Practice practice practice. Safety off when you present (shoulder it, ready to shoot) safety on every time else. Dry fire. Work on manipulation around tight corners/door frames. You don't have to burn through ammo to get good at handling it, airsoft proves that. And don't be a noob trying to go easy on the charging handle either. If you "ride it forward" or don't do it with authority it can short stroke and not chamber a round.

In Minecraft