@scope007 I have not discovered a reason why they were faded out around 2020. I assume the Umarex Gauntlet was selling a lot of units and the RM8 just didn't have a market in the US.
A few guesses:
Under powered for a .22 and turning it up (e.g. pcptune's valve) reduced shot count.
Lot's had already run the fad of the850shop and turning the Hammerli 850 into HPA.
People wanted side levers and not bolt action.
They are heavy rifles.
I am disappointed in a lot of the US market when it comes to air rifles. Other consumers have different tastes than I do and the importers chase what sells (which I don't blame them for). Maybe it am just British at heart, but I sure wish there was a better way to buy guns from the UK