How do you figure? They are very efficient, an automatic weapon was designed for suppressing fire and getting rounds down range, if you are that concerned about accuracy get a sniper rifle. In the Marines each fireteam contains one M249 light machine gun or M240 medium machine gun. They are used A LOT more then you think. SWAT teams won’t use them because the majority of the situations they encounter are close range which does not require an automatic weapon, except maybe an MP5. But in most cases SWAT deals with situations with innocent civilians around so again though they can be accurate there will be bullets that go astray. No idea where you are getting your facts from on full auto weapons.