Howdy,
Most of the frame cracking I have seen has been in or near the frame rails. I saw one pistol that would fail to go into battery after every shot because of a crack in the frame rails. It was a 6906 rather than a 6946, but it is the same basic gun, just DA/SA vs. DAO. At first we thought it was a shooter induced problem caused by limp wristing. A couple of us instructors tried it and had the same problem. We took it apart and discovered the frame cracks. Not the first time one of these pistols has cracked a frame, but the worst example I have seen.
"My" 6946 will sometimes lock the slide open with rounds remaining in the magazine. The slide stop is not pushed up when this happens, and neither pushing down on the slide stop or pulling back on the slide will release it. The only way to get it to go forward again is to drop the mag and then pull back on the slide and release it. It does this about once every 50 rounds, and none of us has been able to figure out why.
We also have a lot of problems with the magazines. The magazine seems to be a really weak link in the 6946. They rattle when fully loaded, the springs are weak, and we have seen a lot of misfeeds related to magazines. It is almost impossible to fully load the mag with 12 rounds, and it feels like the spring it completely compressed and bottomed out in the mag.
Not all of our guns have had problems, but a lot of them have. Three major departments in my area have all issued either the 6906, 6946, or a combination of both. Two of the three dropped S&W completely and switched to Glock because of reliability problems. The third switched to the 5943TSW, but is now looking at switching to Glock also because they are not satisfied with the 5943TSW either.
I expect the frame cracking problems are mostly due to use and the alloy frame giving out. The other problems related to magazines and unexplained failures to function seem to be widespread in the 69xx series guns regardless of age or round count. The 39xx series guns don't have the magazine problems, and my personal experience with the 3913 was excellent. That pistol would feed anything, including empty cases.
If you buy the 6946, you may get a gun that has no problems at all. Obviously some of the posters here own 69xx series guns they are very happy with. Police trade-in pistols tend to have had a lot more rounds fired than police revolvers did. I'm not sure a police trade-in pistol is nearly as good a deal as a police revolver is.
If it were me, I would not buy a 69xx series gun. The steel frame Smiths and the 39xx series guns seem to be fine. If you find a 3913 or 3953 you like, I would say go for it. I can't reccomend the 6946 based on my experience.
