I have a Vudoo single shot br rifle, Anschutz 1907 prone rifle, and a couple of centerfire rifles that shoot one hole at 100y. Tuners, tunnel testing, hand pulled bullets, Lapua brass and match ammo, you know where that’s at. With my best lot matched ammo or handloads the one hole performance occasionally gets boring.
I have never achieved one hole anything airgun at 50y. At least not more than the odd occurrence. Wind is 5x more influential on airgun pellets than rimfire.
That Walther is a 10m match rifle that shoots at very low power. The Field Target model does 12 ft-lb (2x more) and will give up a lot at 50y to higher power airguns.
The only way to shoot small groups at 50 and 100 is with a very high power pcp and just the right slug and tune. Pellets just aren’t as consistent ballistically at those ranges. I’ve made some attempts to do this with my high power pellet PCPs and never got a consistently accurate combination. I will try again this year using an unchoked Benchmark barrel I have. And these airguns drink air and expensive slugs.
So the question is whether you’re set on 50 and 100y. If you can move the goalposts to 25 and 50 you can enjoy pellet shooting. You’ll come to appreciate one hole groups and good wind calls much more. There are guys I shoot with who did everything in firearms and have ignored all of it for 25-50y airgunning.