Yes, some very impressive speed there. There are Canadian shooters in the sport that are that fast given the same target size & distance setting.
If you notice the rifle targets shown in the vid are 15 yrds or less and of very generous size. Guaranteed, any of those guys featured won't shoot that fast at an old fashioned cowboy shoot such as a Med Hat skinny tube shoot or Carmichael Sask. shoot where the rifle targets are 50 yrds away.
While caliber & load strength will regulate speed, target range & size will/ can have a more regulating effect.
And remember, those are the $2000-2500 (or more) very highly tuned 73's That B.C. talks of in the other cowboy thread going at this time.
I didn't have much luck trying to go that fast...poked the trigger thru my finger when I closed the lever before getting the finger out of the road...and that f#%%$n hurts.