Breechplug
Something has to hold the primer in... You do not think it is a magnetic thing do you? I know some breech plugs have that now...
I just mic'ed a T7 primer and they have a diameter .244 - I measured a Cheddite and it measures .2465. So they might be a little small but something besides diameter has to hold them in place.
Gotta go to the CVA site be right back... Well that was no luck... could not find anything...
Check with UC - he can tell you for sure -
But, anyway the shooting of the primer and the pressure should make them obturate out a bit to help make that seal. I am at a loss...
Ok two more thoughts just came to mind... I think Mountain Devil -Fronter Gander or what ever is experiancing the same thing you are talking about. He started a thread about wrapping his CCI ML primers with teflon tape to help seal the BP blowback - did not mention that they fall out of his Accura... so maybe this is common thing thing....
Second - I just tried a T7 primer on one my shot gun hulls. It dropped right in the primer pocket - no pressing neccessary - just turned the shell over and tap and it fell back out.... It is definetly thinner than a regular shotgun 209 primer, but only by a few thousands...
No my mind is running away - I thought you were a trap shooter also.. what primers do you use for reloading if you reload???
I keep checking my email looking for it... the picture