LOL. The Swede guns are chambered in two different calibers. one is a 12.7mm cartirdge - in these actions, only shoot black powder pressure loads.
The second batch were refurbed in the 1890's and later. They are chambered in 8x58RD. This is a relatively modern high-velocity smokless load. COTW list it at 46,412 psi by the older copper method. Modern straing gauge PSI would put that number even higher.
This means that the rolling blocks built between 1867 and roughly 1876 and re-case hardened in roughly 1891 to 1896 have been re-chambered to a round pruding pressure equivalent to average chamber pressure for the small ring Mauser like the 1896 Swedish Mauser in 6.5x55.
The story does not end here though...
In 1908 the Danes switched from compressed black powder loads to modern smokeless in their 8x58RD loads. This was a cartridge loaded with a 196 grain spitzer at 2,460 fps. This proved too powerful for some of the rolling block rifles, and a reduced charge load using the Dane bullet was developed for the rolling blocks ONLY. It used the same bullet but produced 1950 BAR, or 28,282psi.
what does all this mean? Basically it means that the actions from the 8x58RD are perfectly safe for anything up to 28,000 psi using the older CUP method of pressure measurement.
Trapdoor or "cowboy action" loads are designed to mimic Black Powder pressures, i.e. less than 18,000 psi. Any of these will be perfectly safe in a rolling block action - probably even the 12.7mm based guns.
Standard loads are designed to produce under 28,000 psi and should be good for the 8x58Rd actions. This is what I use in my example rebarelled for .45-70.
The hot marlin 336 loads SHOULD BE AVOIDED.
As for .45-90 or .45-110 loads, those cartridges should be loaded to black powder equivalent in ANY firearm. Neither was produced for modern smokeless.
As noted above, the later re-hardened actions have NEW hammer and breech block assemblies. They are made of more modern steels and are glass-hard. No need to bush the pins on these ones and they even have a built-in loaded chamber indicator that doubles as a gas port.
Re-barelling can be challenging on these. They are square whitworth threaded and there are some interesting cuts you need to make to get the extractor to fit. I've done it, it's doable, but is not for beginners and will be a much more expensive re-barrel job than on a typical modern rifle. You need both a mill and a lathe as well.
Hope that helps!
