I shoot S&B quite often and no issues. I would suggest disassembly of the magazines. Clean and lightly lube the insides. Look at the follower. Mine had some mold burrs that I cut off and sanded smooth. Actually, I sanded the whole follower as smooth as I could. I used my wife's manicure bar with the four sides. Shhhh.

Re-assembly of the 7 rounder is a bit of a B*tch. When you load make sure the cartridges are seated as far back as possible. The slide has those weird swirl marks to help seat the bullets to the rear. Just tap the magazine on a table top to make sure.

It sounds like a lot but the magazine will loosen up after a short bit. Make sure you lube your pistol hitting the areas in the manual. Initially, nothing wrong with a bit extra oil just because it's new. Make sure you oil the barrel just in front of the chamber. Keeps it from sticking.

I would recommend at least 200 rounds to break in to see if any issues repeat and or clear up. After that carry on...