TexasCHLforum.com

Feeding issues that "develop" out of the blue could arise from several core issues. Here are the possibilities that come readily to mind.

Magazine related issues include:
- feed lips that are out of proper alignment - possibly due to striking the ground during reload
- Magazine follower perhaps hanging up a bit inside the mag
- Magazine spring with incorrect tension preventing proper alignment as the cartridge is stripped from the mag

Firearm related issues include:
- Chamber obstruction - not likely for an intermittent problem
- Extractor tension incorrect - preventing the cartridge from sliding up the breech face properly
- Feed ramp - not likely for a problem that developed recently unless the ramp/chamber has recently become damaged
- Magazine catch - if the magazine is not indexed properly in the frame the cartridge may not feed properly

Given that this is an intermittent problem, the first thing I'd do is visually and manually inspect and disassemble the magazines, clean them thoroughly, and then lightly lube them during reassembly. This may solve/prevent the problem without having to send the pistol back to S&W.