From day one i have had numerous issues with this rifle. Rifle would jam, not eject. Not fire. Got first one sent for warranty exchange at my local dealer. Second one same old story, could not get through full mag. Long story short, for all my friends out there, on here. The ACTUAL problem this rifle has is the Firing pin return spring is too strong for its operation. Yes, over engineered or whatever it may be. Solution, remove bolt carrier from rifle, take out cheesy little screws with caution. A few of mine were allready stripped from factory, nvm that. Take 3 screw plate off pin cover, careful spring does not fall or twang across room. Now you will see the spring, which takes wayyy to much force to move firing pin. Ok now take 3 full coils off spring. With side cutters. Re-install spring in housing same way it came out. (Make sure metal plunger on end of spring faces same way it was). Ok now you allready have cleaned inside everything, use locktite for bolt carrier small screws. Recoil springs are Tapered so make sure thinner end goes to bolt side, same way came apart. Perfect. Now you have a rimfire rifle that WILL fire everytime. Proper strike markings on head of cartridge. Thats all you need to know. Now you can finally enjoy your Issc rifle.