I had feed problems with my LCP when I first got it. Same thing, it would jam when hand cycling the action. Tooling marks on the feed ramp and inside the chamber were obvious. I just polished the feed ramp and chamber using the procedure for the P3AT (the LCP is a knock-off). Fixed the problem.
The problem wasn't characteristic of the LCP. I just got a rough one, and was too impatient to wait for Ruger service at a time when they're making pitols faster than Congress is printing money. QC can be an issue with the best manufacturers these days
Ruger won't void their warranty over a polish job, so it was safe to do. Don't know anything about Sig's policies. Just sayin' it could be an easy fix by a good pistol smith.
A semiauto is worthless if it isn't reliable