Color me skeptical...
I would have to actually be there to shoot some of the loads before I am going to believe that, as those did not appear to be full power loads.
Not even close.
In fact I used to load some hot 360 grain .45 Colt loads that recoiled significantly harder than that in my Blackhawks.
I have to agree, particularly the loads the old guy at the end shot in his yard. That looked more like hot 45 Colt at best. The loads may be in 454 Casull brass, but certainly don't seem to be full power 454. Obviously lighter recoil makes that task a lot easier to do fast.
To the earlier question of what a full power 454 Casull is - a revolver that size (roughly 6"-8" barrel) can push a 300gr XTP to 1,600 fps.
