According to a Smith and Wesson manual for revolvers revised 6/93 on page 11, it says that "+P ammuntion should not be used in medium (K frame) revolvers manufactured prior to 1958 (which are) identified by the absence of a Model Number stamped inside the yoke cut of the frame". If your revolver is a Model 10, it was manufactured after that date and is safe for +P ammuniton with the caveat that S&W recommends regularly checking for increased wear if you shoot +P exclusively or a lot. If you mostly shoot standard pressure for your plinking (which is likely), a modest amount of +P is highly unlikely to harm your revolver if it is marked Model 10 and is in good condition. I'm really conservative about shooting +P in older airweights (I don't do it) but have no qualms about Model 10s. It's my opinion but it's your gun, I'd keep asking till I was sure one way or the other.