8.3 gr will be only .177, in a country where most airgun hunters swear by .22. Even at our UK limit of 12 fpe, an 8.3 .177 will make a helluva mess of a target at any reasonable hunting range, say 35 yds or so. If you check out a ballistics calculator, it is surprising how little power you need for a humane kill at moderate ranges. Sure it's good to have unlimited power at your disposal, either with air or .22lr, but when it comes to the crunch, for small game or vermin at "sensible" ranges, the more modest of the "adult airguns" are more than capable. Compare it with the 450hp v8 auto. Nice to have and drive and a helluva buzz, but how often do you honestly need it?
Not looking for a deep discussion, just trying to point out how little power is really needed to dispatch small game/vermin in a humane fashion. If you have excess at your disposal, by all means use it, but calculate a little before thinking "it can't be done".
