That gun is a bit of an oddball given that it's set up to shoot 38 spl wadcutters only. If it's like other Smith autos of that era it has a magazine disconnect which is supposed to stop the gun from firing without a magazine inserted. It sounds like the bad mag is not making contact thus preventing it from firing.
I couldn't quite tell from your post if you were aware of this so I apologize if I'm telling you what you already know.
Originally Posted by tb-av
I have a Model 52 that is in like new condition with 2 magazines.
Bought it out of an estate. Both magazines are stamped S&W on the base plate.
One works and one doesn't.
The one that does not function will load up and allow you to rack a round in no problem but then you still can't pull the trigger. It's as though the frame thinks the mag is not present.
The good magazine ( facing downrange ) has a about a 1/4" wide piece that the round rests on. On the left is a shoulder that is molded in and maybe 1/2" down. Same on right.
Now the one that doesn't work seems as though that 1/4" piece is actually two 1/8" pieces sandwiched together. The shoulder looks about the same but also has sort of tapered molding above that lower shoulder section. I can't see that it actually does anything. There is one on right side too. Perhaps just some re-enforcement.
At any rate, does anyone know of anything I can look for to determine what is wrong. Any measurements of the metal case. Just by eye everything looks to measure up identical but it's clear they are not the same manufacture.
I also don't know how to get the magazine apart. I can get the base plate and spring out but that other piece has sort of an axle that rides in the mag frame. I figured if I could switch those I would know if it's the mag or not.