I bought a used S&W 640 marked .38 Spl on the barrel. Inside the cylinder frame opening of my 640,on the bottom visible when cylinder is opened, is stamped, "TESTED FOR +P+". This is a revolver stamped for .38 Special on the barrel, and +P+ is not a SAAMI standard. .357 magnum rounds do not fit in the chambers. I just got a response back from Smith & Wesson about this and the reply says the revolver CEN 5755 was part of a limited production and that .38 +P would not be a problem in this J-Frame. I am thinking of trying .357 magnum low end reloads in this revolver. Has anyone ever had experience with a S&W revolver stamped, "TESTED FOR +P+" before?
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