+p chamber by DE

[bowhunter1287]

Unless it is an XM or LA, don't +P. You can't get to the lands with a 6.5PRC in a SA mag as it is.
I am a little biased, but the PRC/SI is a great increase. I love mine.
I have a SA mag bolt face that will be needing a rebarrel fairly soon, and I will be going 26" 6.5PRC/SI when the time comes.
View attachment 628982

Lance do you think there is any room in the prc/si case to +p to see a gain on top of si?
I would think then it would basically make the prc/si about the same level as the 6.5 max

 

[bowhunter1287]

Well I got a quick response from UM and on the 6.5 prc it only gains 50-75fps so don't think it's worth the try or squeeze for that one.

 

[Shane Lindsey]

More oomph=more cartridge

 

[lancetkenyon]

Lance do you think there is any room in the prc/si case to +p to see a gain on top of si?
I would think then it would basically make the prc/si about the same level as the 6.5 max

If you have the mag length to seat the bullets out a bit more, maybe.
Here is the CBTO/COAL for six bullets in the 6.5PRC and PRC/SI chamber. These were just fire forming loads, but seated to the lands. SI is about .002-.003" more FB than SAAMI PRC.
With several bullets and powders in the PRC/SI, I got up to running them compressed at the top end. So "maybe" depends on powder and bullet choice. I highly doubt 10% more charge weight would be available, however.

 

[lancetkenyon]

Well I got a quick response from UM and on the 6.5 prc it only gains 50-75fps so don't think it's worth the try or squeeze for that one.

SI will gain you 70-170+fps depending on bullet/powder choice.

 

[bowhunter1287]

Thanks lance that is a lot of info I will just stick with going prc/si.

 

[lancetkenyon]

If you need the full spectrum of the testing info...

New "Test" rifle REVEALED: 6.5 PRC SI (Sherman Imp)

I am building a new rifle to test a new case design. I will preface it by saying this is not my design. But I was asked to be the beta tester for it. I cannot say much about it yet but will be in the future once testing begins. I am currently waiting on the reamer to be completed, so my...

www.longrangeonly.com

 

[DirtNap35]

From what I was told directly by DE, +P works best with cartridges that have plenty of case capacity to increase charge weights by 10-15%. 5-10% will get you back up to normal pressures and not gain much.

Did he mention examples of cartridges? Obviously 338 Edge is one of the best, but what about something like a 7 PRC?

 

[lancetkenyon]

Did he mention examples of cartridges? Obviously 338 Edge is one of the best, but what about something like a 7 PRC?

I have loaded for quite a few 7PRCs. I am usually using H1000, Retumbo, N565, N568, or N570.
With H1000, Retumbo, and N565, there is a little case volume left at max, but not much. N568 and N570 are usually full or slightly compressed.

Plus, 7PRC already has a long FB, so I don't think I would want to extend the throat much more as it is unless you are thinking 195s. The 175/180/184 bullets can already be seated way out there.

When I talked with them, the 7PRC wasn't out yet.