I just saw this posting on another site. The rifle in the video is chambered for a 14.5X114 necked down to .50 cal, shooting a Hornady 750gr .510 A-Max.

https://marchscopes.com/news/10738/


The presenter says the recoil is much worse than a 50BMG rifle, and that means I do not want to try it as I do not like recoil. Yes, I am a wimp, but that March Genesis scope isn't.