I uniform the primer pockets of all the rifles I reload. After acquiring a Marlin 44 mag rifle I just naturally uniformed the primer pockets as always. My first trip to the range resulted in several misfires. Using Rem brass, WLP primers seated with Lee Auto Prime hand tool.
Should pistol brass NOT be uniformed?

Pistol primers are not as "high" as rifle primers. Thus if you used the LR primer pocket uniformer on the .44 cases and then used pistol primers the primers were too deeply seated. The firing pin was not fully hitting them, that's why the missfires happened.

There is no need to "uniform" the primer pockets on pistol cases.

Larry Gibson

You have to remove material to uniform a primer pocket. Sometimes that puts the primer too deep.

All of the components in your firearm are made to tolerances. There are tolerances in mainspring strike, tolerances in firing pin protrusion, there are tolerances in primer cup thicknesses, and primer cake sensitive.

Tolerance stackup happens, and sometimes it does not happen to pistols alone.

I ream the primer pockets on the ammunition likely to be used in Garands and M1a’s. Not for accuracy but for safety. I want to ensure that there are no high primers. Any high primer in any semi auto mechanism has the chance of ignition through advanced primer ignition. http://en.wikipedia.org/wiki/Blowback_(firearms) A high primer would be exposed to impact from a fast moving bolt in a semi auto mechanism, I don’t want to take the chance of ignition.

Anyway while my rifle ammunition works fine in my M1a’s, I am having misfires in two M70’s. Apparently the CCI #34 primer is a little hard and it is buried a little deep.



I don’t uniform pistol primer pockets at all. I would not bother for your 44 Mag unless you had high primers.

Thanks for the replys concerning my uniforming problem. Would you happen to know if there is any information available concerning the size specification of different brands of primers? I thought if one particular brand of primer is a tad longer that would help for the 44 mag cases I've already uniformed.

quote:

Would you happen to know if there is any information available concerning the size specification of different brands of primers?

Yes; all primers of the same type have exactly the same SAAMI specifications.

As others stated if you happened to use a tool designed to uniform a rifle primer pocket you have probably gone to deep.

Here are the dimensions of the two.


According to SAAMI, the depths for small pistol, small rifle, and large pistol primer pockets are .118" to .122", while large rifle primer pocket depths are .128" to .132

If you have cut the pocket deep enough a large rifle you will have issues with the large pistol.