Hello. Yes, I have shot a .577 A Square Tyranosaurus in an A Square bolt gun built on the P17 action. The gun does not belong to me but to a dangerous game hunter buddy. Recoil is severe and you must have a solid grip on the rifle and be prepared for it. You can truly say that you've "been to the mountain" in terms of recoil. There is also considerable torque when firing this rifle. Having said all of this, the gun is NOT painful; it merely rocks you and pushes you back very significantly. The muzzle will be at approx 65 or 70 degrees when you bring it down from recoil. I have shot lightweight rifles in faster but smaller diameter calibers that hurt me. This would didn't hurt me, but it darn sure could if not careful. It is capable of taking anything on earth in my opinion. Ammo is something like $16 per shot if I remember right. The rifle's owner, a skilled bolt man, can rapid fire the thing at bowling pins set up to duplicate a charge, ie: one at 50 yards, one at 30 and one at about 15 yards. You then shoot the farthest pin first, and work your way in as though tracking a beast charging you. He can rapid fire the gun and load, hitting the pins each time. I am slower. Recoil seems more than 3 times an '06 and is awesome. My .416 is much more pleasent. The owner of the .577 much prefers the .500 A Square in that the .577 is right on the edge of what he can control. best to all.