Straight to the point again the DMR in BF4 are indeed underpowered. Because there is no situation in which they outperform any of the other weapons in game. If you look at the TTK of the DMR even the QBZ can kill faster at range then most can up-close. I dont bother using them as any lmg while stationary and crouched can kill faster and be just as good as them. especially if go prone with heavy barrel+ bipod.
So here are my ideas- In no particular order
1. NOT very likely: Buff the damage profile to 50- 37.5
2. Add a multipler to the chest allowing if all shot hit becomes a 2-3 hit kill. Like the SKS had in BF3. Then buff the headshot multiplier allowing a 1 shot headshot upclose. Or just buff the damage upclose to be 50-30 for the dmage profile.
3. Make all DMRs 3 shot kills at all ranges everywhere on the body like BC2 semis were with magnum ammo.
4. Increase base accuracy, increase spread recovery and lower spread per shot while lowering recoil and increasing fire rates to 400-500.
This would mean that after this the DMRs could be fired as fast as possible theyd still be more accurate and would have lower recoil then before even with the increase in fire rate.
5. for all atttachments increase benifits and lower/ remove penalties. So attachments like muzzle break and heavy barrel wouldnt have their downsides or at the least they'd be lowered.
6. Increase range and muzzle velocity as well as suppression per shot to be like snipers drop off+ Then add long range scopes; would allow the DMRs to then be accurate mid range support.