While trying to unscrew the small brass screw it got damaged easily and no grip to use allen key anymore, anybody has an idea how to unscrew it? A24 part
Make a small guide bushing to go in the hole then very carefully use a left handed drill bit. It will bite into the brass and unscrew the brass piece. If not use an easy out in drilled hole to remove. Is the head broke off even or at an angle? If at an angle this can make drill bit scate off center. I am a machinist and a millwright and have done hundreds of this type or repairs large and small. Just be very careful not to damage gun. If you don’t have enough experience in this type of repair it is cheaper to send it to a Airgun smith than damaging gun.