Quoted:
I don't know about 500 yards, but the guy that one 2011 Texas NG Rifle Match was using a M4gery with ER Shaw 16 inch M4 profile barrel at a maximum of 400 yards.
2012 winner last weekend was using a Colt M4 equipped with a 4x ACOG, again maximum of 400 yards. Most competitors were using 20 inch A2/A4 rifles.
I know its not 500 yards, but I know they can run head to head and even prevail at 400 yards with M855 ammo.
I do know that it is sooo much easier to hit at 400 yards with a a good .308 than with a .556.
Yeah, if it'll hit at 400 with m855 it'll sure as hell hit at 500 with sierra match kings and/or hornaday 75 grain bullets.
Like I said, my A2 would remain my primary 500 yard match rifle, but I figure FTR with an M4 decked out as seen above would be fun a few times.
ETA: My ten year forecast is a Colt 6920 (M4 carbine marked) with a 13.2'' LaRue rail, bipod, and a 4x acog model up top. And maybe even a micro aimpoint at an angle on the side. I'd probably go with a sopmod stock (or whatever gives me the best cheek weld, I hate standard collapsing stocks) and definitely a geissele SSA.
Then after that I'd get another 6920 or maybe a 6933 with an aimpoint and a weapons light for home defense and call it good.