Towards the end of November 2020 a friend of mine made a useful shooting target out of a decommissioned steel services cupboard. The new cupboards are plastic, so there are several of these metal ones knocking about if you know who to ask. Anyway, he gave me a cupboard and left it for me at the shooting range on 2nd January 2021.
On Friday just gone I was able to go and pick it up as the shooting range reopened. I finally put it up today. I had thought about it as I realized it was heavy and the door only opens about 120°. This would put stress on the fixtures that could be a problem.

So the door has been removed and the pellet catchers are held in by strong magnets and supported with wood. I’m going to change this and insert some hooks. I’m going to fashion a lighter door from MDF.