OK I know a few people have been wondering when Id chime in on this gun thread.
Best Battle Rifle (in general):
First the M1 Garand in 30-06. Sorry but the deficencys of this rifle are hard to ignore. Its true the weapon was lightyears ahead of the bolt rifles arming the other armys of WWII, such as the the K98. But it was mearly the bridgegap between the rifles of the late 19th/early 20th century and the modern stamp weapons that came on line shortly after the war. Also 30-06 rounds are to long and heavy to be carried in any kind of significant load by todays standard, great for aim shooting but you run out of rounds quick with menuver doctrine. Plus that little problem of using clips and not being able to top off the weapon, thats just not good. Combat Loading is taught by any good tactical (good god I used that damn word) shooting school. This weapon would have you use 7 rounds in one fight, and walk into the next with 1 ready, you may as well just shoot the round off in the dirt and load because your not gonna get through a fight with a single shot, lest you be a much luckier man then I.
Second the M-14. While it makes up for alot of the defficiencys of the M1 such as going to the .308 which shortened by 1/2 inch (12 mm), kept the original ballistic properties due to modern propellants used. This made carrying ammo loads easier and lighter and up'd the round count of the individual soldier enough to allow for a bigger volume of fire. However the weapon was to light for its caliber (despite what you may think after humping one 15 miles in the sun). Rapid fire and burst was just impossible to control at any range that could actually make it worth while. It was mearly a modernized M1, but not modern enough with its competition at the time. Vietnam due to its enviroment pointed out weapon deficencys quickly, many point to the M-16's fickleness to any sort of dirt/grime/humidity, but The M14 was too long and too heavy to be carried all day long in hot and wet jungle. Great, and I mean just wonderful percision marksmens rifle, but not suitable for standard infantry use.
And the Winner Is (IMHO)
Heckler & Koch G3 series
For a .308 "Battle Rifle" no other weapon has a better record of excellence. Inspired by the Spanish CETME it has served with more then 50 countries (including ours unofficially) in the last 40 years and continues to be manufactured by Greece, Pakistan, Iran, Turkey, Portugal and others. Why this rifle (and not my beloved FAL Im sure A4 is wondering)?
1. Durability. For a modern .308 battle rifle there are really only 4 guns on the list, the M14, FN FAL, AR-10, and G3. The M14, we went into, and the AR-10 has not recieved any sort of support as an actual military weapon more a hey look what we did. Now why no the FAL, because the G3 contains fewer parts and combined with the precision of its high quality german engineering just performs better and is easier to take care of. Its simplicity also makes it cheaper to manufacture then any of the other rifles listed (Even if we are familiar with H&K prices and dont believe it).
2. Accuracy and Usability. H&K did a great thing when they came up with the roller delayed blowback action for this weapon. The delay made up for the defficiancys encountered by the other mainstream .308 rifles that being that the kick was to much for the average soldier to deal with limiting the ability of that soldier to put alot of rounds on a target. Also its capacity over older weapons like the M1 allow it to keep going a little longer.
3. Versatility. The weapons come standard with a claw mount that will accept a variety of optics allowing a standard rifle to quickly be made into a percision rifle. Also a bipod can be fixed and drum mags are available to allow for effective use of automatic fire in a light machinegun role.
My one complaint, get down in the prone position as a left handed shooter and try and charge the weapon, that and its civilian price are the only reasons I have a FAL and not a H&K 91.