Depends on what he means by "consistent hits".
To be honest, an AR @ 850 is not a terrible platform and unbelievable. But that target size and bullet combo, along with the wind claims is where it gets into the fantastical realm. I have gone 90% on 12" steel @ 850 with my 24" AR Varminter pushing 69SMKs @ 3033fps, but never in the wind. Always on calm days. Throw an inconsistent breeze (3-5mph) in there, and my hit rates drop to 30%. Just way too much wind drift variation to be able to judge that.
3mph=27" drift
4mph=35" drift
5mph=45" drift
28mph=249" drift
29mph=258" drift
30mph=267" drift
A 1mph difference make an 10-11" difference in wind drift with a 69SMK @ 850yds.
My 50gr VMax load at 3300 is unreal.for wind drift. No way is it possible to make "consistent" hits on a 3" wide target at 850 in 28-30mph winds.
28=380" drift
29=393" drift
30=408" drift
I have never, EVER, seen a sustained consistent 30mph wind across a half mile flat field in the wild...