In the Single Shot Rifles sub-forum I posted about my early #2 RRB in .44 rimfire. I've put a centerfire block in it and am now in the reloading phase, so I thought it best to start a thread over here. The original discussion can be found here:
(You need to Login or Register to view media files and links) The centerfire version of this cartridge is very similar to the .44 S&W American, but a little longer. I determine the case length by seating a bullet in the breech. Then backing off .015". I ended up with a case length of .965". All other case dimensions are equivalent to .44 S&WA. To start out I purchased .44 S&WA heel bullets from BACO. I made cases from both 303 Savage and .41 Magnum. Both worked fine, but the .41 Mag rim is a bit small and will occasionally slip past the extractor.
This was my first time out with the 140+ year old rifle. My goal was to verify proper functionality, collect chronograph data and see if the bullets flew straight. I was successful on all accounts.
After a lot of research, I made up four loads to start, 10 rounds each.
Load #1 was 22.0gr of Swiss 1.5, lightly compressed, my home made black powder lube in the exposed lube groove. 303 Savage brass, WLR primer. This gave an average velocity of 1023fps.
Observations: This shot well, but I had one light hammer strike. Cases extracted easily.
Load #2 was 13.0 gr of Blackhorn 209, lightly compressed, my home made smokeless lube. 303 Savage brass, Fed 215 LR magnum primer. This gave an average velocity of 931fps.
Observations: This shot well, but I had one light hammer strike. I think the LR primers may be a little too hard for this rifle. Cases extracted a little harder.
Load #3 was 16.8gr of Reloader 7, filled to base of the bullet, my home made smokeless lube, .41 Magnum brass, CCI LP primers. This gave an average velocity of 1023fps.
Observations: This shot well, no misfires. Cases extracted easily. The avg. velocity was exactly the same as load #1 with Swiss 1.5. The agrees with what the late John Kort said. That a case full of RL-7 closely duplicates the original black powder loading velocity and pressures in pistol size case. I've had the same experience with .32-20 and .32-Ballard XL.
Load #4 was 5.0gr of Unique, my home made smokeless lube, .41 Magnum brass, CCI LP primers. This gave an average velocity of 807fps.
Observations: This shot very well, but case mouths were not sealing. Potentially the most accurate load.
Continued...