I've had this one since 1983. It is a 4 3/4-inch .38 WCF (.38-40) that was originally shipped from Colt to Hibbard, Spencer, Bartlett & Co. in Chicago, Illinois on April 24, 1905 as one out of a shipment of 15 revolvers.
It still sees regular use, both in the field and on the range despite the horrified protestations of some modern day collectors. That is what it was made to do.
I used to use it for some experimental handloading up into the "Elmer Keith" range of load intensity just to see what sort of capabilities the .38-40 possesses. While I never "went out on a limb" beyond published data, some loads were worked up from from older loading manuals that were truly potent ... as in the 10mm Auto range of performance. These loads would handily beat out any .40 S&W concoction. Somewhat misnamed by Winchester, the originator of the round, the .38 WCF or .38-40 as it was later called, has a true .40 bore. Any common bullet useful in the .40 S&W or 10mm may be fired from a .38-40.
Here's some fun data from chronograph sessions of bygone days.
Factory load: Winchester 180 grain jacketed soft point
928 fps muzzle velocity 347 ft./lbs muzzle energy
My standard field load using a mild charge of Unique and a 172 grain cast lead bullet
829 fps 262 ft./lbs
Hornady 170 grain JHP (component bullet intended for use in .40 S&W)
IMR 4227 993 fps muzzle velocity 371 ft./lbs muzzle energy
Unique 1107 fps 462 ft./lbs
172 grain cast lead semi-wadcutter (Lyman No. 40143)
40 grains FFFg black powder 916 fps 321 ft/lbs
IMR 4227 1053 fps 425 ft./lbs
Unique 1211 fps 552 ft./lbs
These days it only sees use with the cast lead 172 grain bullet and mild charges of Unique unless some black powder loads are made up for fun, just to let someone shoot the .38-40 with all the smoke and thunder of its 19th century glory.
It shoots to point of aim at 15 yards with both the black powder load or the mild Unique load and groups pretty well.
My wife poked this hole in the cactus using the .38-40 Colt from about 12 yards. The revolver sees a lot of this kind of low-key plinking entertainment. We have a lot of shot-up cactus on our place.