Okay, getting back to the original question of .44-40 vs. .45 Long Colt.
I started reloading for the .45 LC back in 1973, on a Lee Loader for my then-new Ruger Blackhawk with 7-1/2" barrel.
I used the Lyman 454424 lead bullet, cast 1 part tin to 10 parts lead, lubricated with an alox lubricant. This was usually over 8.5 grains of Unique, though I dallied with 2400 from time to time to create very heavy handloads.
JD45, I must take issue or at least clarify your statement, "A straight-wall case is easier to work with than one with even a slight "bottleneck" shape, as the .44-40 has. You won't need to lube it before resizing as you will with the other, to insure that it won't get stuck in the resizing die."
You probably meant to say that when using carbide dies with straight walled cases, you don't need to lubricate the case. At least, I hope you meant to say that.
God help the reloader who forgets to lubricate a .45 LC case and runs it into a standard die. I've done it, absentmindedly, and it's a bugger getting that fat case extracted after the shellholder's torn off the rim.
Incidentally, the .45 LC cases of yore had very small rims. With the older cases, usually of balloon head construction, you run the risk of tearing a rim off without ample lubrication.
Some older cases have such a smidgen of a rim that to prevent damage it might be wise to size these cases in a Lee Loader, where the case is tapped into the die and then tapped out from the other end with a steel rod.
I still use the ink stamp pad method for some cases. The stamp pad is dampened with case lubricant and cases rolled across the surface. Of course, you must buy an uninked stamp pad for this purpose.
But I digress ...
For a newcomer, I would suggest the .45 Long Colt as the better of the two. You will have a wider selection of bullets from which to choose, all the way from the tiny 185 gr. jacketed or lead semiwadcutter used for target work in the .45 Auto (but works great for targets and plinking in the .45 LC too) to the massive 300 grains-plus lead bullets.
If I could pick but one bullet, it would be my Lyman 454424 mould. This casts a plain-based, semi-wadcutter, of Keith design, weighing about 255 grains when 1:10 alloy is used.
This bullet is accurate, easy to cast and load into a case (no troublesome gas check), and delivers the goods on target, beast and man (haven't shot the latter two with it but others have and report excellent results).
My Lyman 454424 mould is no more. Some years ago, Lyman slightly reduced the diameter of the mould and redubbed it the 452424. No matter, most .45 Long Colts of today have bores of .451 to .452 inch.
I size my old 454424 bullets to 452 inch. With 1:10 alloy they drop from the mould at about .455 diameter.
I also reload the .44-40, but in a reproduction 1873 Winchester rifle. It too is a great round but not nearly as versatile. No matter, I only shoot 200 gr. lead bullets in it, sized to .429 inch (the .44-40 rifles of today tend to have larger bores than the originals, hence the slightly larger bullet for best accuracy).
I like both rounds, but the .45 is easier to reload and has a greater variety of bullet weights and styles, should you wish to take up hunting or target shooting with it down the road.
As for the .32-20, this is a grand old round but my understanding is that it can be equalled with the .32 Magnum. The .32-20 is also a necked round and requires lubrication of the case before sizing.
I have no experience with either, but from what I've read the .32 Magnum will do anything the .32-20 will do. I don't know how the cost of ammunition compares.
A strong word of caution: In the past 10 years or so, I've witnessed a proliferation of reloaders posting loads that are well beyond the maximum charges suggested by the reloading books.
These reloaders --- without benefit of a modern ballistics laboratory --- claim their loads are perfectly safe.
The trouble is, each gun is an individual. What one gun may take may strain and even blow another gun.
Always check someone's load against a modern, creditable reloading book. I suggest you buy the Lyman No. 48 reloading book as a good all-around reference. Other excellent books are made by Speer, Hornady, Sierra, etc.
When the Ruger Blackhawk in .45 LC was brought out in the early 1970s, ignorant reloaders immediately started trying to make it rival the .44 Magnum.
Why they didn't buy a .44 Magnum in the first place puzzles me.
Remember, as you increase pressure with your loads (whatever make your gun is) you accelerate recoil, muzzle blast and --- most importantly --- wear and strain on the gun.
For most purposes, there is little need to push a 250 - 260 grain bullet in the .45 Long Colt beyond 1,000 feet per second.
If you want to experience the blast and recoil of a Magnum, then buy a .44 Magnum or .454 Casull.
I wish people would stop trying to magnumize the .45 Long Colt. It is sufficiently powerful with reasonable loads to get the job done.