these are not especialy popular guns in the UK.
Slugs are difficult.....
There are particular (and onerous)licensing requirements that most people wouldn't want to go through. Gaining a rifle licence is pretty easy and straightforward.
Having no very large game in UK, slugs don't really figure these days. Even when things were much easier on the legislative front, they were never much seen. In those high and far off times I used buckshot (Special SG) for fallow deer; now regardeded as all very unsporting and infra dig.
Have fun with the new toys.
Eug