I have a new (to me) Yugoslavian M24/47 rifle. I have throughly cleaned and removed all of the cosmoline and cleaned the bore. The gun shoots surplus ammo pretty well, no real target work done just hitting what I aim at out to about 100 yards. I used a fishing weight and slugged the bore at 0.3253. It would seem that at this rifles velocity a gas check is needed..??... I would jump to the conclusion here that I need to make a cast of my chamber to determine the largest pill I can chamber. If my bore slugs at .3253 what size gas check do I need? Am I looking at a custom mold, or just some lapping of a stock mold? Any help, advise, or just your opinions would be greatly appreciated.