Small primer in 6.5X47 Lapua

[Natty Bumpo]

Was curious why the 6.5X47 Lapua uses a small rifle primer. I see, according to the Vhitavouri reloading manual, with a 123 grain bullet, max loads call for 36-40 grains of powder. About the same as a .22-250. Seems like a lot for a small rifle primer. But, I figure the guys at Lapua know a bit more about internal ballistics than I do, so they must've had a good reason. Do most of the BR and PPC cartridges use small primers too?

 

[eddybo]

The PPC and BR both use small rifle primers. I have had no ignition problems at all using 40+ grains of powder in the 6x47 and 6.5x47. I am using winchester primers, a lot of guys are using the cci 450 magnum primers.

 

[spmorgan]

6.5 x 47 Lapua

I built a hunting rifle on the 6.5x47Lapua cartridge on a weatherby vanguard action and the combination is brilliant, the rifle drops Roos & goats very well out to the 500yds so I reckon they got the ballistics using the small primer spot on. Shane

 

[goodgrouper]

When the lapua x47 was in prototype stage, it was a large rifle primer pocket. Then it was changed to a small and they found it provided better ignition and more consistency which translated to better accuracy as well.

The 6 br also went through similiar changes in it's conception. The 6ppc does also use the small primer.

 

[LRHWAL]

I don't have enough experience to be commenting from experience , but from all I've read, the small primer pocket handles pressure better and takes longer to loosen (i.e. better brass life). That's logical - there's more brass around the hole! Also generally (again hearsay) more consistency and accuracy. Rem made 308 Brass with small primer pockets at one time too for the accuracy nuts as I understand, although I never saw any here in South Africa.

I'm sure the guys who really know from experience will chime in.