I stopped hunting a few years back now, I’ve tried .22, HMR and FAC Air (under supervision of a ticket holder) but my own hunting was always sub 12ft lb air mainly PCP but also with springers.

I’m not bullshitting here (and I may have been lucky rather than skilful) but I never had a runner during my hunting days. I didn’t take a shot many times as I didn’t feel 100% and I’ve clean missed the rabbit a few times, but I’ve never hit a rabbit and wounded it. 99% was .177 the rest .22.

In my very limited experience if I stayed within my limitations / ability and didn’t take chances where the odds were against me then sub 12ftlbs was enough to produce a clean and humane kill.

I struggle now with shooting and fishing in terms of ethics, so go cycling instead