7mm PRC Project

[JmacD]

Nor did I get the accuracy I was hoping for. Average for 10 3-shot groups was 1.100 inch. I hope the barrel will settle in a bit more. Next time out I'll try the 175 grain ELD-X Precision Hunter ammo. And I'm sure I'll be able (eventually) to work up a load the rifle likes.

That’s exactly what my barrel did on it’s first outing(I’m comparing apples to oranges as it’s a 308). All I could get was about 1.1 -1.5 at 100yds. Didn’t have a chronograph then. Every session it’s getting better.

Not bad for a first outing. I've found full builds usually take 50-100rnds to settle in.

For velocity, accuracy, or both? I’m saying both?

Edit: Just looking at pictures again. Nice looking piece for sure!

 

[Legionnaire]

Just looking at pictures again. Nice looking piece for sure!

Thanks.

Got the brass from the outing deprimed, wet tumbled, and dried. Had to order a new pilot and update the software in my AMP Mark II so I can anneal them before sizing.

 

[LoonWulf]

For velocity, accuracy, or both? I’m saying both?

Both, tho velocity usually continues to stabilize a bit over the next hundred or so.
Buuuut again my normal barrels are Shaws, amd while they don't show the kinda chatter or machining marks you see in Savage barrels.... they uhhh.... have some character.

I also think actually firing settles the component together somewhat. Again on really true pieces, probably not a thing.

 

[Walkalong]

For velocity, accuracy, or both? I’m saying both?

That might vary with the barrels.

My 6 Dasher barrels have all shot tight from the git go, but they are true match grade hand lapped barrels. They do gain velocity after a bit.

 

[horsemen61]

Thanks.

Got the brass from the outing deprimed, wet tumbled, and dried. Had to order a new pilot and update the software in my AMP Mark II so I can anneal them before sizing.

That’s one nice rifle!

 

[LoonWulf]

Hey just checking back to see if you've had a chance to tinker with this one any more?

 

[Legionnaire]

@LoonWulf, unfortunately, no. Summer travel, months of 100+ temperatures here in TX, and a heavy work schedule have conspired against me. It has been months since I've done anything at the range. However, the brass that I ordered in February finally arrived, I got my AutoTrickler running, and the temps have finally broken, so I'm cautiously optimistic I'll get out again soon. Thanks for asking!

 

[horsemen61]

@LoonWulf, unfortunately, no. Summer travel, months of 100+ temperatures here in TX, and a heavy work schedule have conspired against me. It has been months since I've done anything at the range. However, the brass that I ordered in February finally arrived, I got my AutoTrickler running, and the temps have finally broken, so I'm cautiously optimistic I'll get out again soon. Thanks for asking!

Can’t wait to see your results!

 

[LoonWulf]

Im looking forward to seeing more too!

 

[Legionnaire]

Took the 7mm PRC to the range with me today. My primary goal was testing 6.5 Grendel loads in the AR, but the PRC went along for the ride. Shot one box of factory ammo; three groups, then hit the steel at 200. Seems to be shooting in. Second group had a called flyer, as I pulled the trigger before I was completely settled. Third group was excellent!





I'm happy!

 

[JmacD]

Nice! And here I’m Still trying to decide if I’m tackling the 7prc or the 6GT first…

 

[Hugger-4641]

I'll take any of those groups with factory ammo in a hunting rifle!
I don't have time for a build yet, so I'm narrowing down choices for my 7prc. Right now I'm looking at B14 Crest, X-Bolt Pro, Savage Precision and Ruger Go Wild. Kinda leaned towards the B 14.

 

[LoonWulf]

I'll take any of those groups with factory ammo in a hunting rifle!
I don't have time for a build yet, so I'm narrowing down choices for my 7prc. Right now I'm looking at B14 Crest, X-Bolt Pro, Savage Precision and Ruger Go Wild. Kinda leaned towards the B 14.

As an avid ruger American fan....id probably skip the 7s in those rifles. None of mine have been as accurate as their kin... good enough, but as a group moa at best.

I think B14 or X-bolt would be my choice.....tho my Patriots stupid accurate and not horrible feeling... And I could be completely off base about the Ruger....

 

[WestKentucky]

Yeah, there's rosin in there. The heat of the friction when the barrel turned looks to have "melted" it. At least it was shiny and hard after pulling the blocks. I noted my smith used rosin, but then wrapped the barrel with a turn of paper. I might try that next time I need to pull a barrel.

I hear of seasoned veterans using sheet rock tape as a cushion along with rosin. I will be trying that on a emf SAA copy as soon as I get really set up and going in the new house. Somehow my honey-do list keeps growing before I get around to the things I want done. January is Manuary though so I’m working on the man room and the sheds. Hopefully setting up machining operation in the big shed.

 

[Okie_Poke]

Nicely done. Beautiful rifle. I have plans for a similar project to turn an old 30-06 into a 35 Whelen. Someday.

I have a question for you about the 7PRC, though. It may be too soon for you to tell, but are you experiencing any "clickers" (stiff bolt clicking at top of stroke when unlocking) on your brass after it's been reloaded a few times? I'm intrigued by the PRC cartridges, but reports of clickers with the 6.5 and 300 PRCs make me nervous about jumping in. I just can't tell if it's a real problem or something folks only experience when they're running loads too hot or not setting their dies up correctly. I'd appreciate hearing about your experience.

Again, well done on the rifle build.

 

[troy fairweather]

Nicely done. Beautiful rifle. I have plans for a similar project to turn an old 30-06 into a 35 Whelen. Someday.

I have a question for you about the 7PRC, though. It may be too soon for you to tell, but are you experiencing any "clickers" (stiff bolt clicking at top of stroke when unlocking) on your brass after it's been reloaded a few times? I'm intrigued by the PRC cartridges, but reports of clickers with the 6.5 and 300 PRCs make me nervous about jumping in. I just can't tell if it's a real problem or something folks only experience when they're running loads too hot or not setting their dies up correctly. I'd appreciate hearing about your experience.

Again, well done on the rifle build.

It happens with all cases like that, the prc,wsm,rum, ruger,blaser,Dakota, ext.

 

[Legionnaire]

@Okie_Poke, thanks for the compliment. Sorry; haven't done any hand loading for it yet, though that's the plan. I'm not overly worried about clickers in this or any other cartridge. I don't run max pressures as a rule, and setting up dies properly can help. The trick is sizing down as close to the case head as possible. I know they can happen with the PRCs, but not certain how many loadings before others are experiencing them.

ETA: Did some searching and reading up on your question. Looks like clickers are a known problem with the 6.5 and .300 PRCs; don't know if it's an issue with the 7 PRC. Looks like SAAMI-spec chambers are too tight at the .200 line. JGS makes a reamer that will solve the problem, available from 4D Reamer Rentals. I'll be doing some more research on this.