Small primer Creedmoor

[Laurie]

Does a small flash hole have any implication for the preferred primer?

 

What primer would go well with this new SRP small flash hole 6.5CM Lapua brass? Would you get better results with a magnum SRP?

 

 

You can use standard primers, but they have thinner / softer cups (20 v 25 thou' thickness in BRs / SRMs). They may also be on the weak side for ignition in very cold weather or with ball powders. (Some ball powders don't perform well in small flash-hole brass and can produce hang or misfires with some primers and/or in some circumstances - can't comment on Ramshot grades, but H. CFE223 doesn't work in 308 Win Palma brass.)

 

So, don't use CCI-400, F205, Rem 6 1/2, the original PMC / Murom standard with the copper not brass cup. (Actually, these old Muroms are very good - if the bolt / firing pin set-up + pressures being generated allow them without severe cup extrusion back into the bolt / blanking, they can give excellent results in the 6.5X47 and 308 Palma, so should work well in the Creedmoor version too.)

 

That leaves all SRMs and BRs, the Murom SR223/KVB-223 and SRM, Fiocchi SR, CBC Magtech 7 1/2. They generally all work well although small flash-hole brass can sometimes produce primer sensitivity. Once a load is worked up, a primer change usually needs the load retuning to retain best grouping.

[johnnyb0_1]

To all who have added to this post, thank you. A very informative and steep learning curve. Every day's a school day, as the saying goes. This has certainly honed my thoughts on the new CM Lapua brass.

One question, will the normal, Redding S series dies have the required smaller size de- capping pin, required for the Lapua brass, or do I need to buy a specific one?

Thanks. J.