2nd post:
It is very hard to level but the game is still very even with newby guns and money is scarce once you buy a good gun and mod it to your liking and paintjob, there is the problem of speed hackers rarely but if you just leave and join a different match then its fine.
Also the guns in it have all their stats like Accuacy, Manuverability, Controll etc, and the have a % sign on the piece of equpement you selected and all around stats on the gun. AND underslung grenade launchers on assault rifles!
You can get guns primary guns like Snipers (semi/bolt action), SMG's (favorite from my experience), Aussault rifles, semi auto shotguns and Light machineguns (only M249 SAW and M60).
And Secondarys like various pistols, mac10, deagle, and shotgun.
There is only one SMG that can have a grenade launcher and it is the P90 (lvl 8) WICH I HAVE!!!
grenade launchers priming range is a bit much for a close quarter gun but if you use it right then you will see and improvement on your K/D ratio.
[Also heres a small list i threw together about what you want on your gun]
SMG's
If you want an smg you realy dont want to put together a gun with accuacy instead put together a gun that has manuverability AND you realy need controll thats the secret to SMG's and especialy the P90 being the fastest gun on op7, and pick a sight that is comvertable with how you play not one that looks kool and is gonna be in the way of your targetshead so you cant see, Lastly pick a paintjob that you like unless you want to blent in on a certain map... theres no point picking a camoflage paint job if your carecter himself doesnt have one.
Assault Rifles
Assault rifles are basicly all round and realy for alot of well placed shots not spraying like SMG's do.
these guns are the heart of the battle as they can put a few shots at a target at long range and alot in CQB maps while a sniper is only long range (unless you can no-scope like a few) and SMG's and shotguns are realy only for CQB maps. For this gun you need a combination of Accuacy, Manuverability and Controll and you get a great all round gun.
You can put a sniper scope on assault rifles but i dont recomend it as you get into the habbit of shooting alot and then the recoil is too big, So you can put on parts to suit you close quarter style or long range or just all round.
Snipers
Well theres not realy much to say about the sniper but you realy only need to put as much accuacy on as you can and there not one hit kill all the time so aim for the head when possible and pick a good snipeing spot so you dont get killed from behind. Snipers are the most expencive of all guns so you may need alot of money and costomising your character may not be an option in the long term.
Light machine guns
Great guns once you get to level 8 or 15. The level 8 LMG is the M249 SAW and you can realy only give it a different stock, sight, barrel and clip.... But very good and very powerful as it does more damage then the assault rifle and SMG.
If this gun takes you fancy then put on the large clip and the dot sight with the controll stock so you get a nice gun that has good controll for a LMG.
The level 15 LMG is the sweet M60 that is much better than the M249 and you can get attachments like a silencer for it a preview of the gun showd me that its fantastic! And if you pick this gun you will want controll.
Primary shotguns
Shotguns give you a nice little spread with one shot which means the are good in CQB and make a nice headshot if used properly. If you get a shotgun as a primary weapon then you may want controll and manuverability as out in the open your a easy target.
AND if you put a silencer on your gun then you need to know the fact that silencers numb the damage a bit so for something like a weak gun with a low fire rate i wouldnt recoment this
AND grenade launchers arent everywhere so you wont find massive numbers of people with them (because im pretty sure that the only one under the level 15 is the one on my level 8 P90)
They have a very low explosion radius and an awkward aim, and you only get two grenades.
Hope this helps you.