The 45-70 is not available in a handgun. I would stick with the 44Mag or 45Colt. The 44-40 is a fine cartridge, but if you don't handload, it will be expensive to buy and hard to find. A 44 or 45 carbine woudl make a fine defensive weapon, inexpensive plinker, and a capable deer rifle at shorter ranges. I have a Rossi carbine in 45 colt, and it is a fine shooter. It is top eject, and some of the shells do hit me while ejecting, but it's no big deal.