More about patch thickness.....gas leakage...

[oldracer]

No, not that kind of gas leakage you guys! I used my Doug Knoell made "mountain rifle" in our monthly black powder matches this past Sunday and I won the paper target match and was second in the steel match (two medals)! But I noticed that the round balls were dropping a bit more than I was expecting and since it was generally quiet for periods of time, when I would press the ball and patch down the barrel I could hear the air escaping through the rifling. The ball diameter was 0.495 and I was using a commercial patch 0.010 thick. The barrel is pretty short and not real heavy so I figured I was not getting as good a seal as I was with my 0.015 pillow ticking. To compensate I went to 80gn of FFG from 70gn and the drop was non existent with that load up. I would have switched to my home made pillow ticking but I only had a few with me so I finished the match as I started. I looked at the barrel with my bore scope and the rifling seems to be a bit deeper than most of my other guns but I haven't slugged the barrel yet.

Anyone have any thoughts about the air leakage issue? Here's a picture of this handsome shooter and the rifle!

[curator]

Did you recover any shot patches? If they were not sealing the rifling you would see burn-through spots. Congratulations for winning nonetheless since usually accuracy suffers if you are not getting a good seal with the patch/ball combination. Something I have observed in similar situations is the ability of heavier charges of FFg to act as a "filler" and seal off powder gas burn-through at least long enough for the ball to obturate sufficiently.

[johnson1942]

nice picture now i know what you look like when i talk to you by phone. oldracer use pillow ticking and a lube like spg for blackpowder cartridges. rub it really good into you patch both sides a few days ahead of the match. they will seal and no air or gas will escape. also if your very dareing and dont mind being told your nuts, go one step further. use lees alox to really wet your patches at leaste 3 days before you shoot them, let them dry 2 days and then again rub in thompson bore butter on top of the dreid lee alox and let them dry one more day. no blow by, no cutting , no comming apart. shoot in the same hole every time. it will solve your problem. i think your getting like me, it is getting to be a chore to decide what gun to shoot when you want to shoot. i see a lots of post about a lots of guns from you and they all are winners, but us old men need toys , dont we. just shot my long range target .50 and it sure felt good to hit the spot i aimed at even out to 400 yards. i pretend a buffalo just dropped. if you ever come to the black hills to vacation, let me know and we will shoot and visit.

[oldracer]

I did check my patches or at lease what I thought were mine and there were a few burned places in them which as you mentioned the seal was not great. I'll go back to pillow ticking and I have several bags that I cut last summer with Bore Butter as the lube and that worked very well. I do have to bang the ball/patch some as it is a much tighter fit with .015 thickness. I have found the BB to make the residue a lot softer and since I wipe between shots they are soft but a green color??!!