BSA Ultra single-shot.
A nice compact gun that isn't too heavy.
It's a bit hungry on air (about 35 shots per fill but doesn't take long to refill as it's reservoir is quite small).
It benefits from an upgrade to the silencer.
I'm not keen on the multishot as I've found the mags to be unreliable.
The unusual size scope rail means that you'll either need special mounts, or will need to swap the base clamp of the mounts.
HW100TK.177;Lightstream 4-14x44FFP. HW100TK.22:NVRS-F+doubler. Rapid mk1 .20:Lightstream 4-14x44FFP. SLR98.22:SR6NE 3-12x50IR.
Evo-T.177:SR6 3-12x44. Evo.25:SR6 3-12x44. TXHC.20:Falcon 4-14x44FFP. TXHC.25;WTC 1-5x20.