The Hodgdon website lists that with a steel-framed, 1858 Remington reproduction revolver:
Note: All measurements are by volume, not weight. For example, use a measure that holds 20 grains of FFFG
black powder to measure the listed 20 grains of Pyrodex 777.
.454 inch Hornady ball
One Ox-Yoke Wonder Wad
Hodgdon 777, FFFG-grade
20 grs., 536 feet per second
25 grs., 763 fps
Consider 25 grains as maximum for that Remington reproduction.
A maximum of 35 grains is listed for use with the Ruger Old Army .44 but that's is an extremely strong model of modern design.
A few years back, when 777 was new and difficult to find, I purchased a can of FFFG grade 777. At the range, I was under the assumption that it was like Pyrodex, designed to be used volume-for-volume with black powder.
So, I loaded a 40-grain equivalent into my Uberti-made reproduction of the 1858 Remington.
Wow!
I was clearly into the high pressure range, judging from the recoil and blast.
I fired the 6 rounds I'd loaded (rather foolishly, I admit, because I should have stopped after that first shot) and read the label.
Lesson learned.
So, I'd load no more than 25 grs. of 777 in that reproduction of a Remington.
To bring the ball closer to the rear of the barrel, so it doesn't have such a long trip down the chamber that may affect accuracy, use one or two
wool felt wads under the ball to take up space.
These wads should be lubricated with a natural lubricant such as olive oil, Crisco, bacon grease, beeswax, mutton tallow or a commercially made natural lube such as Bore Butter or CVA Grease Patch.
At the risk of sounding self-promoting, I've found that the lubricant now dubbed Gatofeo No. 1 Black Powder Lubricant is the best I've found.
The following recipe is very old; discovered by me in an old gun magazine. I refined the recipe by using specific ingredients. The old recipe was not so specific.
It is made by melting together 1 part canning paraffin, 1 part mutton tallow and 1/2 part beeswax. All measures are by weight, not volume.
Use exactly what is listed; substitution of ingredients with other substances will result in a lubricant with inferior properties.
Incidentally, Hodgdon lists a maximum of 25 grains of 777 with the Colt 1860 .44 too.
Somewhere in its long list of instructions and warnings I've seen the notation that Hodgdon 777
should not be used in revolvers with brass frames. Definitely heed that warning. For brass-framed revolvers, use black powder or Pyrodex.
Brass frames, being weaker than steel frames, should not be used maximum loads.