I don't see much discussion on heavy rifle configurations. I'm curious, what are competitors running for barrels (manufacturers, profiles), barrel lengths, handguards and stocks in the heavy rifle division using a large format AR?  I'm mostly interested in the barrel info.

Haven't done any comp shooting yet from those that I know that have and videos I have see they all go for the lightest weight that they can. Less weigh the quick and easier you can move.

A: He's talking about heavy division rifle. IE: 7.62/.308 AR-10 platform rifles.

B: Not everyone wants super light rifles. They are quicker to move, but are not as stable on target.

Let me ask the same question a different way: would an AR-10 using a 16" 308 Ballistics Advantage Hanson SS barrel (heavy profile) and SLR Rifleworks 15" Helix MLOK lightweight handguard on Aero Precision receivers be a good 3-gun heavy rifle? Trigger to be determined. The rifle will also be used for hunting and as a precision rifle out to 600 yards.  That's my plan.

Sounds like a fine combinations. How heavy do you want to go, do you have a weight you're shooting for?

No specific weight goal. I have 6.5CM build with a Balllistics Advantage 22" barrel and that thing is a beast so I'm looking to comparatively shed some weight.

My quick reading of the 3-Gun rules shows no regulations regarding barrel length or rifle weight in heavy rifle division.

Sounds like a good build. what distance do the 3gun matches near you go out too? I have some that can go out to 600, but the farthest I have shot at a match is 450. A 16" .308 barrel would do very well at that range, or even out to 600.

Most of the ranges near So FL (Homestead, Okeechobee, Malabar), within a few hours drive, are limited to 600 yards. Public ranges are 100 yards max.  The newish Altair Gun Club, east of Naples, has room for LD/ELD work but I'm unfamiliar with the facility and its matches. I have asked those who know about the typical Altair 5.56 and .308 3gun distances. I really need to get out now that Florida "winter" is approaching.

Not sure where you are in FL, but Manatee Gun and Archery Range (near Sarasota) has a outdoor range the goes out to 1000, so you'd be able to figure out your DOPE.

I am near a major metropolitan city in southeast Florida.

FWIW, I think someone told me Altair has a range that goes above 1600. Not sure though.

There are 3 ranges that go out to, or beyond 1000 yards that I know of in Florida. Altair, Manatee, and St Augustine.

Mine is as follows
2A Armament 5R pencil/taper profile 18" Rifle gas barrel
Jerry Miculek Muzzle brake
SLR Ultralight 16" handguard
SLR gas block
Aero M5 receivers
Geiselle High Speed Match Trigger
JP SCS buffer
JP VMOS aluminum BC
POF roller cam
MFT stock
POF buffer tube
TRS 25
About 7 - 3/4# empty, just over 8# with optic.
Kicks about like a 6.8 while shootin full powered 308.

I thought I wanted the 18" barrel to get the blast as far from my face as possible, but 16" would be just fine.  It is still rather concussive, but bearable.  You got to remember the recievers are longer.  16" handguard is a waste of length for the same reason.  
18" rifle is soft, but with the recoil of 308 you would see little difference with a 16" midlength.
Pencil profile is TOO LIGHT.  Mine really needs more weight on the muzzle.  It is quick for up close.
If I had to do it again, I would pony up for the JP with the heavy profile up front for weight and just sell a body part to pay for it.  What I have now is not accurate enough to hunt with unless I put a silencer on the end of it for harmonics.

Another idea I had was to just start with a DPMS Gen II 24" hunter.  Chop it back to 18" and flute under the handguards or just turn it down to .75" or .80" under the handguard, add a JP SCS, High Speed Match trigger, preferred stock, and adjustable gas block.  SLR and MI have GII handguards.  Then enjoy the lightweight and compact form factor.  I was unsure of this platforms future so I just built an M5 instead.