The limitation isn't about accuracy, its about when they start cracking. I've found they generally start cracking in the necks about the 5th reload, as a matter of fact, I retire 223/5.56 cases after the 5th loading. Those are then recycled, they normally crack at the neck, and since the neck and shoulder are cut off when converting to 300 blackout, that's what I do with them, convert them to 300 blackout.