My friend, I appreciate your input and experience as is as valid as mine but I never used the word flatten. They become oblong as looking as very short tic tacs. Also, I referenced revolvers as I stated the that pistols with chamberS. Flintlock pistols do not have chamberS. In any any case all projectiles upon exposed to tremendous amounts of force will loose there original shape, period. Whether you can see it with the naked or not is a different story.Your post I referenced indicated round balls flatten into tic-tac shapes regardless of the gun, unless you're aware of some kind of flintlock revolver.
I have recovered PRBs from the berm. They do not deform.
As PRBs been recovered from a berm without deformation, I wish that was the case, we will re shoot them instead of recasting them. May be we are understanding deformation in different terms, the first deformation of a PRB happens when you push it down the barrel and the patch indents its pattern into it. At that point the ball does not have it original shape thus been deformed. I have attached a picture that shows how much rifling they grab, op to .125 of an inch.
I don’t want to go hi jack the thread but the same picture show balls that retained the home made Duro Felt wad all the way to impact and they were keyholing. I am not sure what produce the phenomena of attaching as I haven’t been able to replicate it. Some of those balls hit up to 8” away from the group. The Duro Felt was their BP material they sell cut with 15/32 punch (.468”) and wet lube with my home made lube which consist of food grade 1 pound of beeswax, 2 pounds of lamb tallow and 16 oz of Goya olive oil. The balls were pure lead. The gun a ROA with 30 grains of 3F GOEX at 25 meters (27 yds). Sorry for the long rant.