Further note about the Hot-Shot Nipples.
I did considerably testing with the 14 bore rifle with both the vented Hot Shots nipples and with standard stainless nipples. I threw away 1/2 dozen of the hot-shots after several months of rather intense testing to make certain my results were consistant and true. The results were that the Hot Shots dropped velocity averages slightly as well as degrading accuracy by approximately 20%. I don't recall how much the velocity was - perhaps 10% - hardly anything, but was there, as well as shot to shot variations increased to the teens from 3fps to 6fps or so.
I initially tried Hot Shots due to with low pressure loads like 3 drams of 3F or 3 1/2 drams of 2F, leaving the caps stuck fast on the nipple after firing. There wasn't enough blow-back pressure in that squib load to lift the hammer off the nipple and open the spent cap's slit sides. With normal hunting charges caps flared perfectly, but never blew or fragmented. I tried the hot-shots for the sole reason in getting pressure blow to open up the caps, which it did. What I didn't expect, was the drop in speed across the powder charge range, 82gr. to 190gr., and also the drop in accuracy, again, across the board. Switching back to solid stainless nipples brought back the accuracy. I learned to put up with prying off the spent caps with my patch knife when shooting squibs in deference to going easy on other people's targets.
No, the nipples weren't top-hatted. The lock had a descent buggy whip for a mainspring is all, hard at the start, then easing for the remainder of the movement. I don't remember if it was the L&R or Davis English Lock.
