Originally posted by eric
If your rifle has index marks and a crown on the top of the barrel/receiver junction, it was probably reamed to accept the 11.7x56mm (not 51mm) cartridge when it was converted from rim fire to center fire. You can get a sample of the brass from Buffalo Arms and they will exchange/credit you for the shorter stuff if you haven't shot it yet (the 51mm brass will work - just loose a little accuracy).
I highly reccomend the Lee 405 HB bullet as it casts a little oversize and most of the Danish rifles slug around .462 - .465.
With that bullet cast 20-1 and unsized, I get great groups with the starting "trapdoor" 45-70 loads of H4198 for 400 grain cast bullets. I also use it (no wad) with a full case of FFg - almost as accurate - need to try a properly sized flat base bullet so I can use a wad and see.
One note is the Danish rifles have a slow twist and won't stabilize bullets much heavier/longer than 400-450 grains.
I use 45-70 dies and just barely resize the case mouth (decap seperately).
Mine was converted with a globe front and nice tang sight when I got it - fantastic shooting rifle.