I have seen Marines carry M-998, AK-47, PPPSH, A2, A3, M4, 249, 240G, and a slew of others but I cant name them all, and that is just in the pics on this board.
Dangit, not this argument again...
This one's been rehashed a bunch of times (not to hassle
doc2rn personally), but to summarize:
-I've heard rumors that some rear-echelon units during the 2003 entry picked up AKs for their "TO M9 only" personnel, who didn't feel warm and fuzzy just carrying an M9. Never saw such a thing personally. I've not heard of even rumors of front-line troops ditching their M16s in favor of an AK.
-In 2004, I saw a grand total of fewer than a dozen servicemen who carried non-standard arms. One USMC captain carry a FAMAS that he got from "somewhere", and a SeaBee petty officer who carried a folder AK. The others were all on one EOD team with a very, very accommodating gunny. The GySgt was M9 only, so carried a collapsing-stock Iranian G3 in his Humvee for emergencies, one of his LCpl drivers had a Sterling in the vehicle as a "to break contact, drive with one hand and stick other out window with subgun", and one kid mounted a PK-C onto a ring-mount since they were short on crew-serveds. I don't know if they actually used those individual items, but they used them to fill in gaps in their TO gear (and for bravado). That was literally all the divergence I saw on that matter.
-If you've seen lots of cool pics of servicemen carrying Iraqi weapons, it's likely that 90% or better were staged for the camera. I still regret that I never got around to my plan: go EOD, borrow their Shpagin (PPSh), and get one of their kids to photograph me pretending to clear a ladderwell in the EOD office.
Example:
(Not sure to thumbnail, so I'll just link to my example pic)
http://www.thehighroad.org/attachment.php?attachmentid=46787&d=1161581634
Looks awesome, but I got to hold it for all of two minutes, so be wary of assumptions based on photographs.
Oh, regarding the M14. In six months on a very, very large base in Afghanistan, I've seen all of three M14s. Two were in rather beat wooden stocks, and one was in an all-tricked-out modern stock (I don't know the brand or nomenclature). I'm still baffled by the wishful insistence that the US military is on the very verge of full-reissue of the M14 and M1911A1. I've seen one single .45 pistol in three deployments.
Just my 2c.