Best game I can think of with plenty of guns and violence on the terms it seems you're asking for is Max Payne 3. Yeah it's linear compared to RDR or GTA but you would be hard pressed to find another TPS that has better gun play, bullet wounds and physics.
The game is insanely detailed when it comes to bullets ripping through their targets and the reactions to the bodies as they are hit. Easily best physics, battle wound details and animations around in any game.
I don't care about the altitude, I just want another drink.