Recently I was looking at different parts for this pistol and I came across the question of certain parts for "American" or "German" Sigs. How do you tell the difference?
All I know is that the slide says N.H. (New Hampshire?),....is this American?
The original P220 had the heel release, which it retained when Browning imported them as the BDA. Then Sig put the mag release behind the trigger guard for the American market and imported the P220 and P226 under their own name. West German models from this period will have "Made in West Germany" stamped on the front left of the slide. They will also have the serial number stamped on the frame, just above on the slide, and on the barrel. Finally, there will be proof marks on bottom of the slide just below the muzzle and forward of the dust cover. One of these will be two letters, which reveals the date of manufacture.
Back then, Sig's American presence was located in Virginia I think. If it says New Hampshire, it's definitely American (the frames are still made in Germany though). A major difference is that all Sig's made in West Germany have folded and stamped slides, with internal extractors. Starting with the P229, Sig began to forge the slide to handle .40 and .357 Sig, and that has spread to the P220 and P226 as well. Forged slides have external extractors.