[The following load is posted for the interest and curiosity of readers and is NOT intended as a recommendation for use in any other guns but my own. I CAN ASSUME NOT LIABILITY FOR ACCIDENTS OR INJURIES RESULTING FROM THE USE OF THIS DATA!Usual disclaimer.]
I have almost since starting CAS shooting used 8.0 grains of Hodgdon's UNIVERSAL...NOT CLAYS, although Hodgdon's has made IMHO a mistake in using the word "Clays" in conjunction with "Universal". Universal is very close to Unique in burning rate. Plain "Clays" is near Bullseye in burning rate. This load of 8.0 gr. is GREATER than the maximum shown by Hodgdon's for this powder, however, a hotter load is shown for 250 gr. bullets in .45 LC.
This load is used behind a 213.5 gr. hard-cast commercial bullet. I have fired about 3,000 rounds through a Navy Arms M1860 Military Henry replica (toggle-link action), with no noticable increase in headspace measurement. (Note that I seldom shoot this rifle nowadays, simply because it is quite heavy...NOT because I am retiring it from wear. This load runs around 1173-1210 ft/sec from the 24-inch barrel, depending on air temperature.
CAUTION: You CAN DOUBLE CHARGE A .44-40 case with UNIVERSAL, and the results would be serious, perhaps catastrophic! I use Winchester brass, and have gotten 20+ reloads from the brass, fired in both the Henry and M1892 Winchester clones.
This load produces 950 ft/sec from Old Model Ruger Vaqueros that have .425" throats and the bullets are .430" dia. I have not run pressure tests on this load due to lack of a gun that I can get a strain gage on for the Oehler M43 PBL, as my guns are stainless, and that is tough to get a strain gage to stick to.
I recommend dropping to 7.0 grains and working up using a chronograph.
Ride CAREFUL, Pard!