Thanks again Jo for your ideas. For my zig zag slots, blowback cylinder, semi-auto muzzleloading revolver concept mockup, I think the limited weight of the cylinder
would allow it to have enough power for blowback forces to work fine with the zig zag slots system (ala Webley Fosbery) as in my mockup from earlier in this thread.......
But in reading some of your ideas Jo, I suddenly thought upon a rack and pinion gear system actuated by gas instead of a zig zag slot blowback, reciprocating harmonica block. I realized that a very large capacity harmonica block on a tripod mounted muzzleloader would be too heavy to rely on blowback to move the heavy harmonica block rearward and advance it via zig zag slots. That kind of system would be fine for a six shot revolver but not for one using a long, hi capacity, heavy harmonica block.
I realized that for THAT
kind of weapon with a very high capacity and heavy harmonica block, a gas piston or even direct impingement of gas to actuate an internal gear that would interact with a gear rack running along the length of the harmonica block to advance it, (a rack and pinion system actuated by gas) would mean the hi capacity, heavy, harmonica block would not have to move rearward and would be a much simpler and better system to use.
I did some more mockup work in photoshop. It's very crude but gives the general idea of what I'm seeing. Nothing like a picture to eliminate a thousand words.
Roller conveyor supporting high capacity, one piece, muzzleloading, percussion cap fired, harmonica block. Gas operated operating an internal gear that interacts with a straight gear rack along the full length of the harmonica block. This is just a very crude rendition and could be changed to suit the design. The supports for the roller conveyor are extremely crude. But you can get the general idea. In reality they would be very ornate Victorian, "Jules Vernian", "Captain Nemo" type looking supports. Supporting the weight of the long hi capacity muzzleloading harmonica block as it feeds and also exits the receiver.
Although I think gas operation would be a good method for this type of muzzleloading hi capacity harmonica block concept, you could also use a completely manual hand cranked system
instead of gas operation. As you no doubt realize, this would weigh a whole lot less than any Gatling and still have a high cyclic rate of fire but be completely a MUZZLELOADING
antique weapon not regulated under the NFA, instead of a Gatling which if it uses a cartridge the Gatling is regulated under the NFA as a firearm, although a Gatling being manually crank fired is not
classified nor regulated as a machine gun. With no gas tube on the barrel, that would enable a water jacket to be installed eliminating the necessity for multiple barrels for cooling......as in this mockup....
I appreciate the comments, thoughts and ideas. Keep them coming. Thanks.