JonnyC: You should be able to shoot the revolver like that. Since the revolver is made of stainless steel it has the necessary strength to handle a +P load or two. Some of the S&W j-frames, through the metals used in their construction, are fine for infrequent use of +Ps but, if you really want to know what they have to say about your particular snubbie, call Smith and Wesson, they will tell you directly.
Also, even before S&W began providing that their j-frame snubbies were +P rated, one gunwriter took two out to the range, an older one and a newer one and pounded out 2,500 rounds of mixed bag +P loads. The result was that both revolvers shot better (or possibly that he was more practiced with them by that time is a better response) and that neither had developed any problems during testing.
But, you should also understand that you get very little, if anything more, from a +P from a snubnose than with a standard load. I have a number of snubnose revolvers and steadfastly avoid +P loads - I do not need the blast, the bark or the lack of performance from a +P from a snubnose. JMTCW. Mikey.