Welcome to the forum. You'll find there are three versions of the 3913, the original '91-99, the pre-rail TSW '98-00 and the the newer 3913TSW w/rail '00-up. The pre-rail TSW is my favorite but does use a shorter 7rd mag and has a shorter grip overall than the other two. It makes the mags and any aftermarket grip harder to come by, but the gun usually goes for a premium when found. I always look for used guns that still have the original box and paperwork with them, it usually means that they were better taken care of by their owners.