What different mags will work in the SW76? Do only original S&W mags work? Where do you get them? What is the going rate?
Yeah, S&W 76 mags (natch), MK-760 mags, Swedish K mags and Suomi mags will work with minor fitting, but usually any mag you "fit" to a gun won't work in the original gun anymore. Minor grinding/filing on the Soumis and K mags was always the cheap route and could be done to fit VERY tightly and when the Suomis first came out at $3.50/4 a pop, a LOT of them got sucked into the 76/760 world. A lot were also converted to M-10/9 guns but the fitting got rather involved. I did a few to say I did.
Like gold, 76 and 760 mags are where you find them. Going rate is also not really set. Some guys are really, REALLY proud of their mags and won't sell cheep.
Good PLACE to find the mags (all flavors) is of course, Knob Creek. How good of a negotiator you are will determine how much you pay. Generally, if you buy them ALL you will get a better deal. Don't be afraid to spend some money, you can certainly make it up selling the surplus amount you have and don't really want and almost get what you need for free...almost.