Originally Posted by ronlaughlin (Post 3776965)

This morning i fired a few loads in the Triumph using W209 primer. The W209 grew about 0.010". The STS primer has plenty of fire for BH, but i am inclined to think the wouldn't be the best to use in my Triumph, because of their length. They would grow much more than the W209, and blow by would probably be an issue. If all Triumph have similar headspace, the W209 is probably the primer that will fit the best.

I believe my next breech plug project will be to decrease the headspace of the Triumph, so that STS will be the primer of choice in my rifle. Currently i am doing the same thing for one of my Omega.

Originally Posted by sabotloader (Post 3777028)

ronlaughlin

Ron, Builder might be OK, i shoot an even shorter Chedditie primer in my Triumph and really do not experiance much blow back at all in fact very litte. There is a dusting but not much.

This is the breech are in my Triumph after shooting 9 shots of 110 grains of BH and a very short Cheddite primer, it's length averages 0.287"...



This is accomplished by the length of the 'flash channel' in the breech plug. With the 'flash hole' on the end of the Triumph plug the volume capacity of the 'flash channel' is increased to the point where there is very little blow pressure felt on the nose of the primer - there-by reducing blow back