Do any companies out there sell remakes of the old turn of the century big game double pistols? Id love to own a double pistol and im not talking an over under derringer im talking a full sized side by side pistol.
I guess you mean a 'howdah' type pistol . Unfortunately , the only thing that I can think of right now is the Cobray .45 LC / .410 side-by-side derringer . They did make one with 8" +/- bbls . It could be customized with a larger grip frame ...
Howdahs were double barrel because nothing was available to provide more than one shot in those days.
If you want massive in a handgun, you actually live in the Golden Age of modern Howdahs. Start with the Judges and work your way up to the .50 AE Bowen Alpine. THey used to make the full 500 Magnum in the short Alpine, but it really wasn't user friendly. I broke a frozen finger clean one fine February morning. Ouuch.
Many of the old Howdahs were 20 bore or 16 bore. Any cartridge handgun today over .500 inch is considered a destructive device by the BATFE, if i recall correctly, so you'd be limited to a half inch bore howdah unless you wanted to pay the fees and jump through all the legal hoops.
Now, if you wanted to do that, just get a Class 3 manufacturer to take a 20 gauge side by side shotgun and cut it down, pistol grip it, and put threaded choke tubes in it. That would create a "Paradox"-style Howdah and you could shoot shotshells or cartridges through it. Magtech manufactures modern 20 gauge brass hulls that take pistol primers and a couple manufacturers offer molds for slugs. That would be a sweet pistola, for sure!
If you wanted to avoid the paperwork, just get a side by side rifle in 45-70 (Pedersoli makes a nice one) and have it chopped. Plenty of poop there.