In the "Case" of the small primer pocket. There is no differences between the length of the pistol and rifle primers.

While I agree that loose primer pockets can leak. I believe that the harder rifle primers will cause more leakage than the softer pistol primers, because they are able to expand with less pressure, to seal the pocket.

Remember that the small primer and primer pockets, used in Millers and others are made for pistol primers at 43K CUP.

In any "case", given good primer pockets, if the primer can't leak and can't move, it can't cause damage.

One other thing that hasn't been talked about is the flash hole. Larger flash holes allow more pressure in the primer pocket and can cause leakage and damage in higher pressure loads.

Dave, do you know if they might have enlarged the flash hole on that rifle, in question?

Frank

I do not believe that simply have a good primer pocket fit will keep the Large Pistol primers from moving rearward and hammering the face of the breech block. When I was experimenting with them the face of the primer would be flattened persay by moving rearward and slamming the face of the breach block. I never found single one from the various manufactors in my tests that did not move rearward after shooting several thousand in load development tests. That and the fact that they did not show any improvement over the standard rifle primers along with fear of creating damage is why I eventually quit using them for any further load development tests. In regards to the primers bumping up and not creating movement I would not think there would be enough surface area in the primer cup along with the fact that the cups are quite a bit softer  that they could over ride the preasure working against it. We do know that the case body does indeed expand and then spring back and if using loads on the hotter side the web will also exspand and possibly the primer pocket would as well?

Just my thoughts and personal experiance for what its worth.
JLouis

I have some new RWS 5.6 x 50R Mag brass, that I bought here, to make 32 Ideal cases out of. I don't know the CIP pressure that this brass is designed for but, with the Mag in the name, it should be good for at least 357 Mag pistol pressures?

Measured with pin gages and a depth mic, the primer pocket dimensions are as follows:

Depth = .122

Diameter = .174

Flash hole = .078

If using 357 MAX cases, the pressure spec is, about 50K CUP.

The only brass that would be questionable, would be that for 38 Special but, I haven't heard of it being used for the Miller Short and it's not useable for the RKS chamber.

I think that I'd take a serious look at the head space on that Miller action.

Frank

Frank when I chamber my competition rifles / Schuetzen I head space off of the case so if one does not have a case in the chamber one would think my rifle had excesive head space. Not knowing how the Miller was chambered I would have Dave do the same so he does not get a false head space reading?

JLouis

jy3855 wrote on Mar 15^th, 2016 at 11:46am:


I destroyed the firing pin bushing in a Model J Falling Block Works rifle by using Remington large pistol primers in .32-40 cases.  The FP bushing in my rifle was not hardened.  I was fortunate to secure a replacement bushing from Leo Fix but the replacement also of relatively soft material. My guess is that all FBW actions were sold with soft bushings.

Constant battering of the soft bushing by large pistol primers caused the bushing face to recede over time.  It finally got so bad that the action became very difficult to open.

Again, this damage resulted from the constant use of large quantities of pistol primers for several years.  I don't believe that the occasional use of large pistol primers would be harmful.

JackHughs

I was using large pistol primers in my 40-65 with blackpowder back before it was fashionable to use them.  The breechblock on my original Hi Wall action
got peened by the primer getting a running start and slamming into block and I 
had to bush it.  After that I put a shim under the primer to get it close to flush
with the case head.  I never got any leakage that eroded the block just physical
damage.

Gentlemen: thanks to you all for enabling me to cross SP primers off of my list for load experimentation!