for this cartridge, 0.532 is within specs. Would some of you please let me know the measurements your dies are sizing the brass too in this area.

The die is setup correctly and I'm bumping the shoulder .002 -.003. The barrel was spun up by a reputable smith and shoots very well.

 

[2aBaC̶a̶]

Do the sized cases fit in your chamber??

 

[Fishkat]

Do the sized cases fit in your chamber??

Yes they fit in the chamber and accuracy is fine the problem is sticky bolt on ejection, some more then others and occasionally some force is needed to eject the fired case. You also end up getting false positive pressure signs on some of the cases and that being ejector smear.

 

[Swampbug]

It was a good day today.
Made a 4 hr round trip drive to buy the RL 26 and then the brass from the recent ADG release showed up in today's mail. Maybe 2021 will be better!

 

[Swampbug]

Pic

 

[shoot4fun]

At this point I don't need load advice as much as hardware advice. I have a 9 twist HV 30 caliber blank (Kreiger or Brux), ADG 300PRC brass, a good number of Berger 230 OTM Hybrid and 215 Hybrid bullets, Retumbo, RL26 and a couple more powders, magnum primers in hand and a set of Whidden click adjustable FL bushing dies on the way.
My original thought was to simply do a new barrel for my trusty Surgeon Scalpel 300WM but it is still shooting vey well and I have a good supply of components. Now I'm thinking an entire new build but not sure which action will work best for those long heavy bullets.
What are you guys building on for the long and heavy Hornady and Berger bullets?
Are you finding the pics 300WM mags work well or do you wish you had gone with modified CIP 338 LM mags?

 

[Rocketmandb]

Need a Little help.
Having issues resizing 300 PRC once fired Hornady and ADG brass. Using Widden Gunworks FL bushing die. Below are the before and after measurements of the brass at the 0.20 area.

Hornady: New 0.527 Fired 0.532 Resized 0.5315

ADG: New 0.528 Fired 0.532 Resized 0.5315

The base end of the brass is not being sized enough. If I read the SAMMI info correctly for this cartridge, 0.532 is within specs. Would some of you please let me know the measurements your dies are sizing the brass too in this area.

The die is setup correctly and I'm bumping the shoulder .002 -.003. The barrel was spun up by a reputable smith and shoots very well.

What I don't get is the growth of the brass diameter after sizing, but regardless, the die isn't sizing it small enough. You may need to get Whidden to do a custom die for you.

I did that on my first 300 PRC barrel and it worked well. Now, my new barrel chamber is about 1.5 thou smaller and I need to get another custom done.

 

[Rocketmandb]

My original thought was to simply do a new barrel for my trusty Surgeon Scalpel 300WM but it is still shooting vey well and I have a good supply of components. Now I'm thinking an entire new build but not sure which action will work best for those long heavy bullets.
What are you guys building on for the long and heavy Hornady and Berger bullets?
Are you finding the pics 300WM mags work well or do you wish you had gone with modified CIP 338 LM mags?

You will need CIP length mags. As for actions, any of the long actions will work. My new 300 PRC is built around a Deviant.

 

[Fishkat]

What I don't get is the growth of the brass diameter after sizing, but regardless, the die isn't sizing it small enough. You may need to get Whidden to do a custom die for you.

I did that on my first 300 PRC barrel and it worked well. Now, my new barrel chamber is about 1.5 thou smaller and I need to get another custom done.

Thanks for the response, a tighter die would work as would enlarging the chamber but I don’t understand if everything is in spec why the problem. Not sure I understand what you mean about growth of the brass after sizing. New brass measures about 0.527, after it is fired the first time it measures about 0.532 then I resize it and only get about 0.0005 change to 0.5315. When I fire the brass for the second time it measures 0.532

hopefully someone will measure a fire piece of brass that has been resize for me

 

[DellaDog]

I’m using nearly the same components with the Whidden click adjustable die. I’m two reloads into the ADG brass and I’ve never had an issue with extraction.

 

[davethedog]

At this point I don't need load advice as much as hardware advice. I have a 9 twist HV 30 caliber blank (Kreiger or Brux), ADG 300PRC brass, a good number of Berger 230 OTM Hybrid and 215 Hybrid bullets, Retumbo, RL26 and a couple more powders, magnum primers in hand and a set of Whidden click adjustable FL bushing dies on the way.
My original thought was to simply do a new barrel for my trusty Surgeon Scalpel 300WM but it is still shooting vey well and I have a good supply of components. Now I'm thinking an entire new build but not sure which action will work best for those long heavy bullets.
What are you guys building on for the long and heavy Hornady and Berger bullets?
Are you finding the pics 300WM mags work well or do you wish you had gone with modified CIP 338 LM mags?

I am using CIP mags but I bet my loads could still fit in a 300WM mag. I’ve got a defiance tenacity on a KRG bravo chassis. I’m also using the hybrid 230s so I think that helps as the ogive is farther forward than some ELDs. If you haven’t chambered the barrel you can always get it chambered with however much freebore will work for you.

 

[shoot4fun]

I am using CIP mags but I bet my loads could still fit in a 300WM mag. I’ve got a defiance tenacity on a KRG bravo chassis. I’m also using the hybrid 230s so I think that helps as the ogive is farther forward than some ELDs. If you haven’t chambered the barrel you can always get it chambered with however much freebore will work for you.

I have been shooting the 6.5PRC for a couple years now and the two barrels I have chambered are SAAMI reamer spec (long free bore).
After some thought on using the 6.5 version in other venues I shoot (1,000 Yd BR) I just received a 6.5PRC reamer that is all SAAMI spec except with 0 free bore. I may spec a 300PRC reamer the same way. Got the latest 6.5PRC reamer from David Manson. He was so easy to deal with and delivered within his promised time that I'll go back there for the 300PRC.
I have an Alex Wheeler built 300NM 35˚ IMP done with a BAT HR, Krieger 9 twist, McMillan A6 and CIP DBM. I could pretty easily make it a switch barrel but seems redundant. I've given thought to a new Terminus, as I believe I saw that Joel is offering an action opened up for the longer cartridge lengths those big sleek bullets are giving us today.
We'll see for sure!

 

[2aBaC̶a̶]

Thanks for the response, a tighter die would work as would enlarging the chamber but I don’t understand if everything is in spec why the problem. Not sure I understand what you mean about growth of the brass after sizing. New brass measures about 0.527, after it is fired the first time it measures about 0.532 then I resize it and only get about 0.0005 change to 0.5315. When I fire the brass for the second time it measures 0.532

hopefully someone will measure a fire piece of brass that has been resize for me

I measured a few
New Hornady .5293
Fired .5320-.5325
Sized .5315-.5320

I have reloaded some as much as 4 times with no chambering issues.

I have a couple once fired cases from somone else that measures .53365 sized. No matter how many times I try, my die wont size the base enough to make it chamber.

My theory is. Standard die will only size that portion of the case so much and since its harder brass than the neck spring back is greater.

 

[Rocketmandb]

Thanks for the response, a tighter die would work as would enlarging the chamber but I don’t understand if everything is in spec why the problem. Not sure I understand what you mean about growth of the brass after sizing. New brass measures about 0.527, after it is fired the first time it measures about 0.532 then I resize it and only get about 0.0005 change to 0.5315. When I fire the brass for the second time it measures 0.532

hopefully someone will measure a fire piece of brass that has been resize for me

Got it on the resize - misread your original and thought you wrote the brass grew in diameter after resizing.

Heavy bolt lift can primarily be attributed to brass being too big going in or to over pressure. Even though you're slightly sizing down the case, and it goes in to the chamber easily, it still might be a large enough diameter that it causes a heavy bolt lift after firing.

When I was getting a friend into reloading with his 300 PRC, I used my old Hornady die for his initial loads of once-fire factory and had similar measurements to what you have. Every round had a slightly heavy bolt lift after firing. When I reloaded using my smaller diameter custom die, the problem went away.

 

[Fishkat]

I measured a few
New Hornady .5293
Fired .5320-.5325
Sized .5315-.5320

I have reloaded some as much as 4 times with no chambering issues.

I have a couple once fired cases from somone else that measures .53365 sized. No matter how many times I try, my die wont size the base enough to make it chamber.

My theory is. Standard die will only size that portion of the case so much and since its harder brass than the neck spring back is greater.

Thank you sir, exactly the info I was looking for. Our results are similar. After looking at the chamber and cartridge specs the best I can tell is that by design the cartridge/chamber can be very tight depending on the actual min and max tolerance values of each. So guessing it’s the luck of the draw if you have problems or not.

 

[Fishkat]

Got it on the resize - misread your original and thought you wrote the brass grew in diameter after resizing.

Heavy bolt lift can primarily be attributed to brass being too big going in or to over pressure. Even though you're slightly sizing down the case, and it goes in to the chamber easily, it still might be a large enough diameter that it causes a heavy bolt lift after firing.

When I was getting a friend into reloading with his 300 PRC, I used my old Hornady die for his initial loads of once-fire factory and had similar measurements to what you have. Every round had a slightly heavy bolt lift after firing. When I reloaded using my smaller diameter custom die, the problem went away.

I agree, thank you. I feel there is no doubt the heavy bolt lift is a result of limited space for the expansion/contraction cycle of the case. Doing some testing I’ve reduced these second firing loads by 2 grans from my summer loads and shooting in 30-40 degree cooler weather so the loads, still sticky bolt lift.
Guess I’ll check around to see who‘s taking custom die orders without a six month wait. This is one of my Desert Tech barrels so it might be easier to have the chamber grounded and polished a little.

 

[5RWill]

Anyone running the berger 245 EOL?

 

[b2lee]

Anyone running the berger 245 EOL?

Funny you should ask...look what was sitting on my doorstep when I just arrived home from work....on a Sunday:

I will test some of these this week....I'm guessing ADG Brass, Fed. 215M primers, 75.0 grains of RL-26....shoot one or two into the berm...get a MagnetoSpeedV3 muzzle velocity reading.....then shoot some two shot groups and move the tuner until they touch....then bracket some three shot groups through one ragged hole.....then confirm with a few 5 shot groups....then call it a day....

Come back...crunch some numbers with muzzle velocity and BC and see where it stands. Then shoot a few at 1 mile and check for vertical dispersion. Easy....Peasy

 

[5RWill]

Funny you should ask...look what was sitting on my doorstep when I just arrived home from work....on a Sunday:

View attachment 7519168

I will test some of these this week....I'm guessing ADG Brass, Fed. 215M primers, 75.0 grains of RL-26....shoot one or two into the berm...get a MagnetoSpeedV3 muzzle velocity reading.....then shoot some two shot groups and move the tuner until they touch....then bracket some three shot groups through one ragged hole.....then confirm with a few 5 shot groups....then call it a day....

Come back...crunch some numbers with muzzle velocity and BC and see where it stands. Then shoot a few at 1 mile and check for vertical dispersion. Easy....Peasy

What barrel length are you running and what's your target velocity?

 

[b2lee]

What barrel length are you running and what's your target velocity?

Barrel Length is 29.5" in a Bartlein 1:9....heavy varmit....with an Aaron Hip tuner and a brand new...never been fired 419 Sidewinder Magnum brake. Barrel has 97 rounds on it...should be good to go and not speed up any more....maybe.

Target velocity...depends on the temperature outside....somewhere north of 2850fps.....I'd like to run a lot faster....but I can't afford to lose any more primer pockets until the Lapua brass arrives.

 

[5RWill]

Barrel Length is 29.5" in a Bartlein 1:9....heavy varmit....with an Aaron Hip tuner and a brand new...never been fired 419 Sidewinder Magnum brake. Barrel has 97 rounds on it...should be good to go and not speed up any more....maybe.

Target velocity...depends on the temperature outside....somewhere north of 2850fps.....I'd like to run a lot faster....but I can't afford to lose any more primer pockets until the Lapua brass arrives.

Gotcha keep me posted. Its wishful thinking on my part but i have a 30 sherman build planned. But am trying to figure out how to get the 245 EOL to 2900 at 24" without moving to 300 Norma.

Has anyone considered the +p modification that defensive edge offers?

 

[ubettcha]

Gotcha keep me posted. Its wishful thinking on my part but i have a 30 sherman build planned. But am trying to figure out how to get the 245 EOL to 2900 at 24" without moving to 300 Norma.

Has anyone considered the +p modification that defensive edge offers?

The amount of flame coming out of a 24" prc will cut a 5'high snowbank to the pavement in 15 shots. I know this because I did it with a 24" 300 wby more than 30 years ago. I was running 85 grains of 7828 with a 180 smk to shoot across our pasture and be able to hold on hair. Didn't work out but the snowbank did get cut. Had plenty of unburnt powder in that experiment as well.

 

[2aBaC̶a̶]

The amount of flame coming out of a 24" prc will cut a 5'high snowbank to the pavement in 15 shots. I know this because I did it with a 24" 300 wby more than 30 years ago. I was running 85 grains of 7828 with a 180 smk to shoot across our pasture and be able to hold on hair. Didn't work out but the snowbank did get cut. Had plenty of unburnt powder in that experiment as well.

Lol,
I run a 24" PRC. No flame.

 

[5RWill]

The amount of flame coming out of a 24" prc will cut a 5'high snowbank to the pavement in 15 shots. I know this because I did it with a 24" 300 wby more than 30 years ago. I was running 85 grains of 7828 with a 180 smk to shoot across our pasture and be able to hold on hair. Didn't work out but the snowbank did get cut. Had plenty of unburnt powder in that experiment as well.

What is a suppressor for $500 please Regis. But yeah I'm still going to have to shoot for it. I might go 26" depending on how the resonator K sounds with that cartridge.

 

[LongRangeAggie]

Anyone running the berger 245 EOL?

Use the search function. I have posted data with the 245 and N565. Recently I tested it with N570 and had better velocities, currently using 78.0 grs in ADG brass at 2843 and sub 1/2 moa, 26" barrel.

 

[5RWill]

Use the search function. I have posted data with the 245 and N565. Recently I tested it with N570 and had better velocities, currently using 78.0 grs in ADG brass at 2843 and sub 1/2 moa, 26" barrel.

Never found the search function to work that well. Which is why i asked in a 74 page thread of load data. But those are solid results, +p 30 Sherman should get the 245 right at 2900

 

[b6graham]

Never found the search function to work that well. Which is why i asked in a 74 page thread of load data. But those are solid results, +p 30 Sherman should get the 245 right at 2900

Rich runs 245s at 3k from a 28" with N570

 

[Surly]

Just scored 8lbs of VV570. Was hesitant to get that much but it sounds like it should work well with the 245s.
I called Berger before I made the purchase (they put it on hold for me) to check before buying so much without testing and he said I shouldn't be on the phone with him but rather putting the order in for the powder LOL

 

[5RWill]

Rich runs 245s at 3k from a 28" with N570

I saw that i guess I’m wondering if it can be done at 24” without stepping up to 300 Norma. I feel like a 30SM +P will do it. But i could go 26” and run a shorter can and be at a short OAL than my 24” 7 SS with the hybrid.

Just scored 8lbs of VV570. Was hesitant to get that much but it sounds like it should work well with the 245s.
I called Berger before I made the purchase (they put it on hold for me) to check before buying so much without testing and he said I shouldn't be on the phone with him but rather putting the order in for the powder LOL

Whoa whoa what’s your source where you finding N570?

 

[Surly]

I saw that i guess I’m wondering if it can be done at 24” without stepping up to 300 Norma. I feel like a 30SM +P will do it. But i could go 26” and run a shorter can and be at a short OAL than my 24” 7 SS with the hybrid.



Whoa whoa what’s your source where you finding N570?

I found it here:

CAC Associates Inc - Reloading Supplies and Ammunition – CAC Associates, Inc.

I purchased the last 8 pounder. Apparently they are out of the 1lb as well.

 

[Jlknights61]

@5RWill

I think you’ll get there. I’m getting 2750 out of a 20” barrel with a standard 300prc chamber.

 

[codym]

Need a Little help.
Having issues resizing 300 PRC once fired Hornady and ADG brass. Using Widden Gunworks FL bushing die. Below are the before and after measurements of the brass at the 0.20 area.

Hornady: New 0.527 Fired 0.532 Resized 0.5315

ADG: New 0.528 Fired 0.532 Resized 0.5315

The base end of the brass is not being sized enough. If I read the SAMMI info correctly for this cartridge, 0.532 is within specs. Would some of you please let me know the measurements your dies are sizing the brass too in this area.

The die is setup correctly and I'm bumping the shoulder .002 -.003. The barrel was spun up by a reputable smith and shoots very well.

Common problem with ADG brass and Whidden sizer. This thread goes into it pretty in-depth. https://www.longrangehunting.com/threads/the-prc-die-problem.253223/page-12#post-2058785
I switched to a Redding FL sizer and was able to get the brass sized back to spec. Whidden blamed the problem on the ADG brass and were supposed to make me a custom die, that was almost 9 months ago. Needless to say I just requested a refund.

 

[Fishkat]

Common problem with ADG brass and Whidden sizer. This thread goes into it pretty in-depth. https://www.longrangehunting.com/threads/the-prc-die-problem.253223/page-12#post-2058785
I switched to a Redding FL sizer and was able to get the brass sized back to spec. Whidden blamed the problem on the ADG brass and were supposed to make me a custom die, that was almost 9 months ago. Needless to say I just requested a refund.

Thank you for the response and the link. Looks like this problem isn’t uncommon. I might just try to polish the first 3/4” of the chamber out a bit and see what happens. But the Redding FL die might be a better route, you mention that it resized the brass back to spec, could you give me what that measurement is.

 

[b2lee]

 

[Fishkat]

View attachment 7520188

Thanks, yep at the .200 line the SAMMI cartridge measurement is 0.532 and SAMMI chamber spec is 0533. Unfortunately for me the .001 isn’t working well and hoping that there might be a die out there that is sizing that area down a little more. codym mentioned back to spec and since most brass when new is .003 to .004 under the 0.532 at the 0.200 line and that possibly his Redding die was sizing down closer to that size as when new. I should have probably included the SAMMI drawing from the start, thanks for doing that.

 

[davethedog]

Yes they fit in the chamber and accuracy is fine the problem is sticky bolt on ejection, some more then others and occasionally some force is needed to eject the fired case. You also end up getting false positive pressure signs on some of the cases and that being ejector smear.

Are you using a comparator before and after sizing? I assume so if you are measuring your bump. Are the cases growing back exactly the same amount each time?

 

[Dooby]

What are clickers? The video in that thread is no longer available.

Edit: nmind found the Alex Wheeler video on his website

Videos | wheeleraccuracy

www.wheeleraccuracy.com

 

[b6graham]

Common problem with ADG brass and Whidden sizer. This thread goes into it pretty in-depth. https://www.longrangehunting.com/threads/the-prc-die-problem.253223/page-12#post-2058785
I switched to a Redding FL sizer and was able to get the brass sized back to spec. Whidden blamed the problem on the ADG brass and were supposed to make me a custom die, that was almost 9 months ago. Needless to say I just requested a refund.

i had the same issue with a whidden die and 7SAW

had to run the brass through a small base and then the new redding

wasnt sizing the web enough

my 2840 load was fine
on second load had to drop to 2800
third load i stopped and we figured out the issue

 

[Jlknights61]

Midsouth has Hornady 300 PRC brass in stock as of this post.