There's a way of telling if a model 10 is new enough to take +P .38s. I'm not an expert on classic S&Ws, but I seem to recall that the old "five screw M&Ps" was the "model 10" before it was actually called that. If it was called a "model 10" right when it first shipped, it should have a "10" stamped somewhere inside of the crane, on the part of the frame visible when you swing the cylinder out - and that's a good sign you can shoot at least moderate amounts of +P.
If I'm wrong, I hope to God somebody points it out
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The 10 is a good, reliable revolver. Tougher than an equivelent Colt of the same period (Diamondback or similar), not quite as accurate but then the Colts were exceptional. That 10 will keep up with just about any modern 9mm in the accuracy department.
If you have a choice, get a "round butt grip" model over a square. I like how the rounds feel, so do many others. If you find you like more of a swell at the base of the grip, Hogue makes grips that convert round-butts into the square-butt feel so if you start with a round, you can go either way
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What else...*definately* run through that checkout procedure on a $130 gun. Check timing and barrel wear as top priorities, minimal cylinder play at full lockup is priority #2, cylinder gap at .005" or .006" is acceptable especially if this is a 4" barrel gun or more. Make sure the ejector star ain't bunged up - having the ejector slip past a shell and end up with the rim under the star REALLY sucks
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Man, that's a good price. Is this by any chance a shooting range rental gun or something? If so, check it out good and if it's a newer model of the type than can handle +P, go for it if it's OK. If it's the older type, you can bet it's still had a pile of +P through it...I'd think very carefully about that situation!