View Full Version : Bottlenecked muzzleloader chambers.

Nickel Plated
February 15, 2012, 03:10 AM
Hey guys, I'm currently designing a custom revolver cap n' ball rifle. Maybe I'll even build it some day but right now it's just a bunch of wishful thinking in SkechUp. Anyway part of my design is the chambers are bottlenecked. They are 9mm chambers that neck down to 7.62 and are 55mm long.

So I was wondering why noone makes muzzleloaders with bottlenecked chambers? I know most muzzleloaders are supposed to be replicas of historical firearms that were around before the idea of bottlenecking. But why do the modern inline MLs not use the idea?

Hawg Haggen
February 15, 2012, 05:33 AM
Because it's difficult to get a compressed load with a bottleneck. The 44-40, 38-40 and 32-20 were bottlenecks but not much of one.

February 15, 2012, 09:20 AM
What's a revolver-rifle?
If you want to do it the old way, do it the old way.
Don't? Go modern.

February 15, 2012, 09:53 AM
What's a revolver-rifle?
If you want to do it the old way, do it the old way.
Don't? Go modern.

There were revolving rifles/carbines in the Civil war "the old way". Now Rossi and H&R/NEF have revolving carbines in .410/45 Colt. The "modern" revolving carbines are an innovative concept based on modern and "old way" designs. I think that's what Nickel is going for with the bottleneck concept. Nothing wrong with that IMHO. I have an open mind.

I think a bottlenecked muzzleloader is an interesting concept but agree with Hawg that if you need to compress the powder, it could be problematic. Or are you talking about making a smokeless powder muzzleloading revolving rifle that doesn't need powder compression? That could be dangerous.

February 15, 2012, 10:17 AM
Another thought:

So I was wondering why noone makes muzzleloaders with bottlenecked chambers?

What do you suppose would be the benefit of it?

Wild Bill Bucks
February 15, 2012, 11:45 AM
Is there going to be a clean out opening under the percussion cap for each round in the cylinder? If the back end of the chamber opened for cleaning it would be alright, but if you have to clean from the muzzle end, I would think it would be a bugger-bear.
I have a pretty open mind to trying anything that creates an improvement in accuracy, velocity, or dependability, but
like others, I don't see any drastic improvement here. Am I missing something?

Nickel Plated
February 15, 2012, 01:17 PM
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? :p

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. :D

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.

Ideal Tool
February 15, 2012, 11:39 PM
Hello, Nickle Plated. Your going to have the same problem the black powder ctg. guys are with compressing powder in a B.N. case...when your ball or bullet is seated..only the straight line column of powder underneath is being compressed..the "sides" are not at all. Are you trying for higher velocity by using larger powder space under a smaller dia. bullet?

Nickel Plated
February 16, 2012, 02:06 AM
Yea that's basically what I'm trying to do. I guess i can try the bottlenecked cylinder and if it doesn't work, then I can easily make a regular straight walled cylinder and swap it out. That's all if I ever build the thing.

Another interesting thing about my design is it's a break-top. So instead of sitting there reloading the cylinder, you simple break the gun open, pull the empty cylinder out and insert a fresh loaded one. That's if you have several loaded cylinders, which I think many cap and ball shooters do. The gun will also have a regular loading lever like your typical C&B revolver for loading it.

I was also going to make a system similar to the Nagant revolver that pushes the cylinder against the forcing cone to close the cylinder gap and increase muzzle velocity, but scrapped that idea as just being too complex. Especially on a gun that shoots dirty black powder, that thing would probably foul-up to the point of jamming after like 6 shots.