(adsbygoogle = window.adsbygoogle || []).push({}); Me personally the hardest one was Model 1887 then pkp pecheneg.
The model took me half of my 5th prestige and the pkp pecheneg took me around 8 hours of 2x weapon exp.

The easiest gun for me was pp90m1. I got it gold the 2nd day of release only running rapid fire and extended mags. after that it was the l86 lsw. All I ran was grip until I got to level 30 then I did the rest of the attachments.

the easier were P90, pp90m1 and mp7
and the hardest i think it was the type 95. the model didn't seem very difficult to maneuver IMO i got it to level 3 and started getting the handle of it and now its gold

Defintely the models were hardest.. easiest was pp90. I've finally got all gold guns legit :p

The EASIEST is ACR. I don't know how you could think other wise. And I am unsure of the hardest.

I feel it is AA-12

Every time I would shoot I hitmarkered, it sucked so bad. They way I used it was in a nostalgic fashion, as in a CoD4 setup, it was actually pretty cool.

On subject,
Easiest: ACR, MP7 other such weapons. The Model 1887 isn't that hard when you really like the gun. I think I got it to level 30 on Xbox and I've been had it gold on Ps3 forever.
Hardest: M16 probably takes the cake.

the hardest is the model 1887 hands down

No, no, no, no, no the pre patch KSG-12 RAGE MODE ACTIVATED!

Not even try KSG-12 pre patch was still better than the spas-12 or the model.

Easiest acr ak 47 mp7 scar h model playing hardcore
hardest pm9 cm901 i hate the kick and draganof that one is pissing me off