Hawg Haggen: Those are cartridges though. I'm making a muzzleloader where you just pour the powder in, and the chamber itself is bottlenecked. Though same concept I guess.
Rifleman1776: http://en.wikipedia.org/wiki/Colt_revolving_rifle That's a revolver rifle. And my main inspiration. Reason I'm doing this is because I want to do it MY way. And because I just enjoy designing things, why not?
noelf2: No it will be a black powder gun. I may not be John Browning or Mikhail Kalashnikov, but I have read enough to know that smokeless powder doesn't like working in muzzleloaders. Even in one designed to stand the pressure it just doesn't work well outside of a sealed cartridge.
On your other point, I think it would allow you to get higher velocities. The whole idea here with the 30cal bullet is low-caliber, high-velocity muzzleloader. Sure you can just pour more powder into a regular ML, but from what I read you eventually reach a point where the powder stack in the chamber is just too long and thin and thus the bullet leaves the barrel before the whole thing burns off. Leaving you with alot of wasted powder that doesn't do any work. In a small caliber bore, you would reach this point very quickly. I am under the impression that with a bottleneck you get the same high volume of powder but in a shorter, fatter stack that burns faster without having to increase the caliber of your bore.
The other benefit of course is that it just sounds cool.
Wild Bill Bucks: The back of the chamber will be bored completely through with a plug screwed into it and the nipple screwed into the plug. That way you can simply unscrew the plug to clean the chambers. Can also be used to unload the gun ( open it, pour out powder, ram ball all the way through the front or back) or for a do-over if you seated the ball and forgot the powder or accidentally rammed the ball past the bottleneck (though the loading lever is made to help prevent that).
As for compressing the load, I think that if you pour powder all the way up to the bottleneck where the bullet sits then the bullet should compress it fine. If you want a lighter load, then pour what you need then top off the rest of the chamber with cornmeal or whatever you use and compress with the bullet as usual. Guess I won't know for sure if it works and what the benefits are until I build and shoot it. Worst case, there is no benefit and I'm just left with a weird unique rifle. That's fine with me.