Oh I also really like the HK91. It's acurate at 800 yards, and will picere truck armour too. Oh and if your good you can make it be automatic, but that's like illegal.
The old Stirling .410 shotgun and Lithgow Slazenger .22 single shot. I reckon I've had some of the best times in my life playing around with those two firearms.
For a real choice of "military" weapon, I would have to say the L1A1 SLR and M18A1 Claymore are my favourites, and I say this through experience and use, not through guessing and "I like the way they look"
I don't know much about guns. but i got 10 swords, one westpoint officer sword, 8 katanas and a tai chi sword, i think from that list you can tell my fave weapon ^_^