25 prc? 25-7 prc? Experiences? Gotchas? Intangibles?

[Ucsdryder]

Nice, just ordered 138 Atips for mine. Let’s seen how they shoot.

Please post results!

 

[cal30_sniper]

25/300 WSM dies are available, and PBB has a chamber reamer for it. Good ADG 270 WSM brass makes an easy neck down. Essentially the same case capacity as a 7PRC but fits in an extended box short magazine which the 25-7PRC is just a smidge too long for with the 133-135gr bullets seated all the way out.

I’m putting one together on a Defiance AnTi-X short action with the Unknown Munitions mag cut for a 3.150” box.

6mm CM in the photo for comparison, these are the dummies I sent in to have the barrel throated properly.

 

[T_Widdy]

25/300 WSM dies are available, and PBB has a chamber reamer for it. Good ADG 270 WSM brass makes an easy neck down. Essentially the same case capacity as a 7PRC but fits in an extended box short magazine which the 25-7PRC is just a smidge too long for with the 133-135gr bullets seated all the way out.

I’m putting one together on a Defiance AnTi-X short action with the Unknown Munitions mag cut for a 3.150” box.

6mm CM in the photo for comparison, these are the dummies I sent in to have the barrel throated properly.

what case are they headspacing it off of?

 

[cal30_sniper]

what case are they headspacing it off of?

It uses the 300 WSM headspace (which is the same as the 270 and 325 WSM). Only the 7mm got the longer headspace, presumably to help prevent big whoopsies from 7mm bullets entering 270 barrels.

 

[T_Widdy]

It uses the 300 WSM headspace (which is the same as the 270 and 325 WSM). Only the 7mm got the longer headspace, presumably to help prevent big whoopsies from 7mm bullets entering 270 barrels.

Edit***** Hornady looks to have the wrong measurement. I should have looked at the saami prints as they are the same like you said.

I thought the 270 wsm has a .010 longer base to shoulder dimension to keep it from going into a 300 wsm chamber. Am I looking at these prints wrong?

 

[cal30_sniper]

Weird, Hornady seems to be consistently wrong in that measurement. Both my #10 and #11 Hornady print manuals carry the same incorrect 1.654 measurement for the base to shoulder dimension on the 300 WSM. SAAMI, as well as my paper copies of the Berger and Sierra loading manuals all list the same 1.664 measurement for the 270, 300, and 325 WSM.

The story I always heard was they bumped the 7mm WSM shoulder forward to keep it from mischambering in a 270. I never saw any accompanying explanation about what that set the poor sod up for that put a 300 in a 7mm though.

It's a shame they did the 7mm WSM headspace different from the others. Ballistically, it's the best of all factory options, but now you can't get good brass without fireforming the different shoulder for it.

 

[T_Widdy]

Weird, Hornady seems to be consistently wrong in that measurement. Both my #10 and #11 Hornady print manuals carry the same incorrect 1.654 measurement for the base to shoulder dimension on the 300 WSM. SAAMI, as well as my paper copies of the Berger and Sierra loading manuals all list the same 1.664 measurement for the 270, 300, and 325 WSM.

The story I always heard was they bumped the 7mm WSM shoulder forward to keep it from mischambering in a 270. I never saw any accompanying explanation about what that set the poor sod up for that put a 300 in a 7mm though.

It's a shame they did the 7mm WSM headspace different from the others. Ballistically, it's the best of all factory options, but now you can't get good brass without fireforming the different shoulder for it.

Do you have the barrel yet? Let us know the specs when you get it done. When my 25-7 is burned out I’ll be building a 25wsm

 

[cal30_sniper]

Do you have the barrel yet? Let us know the specs when you get it done. When my 25-7 is burned out I’ll be building a 25wsm

Not yet. I'll probably have it in hand early summer based on their lead times. I can definitely post some chrono'd load results as I start into ladders. I've got both N570 and Retumbo that should be good matches based on the GRT data that I've run, which puts either of them right at 3000fps with a 134gr ELDM from a 20" barrel within SAAMI pressure limits.