Larry Gibson
posted this
18 September 2018
MaverickNH
I've a 50 cal TC Black Mountain Magnum which is a "traditional" ML made for saboted bullets and up to 150 gr (3 pellets) of pelleted BP substitute powder. It had a 1/28" twist. Right after I got it to use Oregon banned saboted bullets, required a lead ball or bullet (not more than 2 caliber lengths) and granular powder (Real BP or substitute). I then tried various different kinds of bullets and didn't find one that really utilized the rifles potential until I tried the Maxi-Ball. I cast mine using an original TC mould but ones cast from a Lyman mould do just as well.
After a bit of testing I settled on Triple 7 FFg. It proved to be an excellent powder and clean up is super easy with just water.. I use speed loaders when hunting so with one down the pipe and the 5 speed loaders that is sufficient.
1. Where can I get 50cal slugs to size my barrel?
I never bothered slugging the barrel on min. The Maxi-Balls "as cast" of 16-1 alloy (needed to hold up to the magnum level velocity) fit perfectly and load easily. The bottom bands are a tight slip fit and I use a short starter to start/engrave the top band. The rod then easily seated the bullets on the powder charge.
2. Are there sizing dies for 50cal bullets?
I think Lyman makes H7I dies but I've not needed them.
3. I see mention of Walters Wads over BP but they list 0.512 - is that for 50cal?
I cut my own "wad" using some store bought (fabric store) felt (about 1/16" thick) and soak them in my own lube. The wad cutter can be made or bought.
4. I use Hi-Tek Supercoat on my pistol bullets - useful for ML bullets?
I use a BP lube made of 5 parts beeswax to 4 parts olive oil. It's what I make for my BP cartridge bullets. I hand lube them lubing only the bottom lube groove.
5. What’s a good mold to start with?
As mentioned I use an original TC Mould but have found Maxi-Balls from a Lyman mould do just as well.
6. What lead alloy to use?
I originally used pure lead but quickly found it is too soft for magnum loads. I was using 16-1 for use in my TD 45-70 bullets which is the alloy Springfield Armory settled on after extensive testing backing in the 1880s. It was holding up quite well to velocities of 1500 - 1600+ fps in the 45-70 so I tried it....instant success.
I worked up to 90 gr (V) using the FFg Triple 7 and got excellent accuracy with a velocity of 1550 fps. Using FFFg at the same 90 gr (V) also gives excellent performance at 1575 fps. The 16-1 alloy also expands extremely well in game. Below is a 100 yard target shot with 6 shots fired as fast as I could load and shoot from a bench. The first shot loaded down a clean barrel then the other 5 loaded and shot with out an cleaning or wiping of the bore. The 6th shot loaded as easily as the 1st.
LMG
Concealment is not cover.........