A thorough cleaning of gun and magazine both inside and out. The packing / preservitive used at factory is generally unsuitable as a lubricant, and must be removed and replaced with a good gun oil, before you make any judgement as to its reliability. Second, be very very sceptical of aftermarket magazines, if you have ever heard " well they worked fine for me, maybe it's your gun " run away from them. Have someone else shoot it before passing judgement, it could be you afterall. Ball ammo generally feeds better than HP, if it won't feed FMJ it's likely not an ammo problem.