How large should a percussian cap touch hole be?
I am working toward "optimizing" my David Petersoli Double Express rifle and am now looking at enhancing ignition. Most of the time it will fire instantly as in "bang" however it will occasionally have a short delay as in "clickbang". This is with both RWS and CCI caps which are top notch.
The nipples are a top manufacturer and in perfect shape and the caps fire every time. The touch is so small a little sewing needle will not pass through. It would make sense that a slightly larger touch of maybe 25-30 thousands would improve the whole process. I understand that too large a touch will vent excess pressure back out and I have heard that it can be so bad the hammer will re-cock itself...
Does anyone know of the "optimist" touch bore diameter that will balance increased fire in and limit pressure out.
Thanks in advance.
Byron
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
Black powder? You mean this old stuff?
In 1968 I worked in a newspaper mill at night and went to highschool during the day and made union wages of $3.00/hr when I was a sophomore and 16. Even though they don't ever make paper anyplace nice this was blue collar royalty as the going minimum wage was $1.60/hr back then. I had a Honda 305 SuperHawk motorcycle, hot older girlfriend (she was a 18 year old senior) and thought I was the shit. I could not hear a word my parents told me and pretty much did my own thing, most of it wrong. Still, I never ran into the law and by most accounts turned out ok.
I bought a reproduction .44 Colt revolver and a .69 caliber rifle shooting mini balls and shot the hell out of them. The guns are long gone but I still have a couple of unopened cans of the case of powder I bought at that time.
![[image]](http://i129.photobucket.com/albums/p239/yrusik/black%20powder_zpsqmrujog5.jpg)
Note the price tag of $3.80lb.
Note the minimum wage in '68 was $1.60 which corrected for inflation is around $12.00 in present money.
Note that corrected for inflation that old can of black powder cost around $25.00/lb and the hot headed 16 year old kid was making around $25.00/hr with quite a bit of over time...
Times change.
Cheers,
Byron
Go to Home Depot welding section and pick up a tip cleaner
by ERSisk , Tuesday, September 13, 2016, 22:25 (2995 days ago) @ Byron
about $4 it will be a blue and aluminum hinged case with progressively larger serrated wires and a small flat file for cleaning acetylene torch tips. Real handy for keeping nipples clean, clean, clean. Can also be used to measure exactly what size hole you have now. I would be cautious about drilling out the nipple. Nipples can be hard and difficult to drill with a tiny little bit, good chance of winding up with a broken bit stuck in the hole.