no, it does not have additional wear on the motor. It's the same concept as turning the pinion gear with your hand when it's out of the gun.
And no, it will not strip your piston, the piston is only doing the same motion it did in a reverse. There is no reason why it would put any stress on the piston.
EDIT: Sorry didn't properly read what Amos said. Yes, if you pull on the trigger while it's rewinding, that will put additional stress on the piston.
However it is true you should have a reversal latch more than you shouldnt.
Last edited by Skladfin; October 1st, 2009 at 21:28..