There are a bunch of Swedish rolling blocks rifles available chambered in this cartridge. They have new breechblocks and hammers, rotary extractors and firing pin retractors. And many of these barrels are in excellent condition. Would this caliber be competitive with lead bullets and black powder?

Swedish competition shooters used them. Many 12,7*44r had two breach blocks so they had both rimfire and central. 8*58r was a common moose rifle in the 1900-1950s.

http://www.walterborg.se/auktion/#/

Absolutely not; those Swedish calibers are not allowed; and you can't knock over a silhouette with an 8mm. Here are the NRA rules:
"Cartridges will be of the American black powder era, originally black powder loaded, manufactured prior to 1896, and originally chambered in American-manufactured rifles..."
Now, what you can do is use the Swedish action and re-barrel it to an American caliber.

The first 10000 m67 rifles in 12,7*42r (Close to50-70)was made by remington. then 20000 actions was made by remington and finished by CG/Husqvarna. They were later modified to 8*58r.

Vol, I have one of those very rifles, but I would think you would have some real fouling problems with black in such a bottle-necked case. That said, the 8.15X46 was one of the great schuetzen cartridges with black and duplex loads.

an interesting thought. Steve Garbe talked in his magazine a couple years back, about setting a HiWall up in 303 British. Don't recall if anything ever came of it though...

quote:

Originally posted by dpcd:
Absolutely not; those Swedish calibers are not allowed; and you can't knock over a silhouette with an 8mm. Here are the NRA rules:
"Cartridges will be of the American black powder era, originally black powder loaded, manufactured prior to 1896, and originally chambered in American-manufactured rifles..."
Now, what you can do is use the Swedish action and re-barrel it to an American caliber.

I must politely declare BS on that one!
The 8x58R is a Danish round that was designated m89 because it was first used in 1889 for the Danish Krag-Jørgensen rifle. From 1889 to 1908 it was loaded with 4.1gram~63 grains of BP under a jacketed 237grains round nose bullet for an "astonishing" 470m/s~1542fps.

Here is more than you want to know:



And as a gallery loading:


Here with smokeless and a pointed 196gr bullet:


I load it with the midsouth 8mm max bullet:

Dane-- you miss the point.To be legal for BPCR, the round must have been, among other things, chambered in a rifle of American manufacture and generally commercially available in America prior to 1896.

This is why you don't see some of the European calibers used in BPCR.

What Sharps said; you can declare all the BS you want but you still can't use that rifle in BPCR competition in the US. Which was the OPs original question.
Now, for local, informal shooting, sure it would be fine, but not for NRA competition events. Still harder to make bottlenecked rounds shot well with BP, although I do it with the 38-56 successfully.

That's good to know. I bought a dozen rollers to sell as BPCRs. But some of the bores are so bright and shiny it would be a shame to pull them. I think I'll set one aside with a good bore and one with a good action. That will be one to shoot as is and one to rebarrel in 40-65, 40-70 or 40-85. I'll post a couple on the classified section.