Converting a Remington Rolling Block .43 Egyptian to a Muzzle Loader

[Snidely70431]

I picked up a Remington Rolling Block chambered in .43 Egyptian (AKA 11.43x50Rmm Egyptian) in rough condition to play with. If brass for this cartridge is available I was not able to find it, so I tried adapting it to 45-70 government brass, hand-loaded with paper patched .442 projectiles but that did not work.

Next I reamed out the chamber with a 37/64 drill (.5781) and threaded it to 5/8-18 (this is thread used in the breech plugs of many commercial muzzle loaders, Knight, CVA and Thompson-Center being examples). I made a breech plug for the 209 shotgun primer, but the Rolling Block action does not seal well and I experienced blow back. More successful was a breech plug using the .32 H&R Magnum cartridge, and that is where my experimentation stands now. I'll probably make breech plugs using .357 Magnum (which can also use .38 Special and .357 Maximum brass) and .41 Magnum brass. I like the 5/8-18 thread because commercial bolts are available from which breech plugs can be made without having to thread the bolt.

Rolling Block Receiver
Receiver Open
Receiver with .32 cartridge in place
Barrel with Breech Plug partially unscrewed, showing unmodified 5/8-18 bolt, tap and die.

 

[Snidely70431]

Hmmm. Interesting. I put pictures in here, but they seem to have disappeared.

 

[SC45-70]

Inlines that use 209 (shotgun) primers have very small flash holes in the breech plug between the primer and the powder, .025-.030 inch.
This helps prevent blow back past the primer.
If you press the primers into the breech plug you can use a bigger flash hole but if you want to remove the spent primers without a tool you have to use a small flash hole.
You may also be getting blow by past the threads on the breech plug and the barrel. Most modern muzzle loading guns have a small shoulder that the breech plug screws against to prevent blow by.
SC45-70

 

[JeffG]

Now THIS is interesting! Way to go!

 

[Snidely70431]

Inlines that use 209 (shotgun) primers have very small flash holes in the breech plug between the primer and the powder, .025-.030 inch.
This helps prevent blow back past the primer.
If you press the primers into the breech plug you can use a bigger flash hole but if you want to remove the spent primers without a tool you have to use a small flash hole.
You may also be getting blow by past the threads on the breech plug and the barrel. Most modern muzzle loading guns have a small shoulder that the breech plug screws against to prevent blow by.
SC45-70

No blowback past the threads on the breech plug. I converted the 209 breech plug to the 32 H&R Magnum.

I've had very bad luck trying to drill very small holes for the flash tube for 209 primers. The drills break, which ruins the bolt, because drilling past the broken drill is usually a nonstarter. A couple of times I did drill a small hole in a small bolt ad then threaded it into a larger hole in the breech plug, but not lately.

 

[SC45-70]

No blowback past the threads on the breech plug. I converted the 209 breech plug to the 32 H&R Magnum.

I've had very bad luck trying to drill very small holes for the flash tube for 209 primers. The drills break, which ruins the bolt, because drilling past the broken drill is usually a nonstarter. A couple of times I did drill a small hole in a small bolt ad then threaded it into a larger hole in the breech plug, but not lately.

Drilling small deep holes is a pain!
The 32 H&R (or any straight wall pistol case) should work fine as it should expand in the chamber reducing blow by.
SC45-70

 

[Snidely70431]

Drilling small deep holes is a pain!
The 32 H&R (or any straight wall pistol case) should work fine as it should expand in the chamber reducing blow by.
SC45-70

Yesterday I made a breech plug for a .357 magnum cartridge for the Rolling Block. In the past I made breech plugs for my break action inline muzzleloaders that took 32 H&R, .32 ACP, .357 magnum, 38 S&W, .41 magnum and .45 ACP, all using 5/8-18 bolts as startying points.

 

[Snidely70431]

The part I've had the most trouble producing for this project is the extractor, which is used on the 50/70 Navy, the Egyptian and Swedish versions. No fun at all making a usable extractor with a grinding wheel and files.