Let's start with the 1851 Colt.  It was a .36 caliber pistol because the convention was to use the bore size of .36".  The groove was about .375" and the cylinder bore diameter was .380" (this is for originals not modern copies). So far so good?  Now, when cartridge conversions came about, the rear of the cylinder was milled off and than was it.  The cartridges used heeled bullets so the case diameter, the bullet, and the cylinder bore were all .38". 

The first cartridge was the .38 Colt for use in 1851 and 1861 conversions.  The name was based on the diameter of the bullet.  It was later renamed the .38 Short Colt. 

The next cartridge in the series was the .38 Long from UMC.  It was a .38" heeled bullet cartridge with the case lengthened to allow more powder capacity and was developed by UMC for Colt's Newline revolvers and centerfire conversions of the 1851 and 1861 Colt revolvers requested by the US Navy.  Because it was developed for this contract was also known as the .38 Navy.

The came the .38 Long Colt. It was used in the Colt M1892 revolver.  This black powder cartridge was internally lubed.  As such the diameter of the bullet was now the same as the inside diameter of the case and not the outside.  Its bullet diameter was now .357".  The case of the .38LC was 0.14" longer than the .38L to allow the case to cover the lube grooves and still have the same overall length and powder capacity.  This was also known as the .38 Army.

After the .38 Long Colt came the S&W .38 Special.  The case was again lengthened to 1.15" and reduced in diameter to .379".  It was transitional in that it was introduced just before smokeless became common and was loaded with smokeless soon after it introduction.

Next came the Remington .357 Magnum.  The case was lengthened again and was a true smokeless cartridge.

Slim, Go here for the information
https://www.guns.com/news/2022/10/07/gun-buyers-aged-18-20-now-set-for-enhanced-background-check-process

I found that one also. I've been ranting since I found it. These people need to be fired and constitutionalists need to be elected in their places.  I said other things but won't put them in writing especially on the internet.
https://www.guns.com/news/2022/06/24/meanwhile-in-the-senate-bipartisan-anti-gun-bill-rushed-to-house

Slim

Slim, Go here for the information
https://www.guns.com/news/2022/10/07/gun-buyers-aged-18-20-now-set-for-enhanced-background-check-process

Fascinating, stunned, and thanks:

Dusty, I will be happy to share all of what I have learned from Larry Romano and other owners of his Spencer's. 

For now, I believe he made approx. 66 Spencer Model 1860s, with Larry telling me rifles accounted for about 25 percent. 

There is a lot more to this topic and I can help.  My use of "help" is important.  May I suggest you QUICKLY PM me here with your phone contact information.
Very respectfully,
Kevin Tinny

Coffinmaker Checks.  Are the birds to be roasted or fried