If I recall, they were full-auto only. I've never fired one.
I have shot one, though I forget if it had a semi-auto mode. I know it had a selector for two rates of full auto fire. It is very easy to do two round bursts. You have to be a bit quick to get a 1 shot burst.
I don't carry a gun to go looking for trouble, I carry a gun in case trouble finds me.