I have the 2500 kills title for about 4 assault rifles the mp7 mp9 barret and msr lol I never play with shotguns they are too inconsistent I did see a guy with the 1000 headhots title for the spas 12 which was pretty amazing to me since that gun is inconsistent

Mine was 1000 head shots and 2500 kills was with ump45

And I have 2500 kills for smaw

It was going to be something other than the fmgs.  Was GOING to be.

2500 kills with the SCAR-L, M4A1, CM901, MP5, UMP45, Barrett .50Cal.

Almost 2500 kills with the M16A4, Type 95, G36C, PP90M1

But, the first one I got 2500 kills with was the SCAR-L.

Stinger was my first but I've also done the M4A1, Scar and Model

P90 was my first the next is the Scar-L and after that the MSR........M4A1 then ACR 6.8

ACR, MK14, MP7, 50 cal, in that order.

UMP.45! I love it! You can use it w/ Silencer and Rapid Fire for the ultimate AR/SMG combo with the UMP's awesome accuracy! It was my first gold gun.

CM901 was the first followed by the ACR then the P90, Currently I have the M4A1 and PP90M1 sitting at 2475+ kills I will save those until I am done with my prestiges so I get the easy 10k xp to work on getting them golds. I also have the Scar, L86, Mp7, UMP, all within 1k of 2500 kills and am using those now, then when I get close I will rotate on to something else. Once I hit 15th prestige(13 now level 72) I will work on getting at least 10-12 different guns golden. Leaving the guns at 2475ish will be a great start to getting them gold once I stop at 15th prestige.

My first 2500 kill gun was the FAD...

Yeah Yeah I know... least it wasn't a n00b gun though ay?

My most treasured Title so far is the 2000 Stinger kills which I have had for ages but still only seen 2 others...

1: G36C

2: Mk 14

3: ACR

Only one I have so far is the MSR, which is odd since I never sniped in any of the CoD games before this one.  I'm a couple hundred kills off with about 8-9 different guns... next will probably be the L118A

The SCAR-L went from being one of my least used guns in the entire game to my most kills @ 2260. Ive used it almost exclusively throughout my current (7th) prestige and a bit in the later levels of my 6th prestige but until this time I only had around 500-600 kills with it. I recently upped my highest killstreak by 4 using this gun. My KDR went up a few points too. Im still using it and should reach 2500 with it fairly soon.

My first was the MP5, but since then I've gotten the Ak-47, p90, mp7, Acr, Scar, M4a1, Usas, Ump, Mk46 and the Fad.

I really have to give it to IW for gun balance, I find that the diversity for guns used in Multiplayer is the best I've seen for any of the CODs.