Looks like a good position for a .30 minigun.That would really eat into them.
No substitute for an M2, .50 caliber Heavy Barrel machine gun. Shoots flat, Armor Piercing Incendiery Tracers, kills effectively out to a mile.
Why use paint chippers with the same range as the enemy weapons?
Or, a well scoped 300 blackout with thermite tracers. Play hell with a boat or god willing a fuel tank.