Originally Posted by sabotloader

Breechplug

When you close your Accura is the primer held in the primer cup tightly against the breech block? If you were to check your Triumph - I think you will find that the primer is held fairly snugly in the primer cup as you pull the trigger guard up to the closed position... This certainly helps reduce blow back also.....

I could show you a prime example of this with my Omega and the 25 acp conversion if you want to drive a few thousand miles...

I think lee has also pointed out that there is no standard length in the world of shotgun primers... Winchesters being the longest - near .030 and Cheddite being one of the shorter @ .286 in length