Converting a 12.7x44R (CF) to .50 Government (General)

by Mårten Wigardt @, Sweden, Sunday, June 21, 2015, 08:21 (1882 days ago) @ 762x51


I went out on a limb and bought one (1) shell case in 50-70 government just for the hell of it. I tried it and it chambered beautifully in BOTH my 12.7 Swedish RB's. One is Husqvarna and the other is Carl Gustaf. The only trouble was the rim. I bought 100 more shells and put them all in the 13 mm chuck of my power drill (again a very snug and nice fit), used a file and shaved the rim down to exactly 16 mm. Then I put them through my Lee loading equipment, with greased bullets and roughly 60 gn of powder.

I now have no trouble hitting the bottom of a Red Bull can (50 mm diameter) can at 50 meters and I haven't had a single cartridge refusing to chamber, although a few have required a little thumb assistance. It's a tight but easy fit, absolutely no gas leakage between shell and chamber. Neither of these rifles have been re-chambered and one of them is in pristine condition. All I did was take a little brass off the rim.

I used Starline 50-70 govt. brass as I don't know of any other. But in my experience these shells are far superior to the horribly expensive (3 to 1) Bertram Brass shells I originally bought. Also, the Starline shell won't buckle as easily as the BB shell.

I'm still surprised it worked since most testimonials have been to the contrary and recommending the arduous task of fireforming 348's.

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