You might be interested to know that in many states, black powder guns aren't legally considered firearms. None of the legal hassle that comes from buying a gun, and they tend to be cheaper too. People on parole sometimes get them for self defense. I know it might seem silly of me to suggest a Big Iron, but six shots is better than none.
I own a musket for home defense, since that's what the founding fathers intended. Four ruffians break into my house. "What the devil?" As I grab my powdered wig and Kentucky rifle. Blow a golf ball sized hole through the first man, he's dead on the spot. Draw my pistol on the second man, miss him entirely because it's smoothbore and nails the neighbors dog. I have to resort to the cannon mounted at the top of the stairs loaded with grape shot, "Tally ho lads" the grape shot shreds two men in the blast, the sound and extra shrapnel set off car alarms. Fix bayonet and charge the last terrified rapscallion. He Bleeds out waiting on the police to arrive since triangular bayonet wounds are impossible to stitch up. Just as the founding fathers intended.
I assume this doesn't include black powder cartridges? Still not bad though you can go for a cap and ball revolver which gets you 6 shots before you have to take the next 10 minutes to reload.
everybody gangsta til i break the blunderbuss out. and you know i keep that shit loaded. i can drop a ball on an aggressor in 2 minutes flat. try me bitch (just give me a little bit of a headstart tho)