It happened once on my INFINITY open gun, just heat it up with small propane lighter and reverse drill it out with this US made extractor, don't use those cheap HF or home depot stuff, going to casue more damage, the best investment in my tool box and when the broken screw come out, the best feeling in ur life, lol.
https://www.thegrabitstore.com/collections/grabit-micro/products/alden-4507p-grabit-micro-broken-bolt-extractor-4-piece-kit