How large should a percussian cap touch hole be?

by Bob Hatfield , Tuesday, September 13, 2016, 18:10 (2995 days ago) @ Byron

Black powder or a substitute? If a substitute probably the hammer will blow back to half cock by enlarging without helping the delay. Every side lock I had back in the day had a slight delay with pyrodex until I used pure black powder. The first thing I noticed after switching to black powder was that I could no longer hear the hammer strike the nipple a micro second before the bang.

With our flintlocks the rule of thumb is a touch hole no larger than 1/16th inch. I hole this large in a nipple will most likely blow the hammer back to at least half cock.

One thing about the Pedersoli breech. It most likely has a chambered breech. The communication hole is usually small around .25 inch at the most. 2fg black powder as well as the substitutes will hang up in this communication hole before reaching the nipple area causing the hangfires even with black. So if this is the reason using 3f will really help. Or if you must use 2 f then you should bang the breech with your palm to help shake the 2f into the nipple area. I have heard of persons removing the breech plugs and drilling out the communication hole and polishing the inside like a mirror.

Good Luck

Bob