300 PRC/215’s. …again

[Pronghunter]

I know there are thousands of these out there, but I feel my set up is a tad different and can’t find much info.
I planned on shooting 245 Bergers when I swapped 300 RUM to 300 PRC but made a few changes and prob not for the best. Needless to say here’s where I’m at.
300 PRC
Defiance Action
22” Bartlein Carbon AND at 1:8.
I’ve yet to find anyone with the short 22” and 1:8 twist. It was intended for the heavies but wasn’t happy with the considerably slower velocities I “would” have likely had from a 22” barrel and 245’s. So here I am.
At my disposal I have N570, H1000, RL33, Retumbo and N565. Lots of it.
ADG brass and Fed 215M Primers.
I emailed Berger and they sent load data but it’s all based off 1:9 and 26” barrel. Can I still use their data and start on the MIN side and run with it? And with so much powder, to avoid countless trips, spend time and effort, is there one power that would possibly work better than the other with the short barrel? Seems N570 is but maybe not @ 22”?
Thanks.

 

[SkyScrapin]

My results using primarily 190s and 215s below. I also tried 185s and 178s but didn’t like the accuracy.

Reloder 26 will solve your velocity problem. Hard to find though.

H1000 gave me pressure without velocity. Also got a secondary ignition in my suppressor.

Retumbo gave me neither pressure nor velocity.

 

[AXEFORCE6]

I use Retumbo in mine. 26" barrel. 220 ELDX is at 2940fps. It has room to go but it shoots really well there so I'll leave it. N570 will be faster.

 

[Pronghunter]

Reloder 26 will solve your velocity problem. Hard to find though

Great. Which I don’t have.

I use Retumbo in mine. 26" barrel. 220 ELDX is at 2940fps. It has room to go but it shoots really well there so I'll leave it. N570 will be faster.

Thanks. Really just looking for info on the setup I have. (215’s/22” barrel/1:8)

 

[b6graham]

berger gave you the data

barrel length will have an effect on speed but shouldn't impact the data much aside from just powder burn rates

drop 1-2 grain below their MIN and work up to their max and see what your barrel does

assume 100fps less than their posted speeds for a rough idea

those max loads look SPICY btw. id be very cautious. some of those charges are well above what Sherman posts as max in the 30SM

based on barrel length i'd pick H1000 and N565 as they're gonna be a little faster powders burn rate wise. 26"+ barrels would start to benefit more from slower powders

there's a massive 300PRC load data thread that will have a bunch of info...you'll just have to skim through it

 

[Pronghunter]

berger gave you the data

barrel length will have an effect on speed but shouldn't impact the data much aside from just powder burn rates

drop 1-2 grain below their MIN and work up to their max and see what your barrel does

assume 100fps less than their posted speeds for a rough idea

those max loads look SPICY btw. id be very cautious. some of those charges are well above what Sherman posts as max in the 30SM

based on barrel length i'd pick H1000 and N565 as they're gonna be a little faster powders burn rate wise. 26"+ barrels would start to benefit more from slower powders

there's a massive 300PRC load data thread that will have a bunch of info...you'll just have to skim through it

Excellent! I found that thread yesterday and was trying to sort through it but just couldn’t find the barrel length and twist rate I have.
Appreciate the info and I’ll take the advice with the charge weight under minimum

 

[Supersubes]

Excellent! I found that thread yesterday and was trying to sort through it but just couldn’t find the barrel length and twist rate I have.
Appreciate the info and I’ll take the advice with the charge weight under minimum

Barrel length and twist rate mean nothing. You’re just sacrificing some velocity due to the shorter barrel.

 

[MOUNTIC]

RL26 is the solution here. 22" and 215s have worked well with it for me in a couple 22" PRCs. Spinning up another here shortly too. Like mentioned above the h1k I had pressure before I was satisfied with where I was at. Retumbo was a little slow. 8133 was pretty much same as retumbo. And I traded the N565 I had before testing it. I've settled in the 76.6-9 range on a couple different guns with your same components and RL26. Your load may vary.

Offer up a trade for some powder you have for the RL26 and I'm sure you will find some guys willing to trade. If your in CO shoot me a PM. I'll help ya out.

 

[Pronghunter]

Barrel length and twist rate mean nothing. You’re just sacrificing some velocity due to the shorter barrel.

Honestly didn’t know that. I thought I’d need the longer barrel to burn a slower powder. Thought shortening it up would leave power behind.
Thanks.

 

[Ckleeves]

Be careful with some of that Berger load data. IMO some of it is beyond spicy. The H-1000 in particular. 80 gr start? Wowza… Hornady shows max of 78.1 with a 212 which I would say is pretty accurate. I have maxed right under 80 in two different barrels with 215’s and h1000.

 

[b6graham]

Be careful with some of that Berger load data. IMO some of it is beyond spicy. The H-1000 in particular. 80 gr start? Wowza… Hornady shows max of 78.1 with a 212 which I would say is pretty accurate. I have maxed right under 80 in two different barrels with 215’s and h1000.

i believe their data comes from quickload. orkan had a major issue in another thread i remember seeing recently and berger failed to correct it

i don't even think the H1000 is the worst offender of 'spicy' in that data either

 

[Ckleeves]

i believe their data comes from quickload. orkan had a major issue in another thread i remember seeing recently and berger failed to correct it

i don't even think the H1000 is the worst offender of 'spicy' in that data either

Ya it’s quick load derived or at least that’s what they told me. You are right after looking through it close that H1000 isn’t even the worst offender. They had to have had something wrong in QL when they came up with those numbers. I got that same data from them a few years ago and laughed but kinda assumed it had been corrected by now.

 

[Pronghunter]

Just double checked after our move.
RL33 , H1000, Retumbo, and N570.
Doesn’t sound like any are great. I’ll have to post a trade in the classifieds once I get enough time/comments on SH.

 

[Jlknights61]

I used a 20” 1-8 twist and got 2750 with Berger 245s and RL50. Worked up the load based on Bergers data.

 

[Rocketmandb]

Be careful with some of that Berger load data. IMO some of it is beyond spicy. The H-1000 in particular. 80 gr start? Wowza… Hornady shows max of 78.1 with a 212 which I would say is pretty accurate. I have maxed right under 80 in two different barrels with 215’s and h1000.

Also note that ADG is pretty thick brass and has less case volume as a result. Start low with whatever powder.

 

[b6graham]

Just double checked after our move.
RL33 , H1000, Retumbo, and N570.
Doesn’t sound like any are great. I’ll have to post a trade in the classifieds once I get enough time/comments on SH.

try H1000 first. but yo can probably find someone to trade RL26 for one of the powders you have locally

there's no time/post requirement for the PX. its a pay system

 

[orkan]

Ya it’s quick load derived or at least that’s what they told me. You are right after looking through it close that H1000 isn’t even the worst offender. They had to have had something wrong in QL when they came up with those numbers. I got that same data from them a few years ago and laughed but kinda assumed it had been corrected by now.

I emailed them. I talked to them on the phone. Multiple times. They were somewhat dismissive, as I would expect them to be, having no clue who I am or if I know what I'm talking about or not. Very polite, but dismissive of the issue. They spent a LOT of time on the phone trying to convince me that their data is good and they are on top of it. I explained in no uncertain terms, "No, your data is not good... it is not fine... you're going to hurt someone." Then I provided them with ALL of my live fire velocity data on the 6.5PRC... which can be found here: https://www.primalrights.com/library/cartridge-guides/65prc

For the record, I had customers telling me they got data from them, with a 58gr start load on a SAAMI 6.5PRC with a 156 EOL. I was told "We used hornady brass, and that's how we got more powder behind it." I explained, there is no way hornady brass could take that max charge without blowing a primer and locking the bolt... even in a mid length action throated long.

I tried to tell them "There is no world where a 64gr charge of H1000 behind a 156EOL in a 6.5PRC is going to end well." They said they'd look into it. That was in march of 2022. Based upon recent customer conversations, they are still handing out data which is unbelievably hot. They may have altered it slightly, but for several projectiles it is still not in the realm of reason. The original data my customer shared with me was a START load of 58gr of H1000, and a max of 64. As you can see by my actual live fire data, much of which was collected with both a magnetospeed and labradar, their start load was my redline max. lol

What I don't understand is, how a company like that wouldn't just live fire test?

I did what I could. After 6 months of hearing reports from customers, enough to where it couldn't be customer mistakes, I contacted them. Then I stayed quiet about it publicly, knowing it might take a minute to fix. It's been roughly 5 months since that time... and here we are. Guess they figured I don't know what I'm talking about. So it's likely they'll need someone's rifle locked up or blown up before it will get proper attention. The majority of their bullets and cartridge combos show good data, but at some point, something must have happened? Perhaps someone that doesn't know as much as the previous guy got put in charge of it? If they don't take care of it, and quickly, their entire data set will be polluted.

Just so we're on the same page... here is what 60gr of H1000 looks like in an ADG 6.5 PRC case that HASN'T been resized... so it's as big as it can get. During testing, I hit substantial heavy bolt lift at 58, and the AMP press detected a compressed charge at 56gr.

Here's what a 156EOL looks like in that case, setup for SAAMI. It's not mildly compressed. It's MASSIVELY compressed.

Anyway, suffice it to say, it appears we ALL told them so... and they don't seem to want to listen. Do your own work folks. Start low, and use live fire data with components as close to what you're running as possible. Software simulation can not take the place of real gathered data.

 

[orkan]

I received an email from capstone today. (perhaps spurred on by the above post?)

The new 6.5 PRC data looks pretty good. It would seem to error on the low side, which is where I like to see published data. I suggested they give their 300PRC data a scrape, based on the above reports. (80gr of H1000?!?!)

Anyway, it's good to see they are addressing this finally. In the future, I would hope it wouldn't take a year.

 

[orkan]

 

[Ckleeves]

Glad they corrected the 6.5 data at least. I had forgotten how bad it was. When the 156 first came out I contacted them for 6.5 saum data and it was pretty accurate. Then the 6.5 prc data comes out and it shows starting load 1gr under max saum load!

I feel like quickload is pretty accurate if the input is good. Something went wacky with both PRC’s, thinking somebody input numbers from a RUM case accidentally!