Looks like a Victory Model, sans the usual lanyard ring, probably removed. Made from 1942-1945.
But the poor pictures leave me unsure if it's blued, re-blued, or has the normal Midnight Black finish for that model. That resembles Parkerizing. About 6,000 were actually Parkerized before patent issues arose.
The plain walnut grips do suggest a Vic, but may not be original.
Post better photos and someone will sort it out.
Give the serial number, inc. any letters,like V or VS. Those letters are part of the number and are very important!
Jack or Charlie or some other M&P expert will be along to tell you the date it was shipped, what the shop foreman had for lunch that day, and other details. You may need to pay $100 for a letter from Roy Jinks, the company Historian, to see where it shipped.
In the meantime, go to YouTube and watch the final clips of, The Bridges at Toko-ri, starring Wm. Holden and Grace Kelly, later Her Serene Highness, Princess Grace of Monaco. Look at Holden's .38 after he crash lands his F-9F Panther jet in Korea. Look familiar? You can also ID the knives the USN pilots wear on their survival vests.
What did you pay? Maybe $300? If it's in nice condition, fine. Some pay over $600 for a really prime example. But your grips are rough and the gun lacks the lanyard ring. I already mentioned the finish question.
IF it's a Vic, I often carried one in the USAF in the 1960's, as we were short of Combat Masterpieces and the Navy gave us a great many Victory Models.
The Victory is just a rough gray finished version of the Military & Police gun, the iconic Smith & Wesson revolver.
LATER: I just read Absalom's post. I looked again and think he's right about the S&W logo on the left of the frame. So, it probably is what he said. I initially missed that, due to photo quality. I should have copied the photos and enlarged Original grips were checkered, with silver medallions.