It's a case of shooting lots of .38's in a .357, you'll eat out the chamber slightly in front of the shorter case. Now, I'd bet you'd have to shoot tens of thousands of shorts to see this effect in earnest, but yes, it's possible. The only real concern is the fouling to the chamber as KDX mentioned. Now, I wouldn't go shooting shorts in your match LR chamber, but in your run of the mill .22LR, who cares. Not going to hurt it, just clean it.