Small rifle primers in 308

[chickasaw_hunter]

Had some antelope hunters in Wyoming one very cold year that had to make a trip to town and find some factory .308's to continue their hunt. The small match grade primers they'd developed at home (a warm state somewhere) wasn't lighting off.

 

[Walkalong]

Small rifle mag primers, stick powders, and have fun

 

[cougar1717]

Any small rifle primer has a certain amount of powder that it can effectively ignite, with a lot of variables like temperature, elevation, humidity, type of powder, case capacity, etc. The 308Win SRP came from competition demand, which is a relatively controlled environment, relatively full powder charges, and a lot of testing performed. The 308 Win SRP works - as substantiated by the existence of Palma SRP brass - but we shouldn't expect powder manufacturers to publish data for every circumstance, especially when it comes to reduced charge data, because the liability is too large. Even Starline's #2490 Match Brass has the asterisk with the caveats. At one time IMR made the reduced charge powder for large rifle cases, the discontinued IMR SR-4759. I'm sure someone, somewhere has a stash of that since it's the near perfect reduced charge powder for large rifle cases.

 

[W.E.G.]

Avoid CCI 400 small rifle primers for anything that runs at full modern rifle pressure.

Unless you don't mind pierced primers damaging your bolt.

I used this bolt to see how many chunks of pierced-primer metal would be needed to tie up the gun. Answer is: about 50. The gun finally quit cycling when enough chunks of primer metal accumulated under the extractor to cause the extractor to stand proud as the bolt tried to go into battery.

Once the piercing starts, the problem worsens in a linear fashion. I have plenty of AR bolts I can destroy. I'd be upset if I damaged a bolt in a gun that doesn't have a ready source for cheap replacement parts.

Save the CCI 400's for older guns that cannot muster enough force with the hammer-spring to ignite CCI 450 or 41 or BR.

CCI 450 or 41 or BR should ignite powder in medium-capacity rifle cases without any problem.

 

[Bwana John]

I read somewhere (PO Ackley?) that the safest primers to use with small amounts of fast burning pistol powders in large capacity rifle reduced loads were large magnum primers, something about air space and powder ignition.

I also saw the same thing expressed on the “Cast Boolits” website.

 

[W.E.G.]

Thank you for the information, I'd read on other forums that the powder in reduced loads might not ignite properly with small rifle primers , I know that bench rest shooters use small rifle primers but their loads are usually full power loads or mostly filling the case, im thinking about loading some light loads for just casual shooting, I've got a Mohawk 600 308 and it kicks like a mule with factory loads.

I've down-loaded .308 and 30-06 to see what effect it has on recoil.

I tested in my Garand (I have one in each caliber).

At about 36.0 grains the rifle became a single shot. I believe I was using Varget. Recoil was noticeably diminished.