There was short, normal, long and bantam butts (I believe only Long Branch made the bantam butt.) to suit the various stature of soldier. The normal length stock is not marked but the short has a "S" near the butt plate on the top and the long has a "L" in a similar place. I don't know if the bantam butt is marked but would hazard at a guess that it is. There is about a 1/2" difference between the short, normal and long butts.