I've wondered though, honestly, if it really is the fault of PVP that ammo and gun stats and abilities are changed. I'm more inclined that it's not exclusive to "balancing" pvp as much as the nerfs effect pve because the weapons themselves would be too power. The sniper ammo nerf that happened just before 335 light made sense because the King's Fall raid bosses would have melted far too quickly if the same ammo capacity was still in play. It's not just pvp but also to slow down the OP ability of high light guardians from making a joke out of the "challenges" of pve.