It is called the M240B. It has handguards and weighs about 24.2LBS; however, it is designed to be bipod and/or tripod mounted. The problem with going "Rambo style" ala M60 gunners in the movies is the priciples of machinegun gunnery get lost in the mix. Your medium machineguns such as the M60 and/or M240G are better used in a supporting role and are more effective when used as intended. The SAW (your light weight MGS) are used to get a lot of lead down range and are more maneuverable...... they are also light enough (and don't have such a heavy recoil) that they can also be shoulder fired.
Generally under "normal" conditions, one MG squad (2 gun teams) will attach to a rifle platoon. The gunner will carry about 100 rnds and the team leader and ammo bearers will split another 3-400 rnds or so. I notice that you say guys can carry bandeleers of ammo without problems....... the crap we have to carry now is HEAVY. There are all different types of electronics and weapons systems, grenades, flack jackets (with heavy *ss ceramic plates) etc etc. It all adds up. 100 rnds of 7.62x51 is approximately 7lbs. It might not seem like a lot until you add it all up. Plus you can't just snap the belts together like they do in the movies.... dirt and stuff gets in between the rounds and they would get caught on everything else hanging off your flak. The actual bandoleers come in cardboard boxes that are in small canvas bags with a long strap (believe me, you don't want to have to run with these things dangling from you), and two of those boxes come in a can. So, you either jam a bunch in your pack, put them in a pouch that clips to you, or you have to choose between hanging bandoleer off your body, or carrying a can (the last two are not really viable options). Yes already these obstacles are overcome, but you can't just load down a bunch more people with even more ammo just to have more machineguns.... there are also grenadiers (riflemen with M203s, or the new cylinder 203 launcher... I forget the name), plus your assaultmen that carry SMAW rockets, your SAW gunners, and your riflemen that carry AT4s rocket launchers.
Sorry for the rant, but already there are a lot of back and knee problems caused by the new flak jackets (that are a $100 million waste of money b/c they are heavier than the interceptors were and are already being phased out). All the nifty weaponry and high speed gadgetry may look cool and sound cool, but it don't make a bit of difference if you can't carry it, or can't maneuver with it (the M240 is 49 inches long..... the last thing you want is even more people trying to maneuver through a house with one).
All that said, I agree with being a 7.62 fan. Perhaps the MC will eventually listen and field 7.62 RIFLES that are magazine fed.... instead of the crappy M16/M4? Oh and buy the way.... before any M16/M4 lovers jump on me..... I have seen them fail/jam several times in combat (ie during firefights); to include my own. Gas piston is the way to go....... tiny q-tip size gas tube...... not so much.
Yup,I worked as small arms repairman in the 80s.the m16 etc gas tube is the weak link.only way i knew to clean it good is removal. and solvent, compressed air blown through.A clean fresh gas tube will fire 40 60 rounds of blanks before potential jam.them dam blanks aint no good for em.dont ever stick a qtip in the bolt end of the tube,just plug up faster as you shove carbon further into the tube.