OK, I would like some opinions here.
I am loading 12.7x44R, a Swedish case from the 1800's. The rifles I am using are Rolling Blocks, made on the Remington patent by the Swedes, famed for their quality of work and materials. The Rolling Block action is stronger than, say, the Trapdoor Springfield, but possibly a little weaker than a Sharps.
There is *no* existing load data in any SAAMI source. No CIP data. Nothing. Not even BP.
The dies don't exist; we use 50/70 dies.
Brass doesn't exist, we use .348 Winchester brass for parent cases. Good strong, heavy brass. Trimming to 1.720" or so takes us into the stronger part of the cases, too.
These take standard .512" bullets for the most part.
Now, the volume of the case for the 12.7 is a little less than for the 45/70, but the bullets seat shallower; the actual powder volume is nearly identical.
The piston size of the 12.7 (.512") is more than the 45/70 (.458"), so pressures should be slightly less, all else being equal. .20578 in² vs. .16466 in².
Brass is at least as strong, arguably more so; the .348 Win was a fairly
high pressure case compared to the BP 45/70. It has heavier walls.
Both rounds were originally developed for a compressed load of Black
Powder.
The RB action is stronger than a Trapdoor Springfield.
It seems to me that any of the Trapdoor Springfield action level loads for a 45/70 should be eminently safe in the Rolling Block 12.7x44R as each of the variables seem to be tilted toward the Rolling Block for safety except for effective powder volume, which is the same.
Ideas? Opinions? Thoughts?
Larry
