If i understand the question, the hole is about 3/8" deep, and is a strong 3/8" diameter. For vent liners i use Holo-Krome screws.

This thread shows one way to modify the QRBP.

This thread shows one way to make vent liners.

Moderators please put this in the reference forum. Its a great how to.

In the years that have passed, since the standard QRBP was modified, i have used the CVA Blackhorn plug, and the Western Powders Blackhorn plug, and the modified standard plug. All three work good enough, i can not really tell the difference in their performance igniting Blackhorn. There doesn't really seem to be a compelling reason, to invest in the necessary drills, to do the modification to the standard QRBP. However, if one just likes to spend time out in the shop, that is reason enough.

Put all three plugs in their respected MLs and leave them outdoors (first thing in the morning) loaded horizontally standing, in sub-freezing weather for an entire day and then shoot those three, just prior to night skies.

That's when you may notice a difference in performance level....... or so I was told. The country's East/Northeast is where 80% of muzzleloader shooters partake. More humid there (versus South Dakota) and might be the proper place for that test.

You were told wrong.

What i do to test breech plugs is leave them outside overnight in temperatures -10 degrees or colder. All of these breech plugs will fire instantaneously, the next morning.


What in the world does that mean? Were you typing whilst sitting horizontally?

A gun laying horizontal on your lap is more like a hunting situation. A gun leaning up against a tree is vertical. Horizontal represents a real hunting situation in testing.

What difference would it make with BH209? As I understand it, BH209 is not hydroscopic therefore humidity should not affect it.

All three BP's will fire the same up to a point when none of them will fire.

Whatever condition could cause that is beyond me. It's probably way beyond what any of us would be hunting in.

I did not use the words vertical standing. What it means (to me anyways) is you don't have to stick around and hold the ML while testing it in non-muzzleloader season times.

But if you want to hold the gun(s) all day long, knock yourself out. Wouldn't shock me if you did.

Blackhorn powder will / can get wet and not fire. It doesn't have any shield over it, so water rolls off. The difference between it and others like Pyrodex and 777, is that it can fully recover 100% and not bear any after-effects in velocity and performance.