It all depends on your style, so ill just give some great combo's for different style's Defensive/camper:
- Rpd - red dot sight (better field of view)
- Claymores (cover your back)
- Stopping power (makes it the fastest killing fully automatic weapon)
- Steady aim (for when your up close, cus its hip fire is dreadful)
Aggresive:
- Ak47/AK74u/Mp5 (the fastest killers 1 vs 1 when in close range, medium for AK47)
- Stopping power (kill quicker helps a lot in 1 vs 1)
- Bondalier/ frag x 3
- Steady aim
Long range:
- M16 acog/ m4 carbine acog/ g3 red dot sight
- Stopping power
- Steady aim
- Bondalier/claymores
Snipping, for snipping see my weapons analysis, as all snipper are pretty balanced.
Stopping is the best perk and it makes you kill quicker than any other gun, so you can kill the oponent before they kill you / before they go into cover / before you run outa ammo in your clip etc. its just the best perk.