it doesnt really matter what Daniel Horner uses, he’s gonna beat you.
Good point. 
While undeniably true, that wasn’t my point 
It seems like 308 rifles, and especially SR25/AR10 rifles have gained a lot of popularity and refinement lately. It seems like it was more driven my military adoption of these calibers over civilian desire. It seemed to me that the shooting organizations, perhaps unrelatedly, were trying to make the big rifles more competitive. More competition leads to more shooters, more guns, more accessories and that leads to innovations which starts a virtuous cycle. If you can shoot major on an ar15 platform I think a major avenue for optimizing the 308 guns goes away.
That’s all I’m sayin’.
the biggest problem is, only is USPSA does power factor come into play, other wise its just Divisions and Tactical Optics is DOMINATED by 223/5.56. Other than Rob Romero and a few other shooters(not sure if Jansen shoots HM now or not), most shooters run 223/5.56 in Tac Optics or Open. Tac Optics is the biggest division.
I wonder what he chronoed with that thing.
I was thinking of building a 300 blk after a local match last year and a friend of mine who has one. Really neat round. Here in CA I can’t get a supressor so I’d pretty much only shoot supersonic. I’ve been waiting for an 18 or 20" barrel to hit the market. If I’m going to go fast, might as well get as much barrel and velocity out of it as is practical. I’m hoping that’ll take some of the rainbow effect ouf of it… us mure civilians will have to wait for the longer barrels to hit the market if they ever do 
To make Major, he’d have to boot a 125 gr past 2560 fps.
The danger, if there is one, is another equipment race. A lot of shooters will ignore that he could have beaten them if he’d been required to throw rocks. They’ll hound their gunsmiths until said 'smiths build them a “match-winning Major 300 Blk.”
Still, an interesting way to make Major and gain points.
If the ranges are closer, and you want to easily make major, then 175 grain Sierra, 20.0 grains A1680, 2.245 OAL, Rem brass and primer. That is 55,000 psi and 1900 fps from a 16 inch barrel.