Rifle Brass with Small Rifle Primer Pockets?

[richhodg66]

On the 308W SP brass you will blank the primer if you don't have the bolt head bushed and the smaller pin fit to it. Especially bad in an AR10. But at the same time, it is not a bad thing to have your bolt bushed and a pin fit to it. Also the firing pin springs need to be changed at regular intervals also. Or you will start to see large SD variations. And primer flow even though the bolt has been bushed. The pins need to be strong enough to resist being push back into the bolt.

The only rifle I have shot the .308 SP brass in is a Winchester Model 70 bolt action, and then, only with low node loadings, but I've never noticed anything strange about the primers after firing. What you're saying makes sense, though, and I'll start watching more carefully.

 

[BBerguson]

The 450BM case is made with small rifle primer pocket which seems pretty silly to me…. If some one knows why it was developed like this, I’d love to hear It. Maybe the same guy that developed the 10mm with a large primer pocket…

 

[fiver]

same reason Casull switched the 454 over to small rifle primers.

the flash hole is smaller and 'back pressure' on the primer is reduced.

 

[358156 hp]

same reason Casull switched the 454 over to small rifle primers.

the flash hole is smaller and 'back pressure' on the primer is reduced.

They even went so far as to manufacture bushings to convert large primer pockets to small primers.

 

[BBerguson]

same reason Casull switched the 454 over to small rifle primers.

the flash hole is smaller and 'back pressure' on the primer is reduced.

That doesn‘t make sense though, there are lots of high pressure cartridges, higher than the 450 BM, that have large primer pockets. I would be more inclined to think they did it to give the base area more strength. But then, what do I know….

With all that said, I bought a 450 BM partially because it had small primers as I had an abundance of them and I wanted a large bore straight walled case in bolt action. So, got what I wanted but still a little confused by the small primer in such a large capacity case…

 

[fiver]

there is more strength there around the primer pocket.
nuthin really holds it in place or pushes against the case in a place that isn't supported.
the primer though,, it has a nice little hole right behind it where it can go.

 

[Mitty38]

I'm trying to figure out why the price of Large primers are staying about 15 cents each, while small primers are at 6.5 cents now. You think with the onset of small primers it would be the other way around.

 

[fiver]

it's the old story of supply and there's more stupids out there.