Okay, I've thought for a while that the game needed rebalancing, but what has been done with Patch 5.2 is a bit too much in my opinion.
Here is what I suggest.
1. No gun should need more than half of its magazine/clip to kill at any range.
2. The FG42 and the LS26 should be balanced like Assault Rifles rather than SMGs (25m effective range with a max of 10BTK).
3. All maximum damage falloff ranges for the SMGs should be increased by 5m across the board. Maximum BTK should be reduced by 1 for every SMG.
4. The M1 Garand should never take five shots to kill at any range, without Heavy Rounds it should be 4 shots past 50m, with Heavy Rounds it should only be 4 shots past 100m with a slower ROF (invert what it is now).
5. The MG42 and the VGO should have their damage ranges extended by 5m.
6. The Breda should have a high headshot multiplier so it only requires one full burst to kill within its effective range if at least one bullet is a headshot
SMGs were too good before the patch but now they've gone a bit too far to the other side.