How large should a percussian cap touch hole be?

by Byron, Tuesday, September 13, 2016, 11:12 (2931 days ago)

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