I want a short 6.5 Gas Gun

[Eurodriver]

I was at Arena Training Facility a few weeks ago, and a guy was running the hell out of a 16" LMT MWS in .308. He almost outshot me on targets out to 800y in some decent wind (I was using a hand built 20" 6.5 Bolt Gun) He was running a 4.5-32 NX8 (which was a bit too much optic, I'm planning on 2.5-20) I fell in love with that gun. It lacked the speed and BC to get reliable 66% IPSC hits at >1k, and there was obviously a good shooter behind it, but I think my next rifle will be a large frame gas gun. I've always dismissed them for several reasons.

First, a .223 will do almost as well out of a 20" gas gun as a .308 will out of a 16" but with much less recoil and cost.

Second, a bolt gun is always going to be more accurate than a semi-auto.

Third, large frame gas guns are generally heavy.

Finally, They aren't as "plug and play" as AR15s are, so I want a factory gun. But factory guns are generally chrome lined and generally speaking, CL barrels don't shoot as well as say, a .223 cut rifled Krieger. I know this doesn't matter to most of you, but I will only consider factory guns

This guy's LMT kind of erased points 2-4. For typical target sizes a CL barrel will be more than accurate enough, and with that short barrel it wasn't heavy at all. Recoil didn't seem much worse than a 6.5 bolt gun.

Questions:

Who makes a quality factory 6.5 Gas Gun in 16-18"? What models are available?

Is going 6.5 on a barrel that is 16-18" worth it over .308? I will most likely just shoot factory ammo out of this gun so caliber doesn't really matter too much. I know 6.5 blows .308 out of the water at 20" and beyond, but are the ballistics for a 16"-18" barrel much different?