The factory sends out mixed messages about these. Some of the first 640s were marked "Tested for +P+" on the lower frame window, but as a group S & W will state they are not +P rated. On a practical level, occasional use of factory rated +P .38 Special will put extra stress on the gun but is safe.
The 640 is not an airweight ( alloy frame ) , it's stainless so I don't see a problem . I had a 442 airweight and that I shot +P in . Over time it did require a trip back to the factory as it was shot to the point of being very very loose after several years of use. Hope this answers your question ?
Last edited by cowboy4evr; 12-02-2016 at 04:42 PM.
I believe the 640ND is fine with +P ammo. The first one's built do have "Tested for +P+" on them, and the 640 was introduced at the same time as the 60-7. Since the 60-7 is ok with +P I would think the 640 is as strong.
My 640ND is loaded with +P ammo. I don't shoot much +P out of it, but that's because +P ammo costs more than FMJ or SWC, not because I think it is harmful to the revolver.
640 38spl
Linear Mode
