12.7x44 conversion to 50-70 gov't
- Thread starter m1978
- Start date
Sized .50-70 will often fit, but need the rims turned down a bit... USUALLY. I don't know about the quality control there, I have had several and every one had a different chamber. The one I kept takes a sized .50-70 with turned down rim perfectly. One of the ones I sold took an UN-sized .50-70 with full rim. Yet another had a chamber that took the fireformed .348 perfectly. Never saw such widely varying chambers in my life.
talked to a gunsmith in ontario, who is apparently very good at this stuff, and to change over to 50-70 is a breeze, and the cost is negligible. seems to be the way to go. a little extra to mod for a vernier sight and i'm off to the races. looks like a lot of fun for little outlay in cash.
Just be sure to try a .50-70 case in it, first, as I said, some will take the case as is, some need the rim turned. I had my neighbour turn the rims down on some .50-70 cases, and they function perfectly. You have to remember, too, that the 12.7 bore is tighter than the .50-70.
My brother had one and it was my job to provide the ammo for the critter.
I just opened out .348 Winchester brass, trimmed to length and loaded with a .515 Bullet.
After it has been fired, it loads okay with my .50-70 dies I keep for my own Remington, so I didn't have to buy a new set of dies.
If you rechamber, you will have destroyed the originality of a fine old military piece. This way is MUCH better.
I just opened out .348 Winchester brass, trimmed to length and loaded with a .515 Bullet.
After it has been fired, it loads okay with my .50-70 dies I keep for my own Remington, so I didn't have to buy a new set of dies.
If you rechamber, you will have destroyed the originality of a fine old military piece. This way is MUCH better.
No. The bores on these Swedes are much smaller than that. A rechamber is easy, I've done several, but the pilot on the reamer needs to be turned down. Quite often you will be able to use .510" bullets, sometimes not even that big. Also remember that the twist rates on these are extremely slow, best results seem to be in the 350 grain range. Big bullets will not work well in the 49" twist they have.
Again, speaking from experience, the .348 brass can be waaay undersize in some Swede chambers. To be honest, I think their quality control SUCKED! I have owned some from Carl Gustaf, Stockholm, and Husqvarna and all of them had different chambers, but were the same calibre. They must have issued really soft, undersize cartridges to make up for the sloppy chambers. I have noticed that rifling differs somewhat, too.
In my Swedish Roller in 12.7X44R, I use Starline 50-70 brass shortened and with the rim turned down - many chambers require that the base diameter be reduced as well, so I was lucky. My bore has a 0.515" groove diameter and on these old guns that can vary, so must be measured. My gun shoots 425 gr cast very well, but not anything heavier - I suspect that it's the twist rate that's too slow. I use smokeless powder with 50-70 starting loads.
If my gun had been a sporter, I would have rechambered it to 50-70 or possibly 50-90 (which is more than just a lengthened 50-70).
If my gun had been a sporter, I would have rechambered it to 50-70 or possibly 50-90 (which is more than just a lengthened 50-70).
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i've heard the variation can be extreme. i guess if i'm buying it i should have the bored size checked so at least i can size down bullets, an oversized bore would suck. now, next question: where to get 50-70 brass in canada? also, is 500.00 a good deal for a sporterized one with a good bore?
