There is no need to nerfing it, It has its limits just like any other gun but because it cost much more its far less..
I bought the Gm4 because i started "Sparring" daily and needed a solid spar gun, Then came the great Bar nerf and started to realize the reason i was dying more often while basing was because of the reload nerf, So i turned to the GM4 and have not looked back... As Bitz Said 1 damage is not a big deal.... if i'm getting hit 1-2 times between long reloads on the bar.