Is any muzzleloader load sealed? Have we seen bullets leaving the muzzle for not only a PRB, but conicals, paper patched conicals/ What about modern plastic sabots? What about cartridge loads? Do any of them show the bullet ahead of all gases out the muzzle?
Standing bear has a point, as well, the velocity of released gasses from behind the ball or bullet is so great, they pass the bullet or ball immediately upon the projectile leaving the muzzle. A coned muzzle would show this even prior to the projectile leaving or getting close (depending on the cone's depth) to the muzzle. As to whether ANY cloth patched ball can seal completely?
My paper ctgs. appear to seal, with that wadded up paper beneath the ball, which is held tightly to the lands by the double layer of paper all the way around it. That they, even a WW alloy gives identical accuracy to pure lead in the same ctg.s shows the ball is turning from the tight fit against the lands, the bunched, wadded up paper seemingly sealing. If it did not seal, one must think perhaps the paper would catch fire- it does not- in my loads, not in buddy Keith's loads, Bruce's loads or Dphar's paper patched loads - thus, THEY appeared to be sealing. Gasses flowing past a cast bullet, actually melt the lead which is well past the burning temps for paper and cloth as well. Really loose fitting patches used by people who have to wipe due to fouling buildup, cannot be found, due to ending up as incinerated shards of cloth - those I have seen, almost nothing left - saw a whisp of smoke and there was a piece (at Hefley) burning away. THAT is dangerous - obviously, proving that powder gasses are not sealed. What about those of us who can use the same patch for 5 loads and who's rifles are capable of shooting sub 2" groups at 100 yards, better than some modern rifles with scopes.
Do they seal?? I do not know for sure, however I do know I can shoot a tight group with used patches - at 100 meters or further - that I have done, even to the point of shooting a 5 shot 1" group at 50 yards, with the same single patch.
The .036" (14oz.) patches I used for the 100 yard group, I placed in my shooting box again, for when I forget to bring my patches - "again".
I hear you yulzari, concerning the deformation of the ball by making it fit so tightly into the bore. That I understand and that is actually covered in Forsyth's 1863 book. He talks about the standard fast twists of the day requiring tighter and tighter holds on the ball in the rifling to promote what he calls "resist stripping", as I think he assumes poor accuracy means stripping. The tighter and tighter loads, to the extreme of mechanically fitted balls as in belted balls being necessary- to give good accuracy with dangerous game loads, which are necessarily greater than NA deer, moose or elk loads.
That my rifle shoots well with such deformation of the ball is rather interesting. If I seat a ball into the muzzle, then withdraw it by pulling it out, the nose is a little less perfectly round that the base, however due to the use of the short starter's cupped ends, both for the long shaft and the short stub, the ball is rather non-deformed by the rudeness of which I assaulted it with, simply putting it into the bore. Yes - the balls had ratcheted impressions of the lands into the ball. Yes, these must as Forsyth says, impact upon the atmosphere - we KNOW today, they degrade ballistic coefficient, but that is a moot point at the ranges we normally shoot, ie: less than 300 meters. My .69 hits the 20 meter place out at our long range facility quite easily - Taylor was there when I was ringing it repeatedly, last summer The plate is about 16" square - it's a large target.
