There appears to be a bug when firing the m2 while it's set to full auto that removes all recoil.
After firing 3-5 bullets the gun just stops having any recoil whatsoever, even after you stop firing or after you reload. The recoil returns after you move the reticle, but moving your character without adjusting your crosshair allows you to maintain the effect.
https://1drv.ms/v/s!AsdgP-3dH6y-dkYbV0pRP2SHycI