Fully automatic assault rifles, anti-aircraft guns (that still operate), anti-aircraft missiles (that still operate), land mines over a certain size, or any Comp B. Those are on the naughty list.

There’s a whole community of folks building semi-automatic auto-return triggers that are “technically” semi automatic, but with just a gentle squeeze, fire off another. If you maintain that grip, the return mechanism engages, returning the trigger to firing position, where your pressure causes it to fire again… it’s called a Forced Reset Trigger.