Primer seating pressure test

[JeffsSig]

Is there a way to test loaded primers to see if they are seated tight enough?

In brass that has primers only.

Small rifle

[timcalhoun]

Not that I'm aware.

I have loaded 38S until the primers fell out on their own. I usually load rifle on a single stage and so I'm seating the primers by hand. If I feel one that goes in too easy I chuck it. I imaging the gas pressure escaping around a loose primer could act like a cutting torch on the breach-face.

[gregintenn]

If there's doubt, I usually go with the straight edge test. If the primer is seated a bit below flush, it's usually good to go. I guess you could put them in a hand primer and see if they'll seat any deeper.

[Dolomite_supafly]

All you need to worry about is making sure it is flush or below.

Even if the primer pocket is loose the primer will still seal. As the bullet is fired the primer temporarily swells, sealing itself to the primer pocket. As a matter of fact the primer needs the extreme pressures to seal correctly. Try firing just a primed case and see how the primer backs out of the case.

During some testing I loaded some 7.62x39 steel cases. There were berdan primed but I used large rifle primers. The primers just fell into the pocket. I made sure to load the rounds with the rounds facing down so the primers didn't fall out. Upon firing the primers sealed themselves just fine and in most cases swelled enough to stay in the cases. People even glue LR primers into berdan cases and have no issues.

Dolomite

[JeffsSig]

Thanks.

Thats kinda what I thought and wanted to make sure.

Plus Info like this is hard to find and I thought others might want to know but didnt ask.

[timcalhoun]

Dolomie may be right that you only need the primer seated flush or below, and the primer may expand and eventually seal itself, but how much gas escapes before it provides a good seal? What amount of damage can this cause given the amount of ammo one shoots?

I've seen several 38S needing new top ends because of this very issue. In each case the breech-face was pitted badly. This round in IPSC open guns are notorious for loose primer pockets because of the high pressures they load. Granted, most of these guns were owned by shooters who shoot a LOT, but a breech-face should far outlast a barrel or 3 or 4.