My buddy got an AR-10 in .50BMG. It has NO recoil at all. He took the first shot and this 245 lb fellow was afraid of the damage to his shoulder this beast would do. So he fired from a bench and the gun moved about an inch! It never touched his shoulder at all. Now that’s recoil mitigation for you.
Doubt it was an ‘AR-10 in .50 BMG’. Wouldn’t fit.