d.winsor

From what you wrote, i appears you don't understand the purpose of the o-ring. Western Powders furnishes the o-ring as a freebie. It is an option to help the shooter.. it is not required, it is an option. The same o-ring can be used in the CVA breech plug. What the o-ring does is seal the nose of the primer where it sits in the breech plug. This seal normally stops all blow by from getting around the primer.

A while ago, you wrote about, how to make this seal by shimming out the firing pin bushing so that the primer was 'slightly crushed'. Crushing the primer slightly, also makes for a seal against blow by. After you posted how to 'crush' the primer to stop blow by, you retracted your postings, because you were afraid it was unsafe. Actually, a slight crush of the primer is 'safe', but that is a different topic, best discussed in another thread.

Using the o-ring under the primer in either the Western Powders plug, or the CVA plug can stop blow by. The use of the o-ring in the primer seat isn't required. Using the o-ring in either breech plug, is just one way to stop blow by around the primer. The nice thing about using the o-ring, is it can stop blow by without crushing the primer.

One can purchase the o-ring from McMaster-Carr. The o-ring is so inexpensive, i toss them when i clean my rifle after every shooting session, even if i only shoot it once, or twice.




Another possibility, if one wishes to shoot Blackhorn in a CVA rifle, is to modify the standard QRBP. About this, i can furnish more information via PM.