If your choice of firearm is of a caliber that is used by law enforcement, the U.S. military/NATO or a military caliber from the old Warsaw Pact nations you should be able to find ammo. Every firearm I own falls into what I would call a common caliber/chambering such as: .22 LR, 9mm, .357 Mag, .40SW, .45ACP, .308Win (7.62 NATO), 5.56 NATO, 30-30, 30-06 and 12 ga. There's lots of ammo for those calibers in personal stockpiles. I should add 7.62x39 which I don't have, but there should be lots of ammo floating around. My personal stockpile is in calibers used for competition and plinking.

Why have cylinders chambered for calibers you are unlikely to ever scrounge? In a rifle chambering you need a decent barrel or as has been said the muzzle flash will be outstanding -- but where did the bullet go? This is a one shot device -- one shot. It needs to be accurate and I do not see that attribute anywhere in this "rifle".