Do you feel like a dog chasing his own tail? That's where you are if the bullet isn't fat enough to prevent tipping on takeoff, and that holds true for any firearm. If good groups aren't consistent, there is a misfit in the bullet, or a poor bullet design, or something wrong with the bullet..... That row of dots means period! If the bullet design is strong, the mold well made so bullets are balanced, and diameter suited to the gun, almost any ol type of powder and charge volume will produce excellent groups if the load isn't so hot it strips the rifling.
For the 45 70 and similar rifles with very short throats, or space between cartridge neck and rifling origin,(which includes most lever guns) it is very important to have the bullet large enough to swell the cartridge neck to a close fit to the chamber. In most cases, forget groove diameter, which will be way smaller. If I have a throat slug I customize the bullet with a groove diameter forward drive band, which eliminates any deformation on entering the rifling, and keeps the bullet nose dead center. The rest of the bullet will come down to size rather quickly when the hammer falls.
Don't fret too much about details on bullet fitting if you order a mold from me, and send a throat slug etc as I request and prefer. With these things in hand I will make a bullet that will make you real happy.
I can take almost any rifle, revolver or single shot handgun, and make it print one inch groups at 100 yards with the first mold I cut, and not be too selective about the load if a rifle., (not auto pistol) The key factors are lap the bore if necessary, change a few dimensions if requuired , then fit the bullet. Everything else falls into place by itself. If you read this forum and understand all I write, or my book and other literature, you can do the same. (With a bullet I make, or perhaps a mold from another competent mold maker.)
