7PRC accuracy loads. SAAMI only.

FURMAN

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I know the cartridge has not been officially announced but a few forum members are playing with the cartridge using RCC brass. I would prefer you guys keeping your testing in your personal threads but you can post proven loads here. Please include all the data you can and group pics if you have them. Thanks!


UPDATE. IT HAS OFFICIALLY BEEN ANNOUNCED.


Check out the written guide!




Check out the video guide!


#7prc #7precisionriflecartridge #7mmprc #hornady #7 prc

 
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bayouSAUM

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yes, the write up is very well done! N 165 would be another great option

maybe i didnt see it, but will ADG and or Lapua be producing brass for this cartridge?

F class caretridges are perfected for 30-32" bbls and their slightly smaller capacity is supplemented with more bbl length, which hunting rifles dont have.....just somehting to think about, anyway....great write uo and video


my 7/300wsm with ADG brass is at 80.1 gr H20 capacity, fired, un sized
 
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Dmorgan46

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Ryan what is the COAL on the factory 175 & 180 and are you able to get the COAL for the 175's to the lands.
 

FURMAN

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I’ll measure the factory. I’ll have to pull a 175 to check distance to the lands. Give me a few days. Work is crazy right now.
 

FURMAN

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The same but better suited for long action.
 

FURMAN

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I should have been more clear. I would never build a short action magnum. The WSMs still need a long action. The 7PRC has WSM capacity but is slightly longer and skinnier which theoretically will feed better. As I have said numerous times the WSM feeds fine when adjusted properly.
 

Dmorgan46

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I’ll measure the factory. I’ll have to pull a 175 to check distance to the lands. Give me a few days. Work is crazy right now.
Thanks Ryan, trying to figure out how much shorter throat you could go on a custom reamer and still shoot factory ammo if needed, say 10 off, as the saami spec freebore looks long for bergers.
 

FURMAN

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Thanks Ryan, trying to figure out how much shorter throat you could go on a custom reamer and still shoot factory ammo if needed, say 10 off, as the saami spec freebore looks long for bergers.
My guide has pics of lengths with Berger 180s,190s, and 195s. I have no 175s to check. I personally would not shorten the freebore unless you were dead set on 168s.
 

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My 7mm WSM in a Classic M70 action, but with a 26" 9" twist Brux bbl. 66grs of H1000 pushes a 184gr Berger Hybrid at 3,000 FPS COAL is 3.195
 

FURMAN

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My 7mm WSM in a Classic M70 action, but with a 26" 9" twist Brux bbl. 66grs of H1000 pushes a 184gr Berger Hybrid at 3,000 FPS COAL is 3.195
Sounds like that is within the window of speeds I would expect out of this case capacity depending on several different factors.

We are going to keep this thread on topic.


7PRC
 

Dmorgan46

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My guide has pics of lengths with Berger 180s,190s, and 195s. I have no 175s to check. I personally would not shorten the freebore unless you were dead set on 168s.
Ryan it was more around the 175EH & 184 F-Opens I can see an issue, if you see the sketch I have done up. I used the coal from your 195 photo as a reference length, and then applied the following. In my 7SAUM the 195 touching is 3.050, the 184 are 20 longer at 3.070 and the 175 are 50 shorter at 3.000. So it will put the 184's at 3.561, these are only calculated number comparing projectiles in my SAUM chamber these could be different in the PRC. Say a 184 loaded at 3.550 at 11 thous off, is 80 thous seated in the neck enough? I would have through there would be a greater chance getting excessive run out damage, from a feeding issue, recoil, dropping, transport and just other weird shit that happens.

I not trying to piss anyone off, just trying to get all the info to make a decision if a SAAMI pre-fit or a custom reamer and blank is a would be better option.

7mm PRC COAL.jpg
 

FURMAN

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Ryan it was more around the 175EH & 184 F-Opens I can see an issue, if you see the sketch I have done up. I used the coal from your 195 photo as a reference length, and then applied the following. In my 7SAUM the 195 touching is 3.050, the 184 are 20 longer at 3.070 and the 175 are 50 shorter at 3.000. So it will put the 184's at 3.561, these are only calculated number comparing projectiles in my SAUM chamber these could be different in the PRC. Say a 184 loaded at 3.550 at 11 thous off, is 80 thous seated in the neck enough? I would have through there would be a greater chance getting excessive run out damage, from a feeding issue, recoil, dropping, transport and just other weird shit that happens.

I not trying to piss anyone off, just trying to get all the info to make a decision if a SAAMI pre-fit or a custom reamer and blank is a would be better option.
I got my hands on a 175 Berger. If you have one or two specific bullets in mind I would probably get it custom throated. I would find a smith that will do what you want. The best way is with a dummy.
tdnFbBR.jpg

nXThqw8.jpg
 

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any one shooting the 168 bergers in this case and your thoughts on it
 

FURMAN

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any one shooting the 168 bergers in this case and your thoughts on it
Not yet. I have shot them in this case capacity before 3100 should be an issue with h1000 in a 26”. I will probably try them in my next barrel. The 180s are shooting too good in this barrel and I don’t won’t to mess with it.
 

Stumpm2

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Not yet. I have shot them in this case capacity before 3100 should be an issue with h1000 in a 26”. I will probably try them in my next barrel. The 180s are shooting too good in this barrel and I don’t won’t to mess with it.
Do you see any issues with the SAAMI throat and using the 168s?
 

FURMAN

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Do you see any issues with the SAAMI throat and using the 168s?
It’s long for 168s but you’ll most likely be able to find a good load off the lands. I’ll test them in my next barrel.
 

NoMrcyNodak

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anybody used the bushing dies yet? curious what bushing you used?
 

Ladd

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This is RCC Brass 7 PRC measured at .3105” loaded. I would use a .307” or .308” neck bushing in this case for ~.003” neck tension to start. Hornady may not be the same and/or I measure using the sharp end of the calipers which may be different if measuring from the flat portion. So, I would have several bushings in this area.
EDC7CCFA-F447-4F0B-865D-1AA294455555.jpeg
 

FURMAN

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Hornady brass is .314 loaded. I would start with a .311 or .310 bushing.
 

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Hey @FURMAN, I know I've said this several times, but your cartridge guides and overall content are money!

I digress. My question is related to powder charges. Your listed charges in the PRC guides are usually well over the maximums listed on the Hodgdon site. I know you're running a 26" barrel and state everywhere on your guides to work up to maximum pressures. Totally understood. What I'm wondering is how low would you recommend I start for my 24" barrel? I'm just trying to save time and components a bit, as well as not miss a good node. For 180 Hybrids and H1000, should I start at 62? 63? Lower? Hodgdon has a min 58.7 to max 64.6 for this relative combo.
 

FURMAN

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Hey @FURMAN, I know I've said this several times, but your cartridge guides and overall content are money!

I digress. My question is related to powder charges. Your listed charges in the PRC guides are usually well over the maximums listed on the Hodgdon site. I know you're running a 26" barrel and state everywhere on your guides to work up to maximum pressures. Totally understood. What I'm wondering is how low would you recommend I start for my 24" barrel? I'm just trying to save time and components a bit, as well as not miss a good node. For 180 Hybrids and H1000, should I start at 62? 63? Lower? Hodgdon has a min 58.7 to max 64.6 for this relative combo.
Many factors affect pressure and the maximum achievable velocities. This is why you need to start low and work up. I believe Hornady's load data is more accurate than Hodgdon's as far as max. In my OCW video I describe the pressure testing I do with new to me cartridges. I would say roughly 5% drop from max and work up but this really only applies to like components. Some research or understanding of the components is needed to guess the max pressure. For instance the Federal 215M most likely will reach pressure at a lower powder charge than a CCI250. The 180 ELDM has a much longer bearing surface than a 180 Berger Hybrid and will reach pressure sooner.
 

JamesJ

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Much appreciated. I didn't think of the bearing surface of the bullet, too. Thanks again!
 

Precision77

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Good afternoon Ryan. I have a Lane Precision 7LRM that the barrel is just about cooked on and I’m tossing up sticking with the LRM vs moving to the PRC. I’m a handloader and have another 200 pcs of new brass for the next barrel along with dies…ect
I have been extremely happy with the LRM, even with the crappy old Hornady brass as ADG is $400/100 in Canada…. I’m thinking Lapua will most likely jump into the 7PRC though and that is an obvious step up in brass but I can’t see there being much, if any difference in performance. Any thoughts either way?
Appreciated!
 

FURMAN

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Good afternoon Ryan. I have a Lane Precision 7LRM that the barrel is just about cooked on and I’m tossing up sticking with the LRM vs moving to the PRC. I’m a handloader and have another 200 pcs of new brass for the next barrel along with dies…ect
I have been extremely happy with the LRM, even with the crappy old Hornady brass as ADG is $400/100 in Canada…. I’m thinking Lapua will most likely jump into the 7PRC though and that is an obvious step up in brass but I can’t see there being much, if any difference in performance. Any thoughts either way?
Appreciated!
I would not give up a 7lrm to build a prc.
 

Precision77

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Glad to hear that I’m not the only one thinking this way Ryan. I bit the bullet and bought a couple hundred 7LRM ADG brass so I’m set for the next barrel. Being in Canada I’m considering purchasing my own reamer as this isn’t a popular cartridge up here. Any suggestions on who I could get one from or specs I should request. I am running a Defiance Deviant action but I’ve never seen a 7LRM prefit and getting anything shipped up from the USA is a nightmare right now…

Appreciate your time and experience,
Alex

 

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