The new Hodgdon 2006 handbook(I just picked up)also has data for the .50x3-1/4" with Lyman 512gr. FN cast at almost 2,100fps and under 28,000CUP as well as the Lyman #515141 in 425gr. (harder lead) running almost 2,300fps and at 28,100CUP.
: In this case, PSI (used by AArms) and CUP used by Hodgdon appear almost equal, # to #. The .45/70 also seems to follow this trend. It is possible, that with pressures higher or lower, the numbers don't co-relate, such as most all other ctgs. show at any pressure level.
: Incidently, .470 Nitro data runs 500gr. at 2,159fps, only 60fps faster than the .50's top load listed here, but the .470 data is 25fps behind the top-end AA load for a 550gr., .50 cal. bullet.
: This is indeed a VERY powerful ctg. when loaded with smokless powder, even in a Sharps or Remington Rolling Block of modern manufacture.
: Your Martini should even increase upon these loads, if your shoulder is up to it. I know for a fact, that shooting well over 100gr. of smokeless behind a .50 calibre bullet, kicks pretty hard. It should equal with ease, the factory .500 nitro ballistics of a 570gr. at 2,150fps and do it with less than 35,000PSI or CUP.
: Hodgdon used Federal 210M primers, while AA used Federal 215 primers. Even with the hottest primers, we had unburnt powder left in the bore. This is due to the slow powders being used to fill the case, aren't good burners at such low pressures. They do give good accuracy and shot to shot consistancy, though.
: Keep me posted on this rifle, Colorado. I am interested in how the big Martini stacks up.- or is it a Double Rifle? I just took for granted it was a single Martini, for some reason.