Hodgdon 777 is not to be used measure-for-measure against black powder, so you'll need to reduce it a bit.
As I recall, Hodgdon warns against using 777 in brass-framed guns. It's powerful stuff. Visit the Hodgdon site for recommendations on its use in cap and ball sixguns.
I have an Uberti-made Remington 1858 in .44 caliber and it's a fine gun. Very accurate. Mine has the fixed sights, but once I got them regulated to point of aim with my favorite load, I haven't needed adjustable sights.
I prefer using a greased, felt wad between the ball and powder. I soak the hard, wool felt wads in a home-brew lubricant I posted years ago and it has since been named after me as "Gatofeo No. 1 Lubricant"
The recipe is 1 part canning paraffin, 1 part mutton tallow and 1/2 part beeswax. All measurements are by weight, not volume. Substitution of any ingredient results in an inferior lube; stick to what is specified.
In my Uberti, I am unable to use a wad with 40 grs. of Goex FFFG and still have room to seat a .454 inch ball.
However, I tried 40 grains of Goex FFFG with a .457 inch ball. I pressed a wad of Gatofeo No. 1 Lube over the ball, for lubrication. Accuracy was poor and the bore heavily fouled.
I reduced the charge to 35 grs., which gave me room for the greased wad. Accuracy improved and the bore was much cleaner.
An accurate load in my Uberti is 30 grs. of Goex FFFG, and a greased felt wad seated firmly on the powder. Corn meal was added to the top of the chamber, then a .457 inch ball was seated.
Groups typically go 2" at 25 yards, from a benchrest, and the bore is very clean.
I pretty much use greased felt wads in all my cap and balls. And those wads are greased with the Gatofeo No. 1 Lube listed above.
I buy my felt by the sheet from DuroFelt of Little Rock, Arkansas.
Real, wool felt of the proper thickness and stiffness is difficult to find; so much of it is polyester and limp.
An old, felt hat is good but DuroFelt will sell you a large sheet of 1/8" thick real wool felt, from which you can punch thousands of wads, for less than $30.
That's about three or four packages of Wonder Wads, if you bought them.
I use a .45-caliber punch, purchased from Buffalo Arms.
There are hole punch kits out there, sold by Harbor Freight and such, but their 7/16th punch is too small (works well in the .44-40, though) and their 1/2 inch punch is too big (perfect for .50-caliber, though).
The .45-caliber punch cost me less than $20. It's very well made and hasn't dulled after hundreds of wads.
I guess I'm a grumpy ol' desert cat, set in my ways, but I've been shooting cap and ball revolvers since about 1970. I've learned a thing or two along the way, but I'm still learning.
I just recently purchased a Remington .36 with target adjustable sights. It was made in 1973, judging from the Italian proofmarks, and distributed by Navy Arms. I had it out a couple of weeks ago, but shivered the groups away.
When the weather warms, and the snow melts, I'll wring it out. It's a rare bird; the only .36 Remington I've ever seen with target adjustable sights. All those I've seen are .44 caliber.
Should be a fun, interesting critter to unleash.
