Yeah, the Sam Yang would have the advantage of shooting arrows as an option too, but it would require a separate charging unit to have to upkeep.
If you had plenty of black powder on hand, or better yet could make it yourself, a flinter would be hard to beat as a dooms day gun.
If I knew I could hand make replacement parts for a hand pump, it would be a hard choice between going air power for the yang or black powder for a flinter.
You guys have my head hurting now.