rodwha
58 Cal.
777 is tricky. Velocity is usually lower then BP. That lets the barrel rise more before the ball exits to hit high. It does NOT like any compression so it must just be touched by the ball or bullet. In BP cartridges you usually can't get enough in to equal BP.
I will give you all a hint for Pyrodex, good stuff but it breaks in shipment. I use a mesh cloth over a box frame to screen a new jug. I was getting poor results as the jug got lower to find fines of powder near the bottom. I get a large pile of fines that I burn up. Accuracy has increased a bunch. Pyrodex needs a little compression so I made a spring loaded tool to seat by putting it on the ramrod once the ball is down to get the same pressure each time. I push to bottom the spring. Works with real BP too. My friend throws his rod down and I told him some day the gun will fire from whacking the powder. Even smokeless can go off if struck.
Several things cause higher impacts, A heavier bullet or a slower one. It is when the projectile leaves the muzzle in recoil. What you feel at your shoulder says nothing. Putting more powder to add to bullet weight has the same affect and all the powder will not burn before the end of the barrel. Adjust so all powder is consumed at 3" from the muzzle.
We tried more once to have flares shoot out and burn in the grass. Velocity went down big time.
Actually Triple 7 gives much higher velocities than most black powders with the exception of Swiss and Olde Eynsford, but we are talking just barely lower.
Also the compression issue is with metallic cartridge loading. They used to state that to load in any other firearm to seat firmly, which I do and can say there isn’t anything erratic going on as the group’s are the same and the POI is the same as when I use Olde E.
I’m not even sure what this is supposed to mean:
“In BP cartridges you usually can't get enough in to equal BP.”
Triple 7 weighs considerably less than any BP but gives the performance level of the more energetic stuff so the same volume of T7 will give much higher velocities than say standard Goex and be close to what Swiss or Olde E would give.