Good evening, I have a Danish built rolling block in 11.7x56r. It is a lot like a 45-70 and mine has in fact had a reamer of same put into it by an importer. The bore is gorgeous and the rifling is 5 lands and  .018" deep grooves. When 45-70 cases are fired they are swollen bout .010" at the base when they don't split. it has a slower twist and will not stabilize bullets over 500g. I have about 40 cases formed from 348 win. Half are trimmed to 51mm the others are 56mm. They came with the gun. When I short start a bullet in a case and push it into the chamber until the bullet engages the rifling it looks like a 45-90 case will chamber. These things were throated long when the Danes went to jacketed bullets.  Last weekend I dug around and found a few 400g Lyman bullets and some Lee improved mini-ball bullets for the .45 muzzle loader. I loaded the mini's over 55g of goex cartridge and they went bang and into a 6" circle at 50 yards. I did all of the things that we do to make them shoot straight as in, card, compresion, settling the charge etc. I'm pretty sure it's the under sized hollow based bullet that did me in. Later I loaded the 400's over 13g of unique and got much better results. These bullets measured .459" and were fairly hard. They hit to point of aim at 50 yards and I was able to hit my 150 yard gong without moving the rear sight. I did raise the front blade in the rear sight notch to be level with it's top. After going on line and digging as much as I could stand I found that a lot of guys like these rifles and they have good luck shooting the Lee 405g hollow-based bullet so I ordered that mold rather than a custom one. I had one some years ago and it irritated me so badly that I let it become beer cans. This one casts very well as long as I am mindful while I close the mold. The little hollow base forming pin loves to grab the mold blocks and not close when it gets warm. I spread a tiny bit of never-seize around the pins base and it helped a bit. These bullets measured .459 at the top driving band and .461" at it's bottom. I lubed these with SPG black powder cartridge at .459" because that is what I have and filled the hollow base with lube. These bullets were loaded over 65g of Olde E compressed with no card into the 56mm cases. The 51mm cases were loaded with 55g and the bullets were seated to the same depth as the longer cases. I made 6 of each and went out the back door. I rested my elbows on my bench and fired then blew into the chamber without my smoke snorkel blow tube. They shot great. The longer ones looked as if they would have made an inch if I'd used bags. The shorter cases made 3" shooting wit the same style. I have a picture of the rig on my phone. I'll post it later when I figure out how. I did put it up on a cast bullet facebook group and got had a very nice slow typing conversation with a gentleman from Denmark who sent me links from Danish arms museums regarding the rifle and it's ammunition. I had FUN today!