Building a smokeless Muzzleloader

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Feb 16, 2009
My question is kind of a 3 fold explaining inquiry. I have built from scratch 3 of my own custom .50 muzzleloaders, 2 flintlock, 1 percussion, and enjoy using them quite a bit. I have an idea/ Savage's 10 mlss has really caught my eye. to build something on that order for N.Y. - and I have acquired a T/C contender barrel in 44- 40 that sound's like a great foundation to start on. so here's the questions,:

1- can I use powder/ bullet combos designed for the 44-40 cartridge.
2- do I just breech plug it for a 209 primer or lpp, or do I need to install some sort of a casing substitute, maybe out of annealed soft steel?- (does the brass case provide some sort of strength that a steel breech plug wouldn't
3- further.. what makes one t/c barrel ok for .44 mag, and another just for 44-40- hardening?
4- I am thinking of crowning the muzzle for a 11 degree cone angle and using real(rifling engraved at loading alox lubed lee) style bullets = or a bevel base
5- I know I need to keep from pushing the bullet to far into the chamber area and out of the rifling so my breech plug/or casing substitute must be high enough to prevent that-

any experience advice appreciated.
1. Maybe.

2. A brass case is not nearly as strong as the steel barrel, chamber or breaching surrounding it on all sides.
All it does is expand in the chamber and provide the pressure seal in the open breach design that prevents high-pressure white hot gas escaping through the cracks and taking the action apart like a cheap billfold.

3. Nobody is privy to that information except the design engineers at T/C.
I would have to assume however, that they do not make all the smokeless barrel out of ordinance grade steel, and the muzzle loader barrels out of cast iron or something in this day and age.

But thats just a WAG!

4 & 5. Check to make sure the thicker chamber area of the cartridge barrel is not all used up by your breech-plug threads.
Which would put your Max chamber pressure further forward in the tapered section of the thinner barrel.

I didn't condone it, or say it is safe, as like I said, thats just a WAG on my part.

Most all modern firearms use high grade barrel steel. The problem is that when you use BP you're operating within pretty narrow pressure confines by its very nature. Whereas with smokeless the variables go from puff loads of Trail Boss at 10,000 psi to magnum loads at 65,000 or more psi. And the difference is hard to track.
I would use the 209 primer; ordinary percussion caps like the Remington 11 often won't ignite smokeless powder.


Something else to consider is how deep you seat your bullet in the barrel. some loads are compression loads so the problem is not as great. But some loads have space in the case and the load takes into account this space and the added stresses that this causes. If you want to reproduce accuracy without the cases, the bullet seating is cristical.

Very tricky thing your trying, be very careful or you may wear thst rifle barrel!
There was a guy here who said he had done that.
Unfortunately, I never saw the gun in person and he is since deceased.
His DESCRIPTION was of a Remington Rolling Block normally barrelled and chambered in .44 Magnum with a chamber insert to hold a primer and allow muzzle loading.

Agree with Cosmoline, these days the only difference between a .44 Magnum barrel and one for .44-40 is the chamber. Few makers even bother with the .002" nominal groove diameter difference.
Smokeless Muzzeloader Update

To all those who found this article interesting and added their thought and advice, I bring news of update in this project. First off it turned out to be a huge success ..BUT I did heed alot of the advice and warnings and made 2 VERY huge game plan changes,:

1- First off I sold the 44-40 barrel and purchased a green mountain 45-70 grade 1 1/4" straight rifle barrel blank for the project (midway)- turned a taper and profile to it (full 1 1/4" at the breech for 6")

2- I decided to mount in to my stevens 180 hammer less 12 gauge shotgun receiver. Tapped it for a 1/2- 20 x 3/4" nf breech plug, bored for 209 primers (3/32 flash hole). Using reloader 7 and Lee's R.E.A.L. 260 grn bullets to proof fire it (string remote firing) I worked up to 53 grns before I quit as the primers began to deform really bad. I plan to run it at 40 grns

Next I have to drill and tap to mount the scope and then we will see how accurate she is!

I tried 2400 powder but at only 25 grns the primers started to rupture
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