The Plasma Rifle in 40 Watt range is 100% reliable, and almost maintenance-free.
Problem is, we gotta wait 10 years before they are invented. :(
Best thang to do is toss em a big can of wasp spray and shoot the can while they are holding it.... quick draw and tracer ammo optional.
As an aside, I remember that many years ago, somebody showed up at a Star Trek convention with a homemade “phaser”, which was a 5 Watt laser in a phaser housing, connected to a large battery. He bragged that it could easily burn through a cinder block.
They wisely refused to let him in with it.
This happened before lasers became very regulated. However, more recently, somebody noted that many ordinary green light lasers had a ‘limiter’ chip that could be deactivated with a soldering iron, making them strong enough to ignite paper or burn skin.