I picked up a danish rolling block that was redone back in 1889. I picked up Brass from Buffalo arms. the only reloading information is for the is for the 8mm danish krag which is 52 grains of imr 3031 on a 150 grain sierra bullet.  I backed off the powder charge to 48 grains.  I have not fired anything yet.  Am I barking up the wrong tree on powder charge. powder?  Page 397 9th edition of cartridges of the world. states it is the same power as the 8x58Rmm.  suggestion or advise.
sportslube

We have been using 235 grain Paul Jones spitzer bullets with 11.0 to 12.5 grains AA 9, H108 or WC820.

We breech seat the bullet and put a wad in the mouth of the case to get 1,400 to 1,500 fps.

Yes there is much concern about shooting the 8x58 R rolling blocks over 2,000 fps.

With the low receiver strength of most rolling blocks built for the 8x58R I would suggest 3031 may be of extreme pressure - since I have not seen any reliable data to use this in that cartridge or that receiver.

I used 47 grains of 3031 in a 45-70 and it kicked like a real nasty mule; I suspect 52 grains in a rolling block in 8x58 R would probably destroy the rifle.

Maybe Dutchman can post some safe hand loads for using jacketed bullets in 8x58 R rolling blocks.