This question comes up all the time, and every time I mentally go through my guns, pondering what I'd get rid of if faced with such a tough decision. Problem with the premise here (one gun, one caliber) is that it's gonna be compromises. There's just no way around that. So we're really asking what is the gun that we consider the best compromise for our particular uses. For me, I think it would be the Veteran .20 that I'm always commenting on. It's already my general use airgun, but with the 13.73gr JSBs @ 800 it's field target legal and capable of being competitive. And with the 15.89gr Heavies @905-915fps, it is accurate enough to be a viable long range option, for paper, pesting or potentially Extreme FT.
Lots of people saying Veteran in the previous to mine comments. That didn't surprise me. There were also a couple proponents of the .20, which DID surprise me.
Hopefully I'll never be faced with this situation, cuz I'd sure miss the more specialized guns that I enjoy for the above stated uses, as well as not mentioned uses (like the FWB300s for offhand fun, the HW50s for outdoor springer fun out to 55 yards, and the newest in my collection, the 1720t for low power garage fun).
Compromises, compromises.
