keyhole??

[a j cave]

why will some bullets keyhole in an acc. rifle.The same load just different 45 gr bullets. I've tried max > min powder charge & the gun will not shoot these bullets. I can get a 1" group with a few other bullets, Thanks AJ

 

[stocker]

It will be related to the twist in the barrel and the amount of bearing surface of the bullet within the barrel. Boat tails for example do not usually have as much bearing surface as a flat base bullet.