Iím a sucker for the odd and unusual, and this one is indeed that. Itís a #1 Remington rolling block, made in the late 1860s. At that time there was a pile of surplus Civil War muskets available dirt cheap. In the post-war economy, Remington was looking for a way to build rifles at the lowest possible cost. So they acquired a bunch of old model 1861 and 1863 Springfield muskets, cut them up and mated all the parts to their large rolling block actions. This included the barrel, stocks and almost all the small parts.
Many had their barrels sleeved to .50 cal and chambered in either .50 Govt. or .50 CcarbineÖ.but not all. This one retains its original .58 caliber musket bore. Remington cut the breech end off of these barrels, threaded them to the rolling block action and then chambered them for several different .58 caliber metallic cartridges. After a lot of measuring, research and help of the Remington Society folks, weíve determined that this one is chambered in .58 Roberts. The chamber is a little longer than the .58 Carbine round, but shorter than the .58 Berdan.
Here is an original .58 Roberts cartridge:
So this is a new adventure in loading. I have some lathe turned cases from RMC that were made from a chamber cast. But they were too thick to hold a bullet anywhere near groove diameter (.594 - .595"). But I was able to ream them out with a $10 .5938" reamer off Ebay. I sized the cases first with a home made sizer, then reamed and fireformed. This allows up to a .596" bullet to be seated.
For the last 4 months I've been using a .590" diameter, 490gr minie' and 60gr of Olde Eynsford 2F with moderate success. They shoot well enough, but accuarcy has only been 4" - 5" at 50 yards. Here is a loaded .58 Roberts round with a .56-50 Spencer to its left for comparison, an empty case (before reaming) and a minie' to its right.
Recently I obatained a few sample bullets from a fellow who had a custom adjustable mold made for his .58 Berdan roller. The mold is adjustable for length, throwing both a 400gr and a 560gr bullet. He sent me 10 of each. Their OD is .596", .006" larger than the minies I had been using and a much better fit to the barrel.
I was able to load the short bullet with 60gr of Olde E 2F. But with the long bullet I could only get in 47gr. With the slow 1-72 twist, I expect the short bullet will shoot better. But I won't know until I get to the range. But I have high hopes!
I really like the short version of this bullet and I think it will shoot pretty well. I've looked at Accurate Molds web site and they have several designs that look promising. But if this short bullet works well, I may send him one to copy for a mold. I really think the long bullet is too much for this slow twist and powder capacity, but I'll give them a try.
If any of you boys shoot a big .58, I'd like to hear your experiences. I know there are a number of folks who shoot Snider conversions of similar bore size. Comments and discussion welcome.