As a frequent shooter of many different rifles, including ones that fire intermediate cartridges, I can from personal experience say that the recoil in games is quite excessive. I think most people that pick up something like an AKM or one of its variants are surprised at how low the recoil's effects on a sight picture is. It is very manageable. 6.5 is even more so, having been designed to somewhat combine the advantages of the 5.56 NATO and larger calibers. The current recoil within the game is more reminiscent of a battle rifle cartridge, such as a 7.62x51 or even a .30-06.