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
i believe you hit the nail on the head here for a blowback free ML.
i have three guns here that are blowback free,the triumph,knight vision and nef sidekick with metrics unlimited BP.
the triumph's toggle lock pulls the barrel assembly tight to the receiver and snugs up the primer tight in the primer pocket sealing the breech.the vision effectively does the same thing as it slightly crushes the primer when you close the action.
the metric's plug uses an o-ring to stop blowback as again it seals the breech.the metrics plug also does not have flash channel.when i had a knight shadow the simple addition of an o-ring turned that gun into a 100 % blowback free gun that shot blackhorn 100 % even in very cold temps.i do believe your on the mark with the larger flash channels helping with the carbon build up and really like the vent liner mods you folks are doing.i am going to try making a brass shim for the NFPJ plug for my disc-xt.this will go in the primer pocket to see if i can get a 100% seal
(it's only about 95% now)this thread has been a very interesting read.good luck to all.........karl