Thread: Ar15's with heavy projectiles

I have run 77gr TMK but I think that is the limit? ie the 80gr might be single load only? The faster the twist the heavier or rather the longer the bullet would be expected to be. In my case however while I have 1in9 the 77gr seems 1/8th~1/4th more accurate than 69gr TMK which I didnt expect. I would suggest therefore you try various bullets to see what the gun likes. I am going to try the 80gr for the hell of it just to see, but I really need to buy a good match grade barrel and build a new upper.