I just purchased a used TSW 3913 in excellent shape. My only concern is I don't know how many rounds have been fired through it and subsequently...how much wear and tear the springs and internals have been through. Do any of you make a habit of replacing springs and such upon purchasing a used auto? Although I plan on taking it to the range before I carry, I don't want to be stuck in a situation where something fails because it is worn out. Thanks for any input.