Yeah, I can't find 35783 in Lyman's 1st (1958), 2nd (1974) or 3rd (1980) editions of its cast bullet handbooks.
Can't find it in the 1938 or 1957 Stoeger gun books, either.
I believe it's a misprint.
The 37583 is a short range bullet originally made for the .38-55 with very light charges of smokeless powder. Its design probably dates to the early 1900s.
Cast of pure, soft lead it may also be used as-is in the .36-caliber cap and ball revolver. Frankly, I've only seen 37583 bullets sold in pure lead, in black powder shops, for use in such revolvers.
Never seen it used in any rifles.
It's really not a good bullet for the .36 cap and ball, though. It lacks a reduced diameter heel on the base, making it difficult to get the bullet to sit up straight before ramming onto the black powder charge.
I bought and tried some 37583 in my Colt 2nd generation (circa 1981) 1851 Navy some years back.
It was too long to fit under the rammer, so I had to remove the cylinder, tap the bullet down a bit with a brass-faced mallet (never use any spark-producing metal around gunpowder!) and then put the cylinder back in the revolver to finish ramming.
Obviously, tapping a hand-held, greasy bullet into the chamber is not conducive to accuracy; it's almost impossible to tap it in straight.
It might work in the 1861 Colt Navy, which has a larger cutout in the frame for use with conical bullets.
But really, if you want to use conical bullets in the .36 (or the .44) order the Lee mould made specifically for these revolvers. It's designed with an undersized heel, to allow easy loading.
Enny-wayyyyyyy :roll:
If that mould is, indeed, the .37583 then it would be useful for a small game bullet --- when cast of wheelweights or harder alloy --- in the .38-55, .38-56 Winchester, .38-72 Winchester, .375 Winchester, .378 Weatherby, .375 Holland & Holland, .375 Dakota, .375 Canadian Magnum, .375 A-Square, etc.
Might be useful to carry a few of these loads in your hunting coat to knock off a rabbit or grouse you blunder across while hunting big game, to add to the pot back at camp.
When I say it would be useful when cast of wheelweight or harder alloys, this assumes that a small amount of a quick-burning smokeless powder would be used (Unique, Bullseye, W231, etc.) as the propellant.
If black powder is used, the bullet is best cast of very soft lead, with a black powder lubricant. Alox-based lubricants, or any petroleum-based bullet lubricants, when mixed with black powder create a hard, tarry fouling.
Besides, I can't forsee anyone wishing to use black powder in a .375 Magnum.