I gotta say, the 1K mark might be a little low... the main reason is, there is no "Mil-Spec" benchmark for Large Frame AR's

Unlike your listed FAL, M14 (M1A) and HK 91's the various 308 AR's can't even agree on parts commonality. And your listed firearms are all battle proven.

You can see what I mean.

With that said... given most 308 AR's are built out of the same materials as a AR15, I'd like to think the 308's could handle a good deal of abuse... BUT, I would add certain parts to help the 308 AR handle the larger caliber abuse of the various parts.

And frankly I think most all manufactured 308 AR's could stand to be less gassy... regardless of brand.

Add An Adj. GB for sure.

Add A heavier buffer weight and recoil spring strength.

And some QC on your end, on the 308 AR right out of the box.

IMHO, the PSA PA10 has all the parts for a solid foundation, and is a bargain.

But, by the time you add the above parts, you might be over 1K and then some.

https://palmettostatearmory.com/ar-10/pa-10-complete-rifles.html

Adding those parts will slow the cyclic speed ( just by milliseconds ) , be easier on the various parts, allow easier reliable extraction, allow easier follow up shoots, and be easier on you.

I now have 9 PSA large frames... and while I wouldn't say I have run them through a ringer... I am pretty abusive at the bench, firing hundreds of rounds in a day, with no cleaning and no cool down. I think my highest round count PSA is right around 1500 rds through one of the .308's .

Anyway , out of the 9 PSA's ( 308's and 6.5CM's ) and many thousands of combined rounds, I have had no parts breakage, and the PSA's have run like clockwork after a normal 20rd break-in.
I do lube the BCG routinely...
And watch for anything out of the normal... ( haven't seen anything yet )

Back to the QC... polish the feed ramps, thoroughly clean the chamber and bore prior to firing, check that the parts are all snug, and check the buffer assm. for the proper carbine length parts ( from PSA )

If you are comfortable doing those QC items ( I am ) then I think you'd be happy with a PSA.

So... I guess I don't know if a 308 AR could "best" battle proven rifle... but I do know, I wouldn't hesitate to grab any of my PSA's if the poop hit the fan. I most certainly have that amount of confidence in them.

My 2 cents may not be the info you are looking for.... BUT... I will add, my PSA's are significantly more accurate then ( and hold that accuracy when dirty ) my M21... I can shot many hundreds of rounds out of my more precise PSA's , then without cleaning, fire a danged good group with match ammo.
Even if I just clean the bore... precision from a AR can amazing after hundreds of rounds.

I cannot say that about the various other 308 battle rifles.

I could certainly never say that about my M21... 150rds, tops, and you need to take apart various parts and clean them up thoroughly ( gas piston ) , clean the bore, mess with getting the bolt out of that tight ass charging handle.

In other words, it takes a ton more effort to sustain its level of precision in my M21 v. the 308 AR.

@sierra80mk , @KTM300XCW

YMMV.... but... DC Machine makes their barrels. I will add... my PSA FN CHF CL 20" upper is a hammer . Shooting great with everything.

https://www.ar15.com/forums/industry/PA10-Nitrated-18-Gen-2-observations-fixes-Criterion-barrel-results-10-Sept-17-/301-284190/

https://www.ar15.com/forums/industry/Current-Production-PA10-s-308-and-6-5CM-rifle-reviews-and-compared-to-1-year-old-PA10-Gen-II-s/301-288436/

https://www.ar15.com/forums/industry/PSA-PA10-GenII-lower-w-PA-65-review-START-at-the-beginning-again-UPDATED-with-Tn-G-results-/301-285762/

I will try to repost photos later...
Here is 20rds DAG

7rds FGMM 175gr

Remember, as posted in the various linked threads... I am a FIRM believer in the Adj. GB, heavier buffer weight and firmer recoil spring.

I also FIRMLY believe in truing / lapping the upper receiver face. IMHO, it is worth the added effort and results in more consistent groupings.. ( less flier's,and tighter more consistent groups )

I believe in both so much, I have done it to every large frame AR, I've built and or own.

And before someone chimes in and says ... "shouldn't this stuff be already done at the factory"

Remember I said the PSA's are a solid foundation... and the price is for a functional .308 sized AR... but the added finessing will make the firearm FAR more pleasant to fire, and is easier on the parts.

There are many more details.. so read the linked threads..  and then if you ( or anyone ) has questions, I will answer as best I can and offer additional input.

In the end, you will have a very soft shooting Large Frame AR.

Everyone that fires mine says the same thing... " I was expecting more kick" , followed by "that isn't bad at all"... all the way from 105lb girls and boys through 6' 4" 280lb men.

My PSA based upper with FN 20" CHF CL can do this  ( when clean ) ... 10rds 155gr Horn. AG ( Solid foundation aspect )



And my Criterion barreled PSA 6.5CM upper can do this when clean... 10rds Horn. AG 140gr ( Again ,Solid foundation aspect )



I don't shoot like this everyday... just sayin', but who wouldn't have bragging rights with those groups, Lol

And the 6.5CM linked thread shows what a Factory PSA barreled upper in 6.5CM will do. Also IMHO outstanding performance from a bargain Large Frame AR.