I
Have ran since 178s through this rifle. It seems to group really well at 100yds. I was getting hit and miss results on steel past 800, that certainly could have been me. An interesting note on the 178s, with the new version of the AB app, it shows that a 178 ELD-X is marginally stabile with a 1-11 twist. I dunno.
Never shot the X as I don’t hunt with my rifle but the 178 ELD-M shot great in my last barrel in my .308 with an 11 twist so in the 300WM and the extra velocity they should be just fine.