.38 and .357: what's the real story?

EdGCNM

EdGCNM

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This has always bugged me, but since I don't own one I guess it never got to the top of the pile. In talking to a fellow shooter who does own one, though, it brought it to mind.

.38 special isn't .38 calibre at all, it's .357 calibre -- .36 if we want to round it off. So why the heck is it called .38??? This is one of those stupid firearms things that just makes no sense (yeah, I know there are lots of them).

Does anybody know the history behind this oddity? I did some Googling and the best I could come up with is that it actually refers to the diameter of the hole for the cartridge in the cylinder, not the bullet. That sounds like it would be about the right measurement. Something to do with cap and ball in the cylinder during the conversion to metallic cartridges? That didn't sound so sensible to me, but you never know. I've also heard that the .38 refers to the diameter from groove-to-groove depth rather than land to groove, but I don't know if that would account for such a big difference.

What's the truth?
 
.36s were actually .38s & vice versa.

When we went from cap & ball to cartridge they basically used bullets similar in design to the .22lr. This is refered to as an outside lubricated bullet.

There was a short case diameter stem which was crimped into the case mouth, the main body of the bullet was groove diameter & outside case diameter. There was a grease/wax lube coating on the outside of the bullet.

To accomodate this bullet the chambers were bored staight through.

This cartridge was debuted by Colt about 1870 (.38 Short/Long Colt). The Long version became the US service cartridge in 1889, adopted in the Colt M.1889 revolver (the first production side opening cylinder revolver!).

In 1899 S&W redesigned the .38 LC cartridge (the case stayed the same) along the lines of the .44Russian (an early inside lubricated cartridge) & reduced the bore diameter of their new Military & Police (today known as the M.10) to suit it. By about 1905, most of the manufacturers (including Colt) had altered their guns to suit the new .38 S&W Special cartridge.

There was now a noticable "step" where the chamber changes to bore diameter.

I really hope this answers your questions

Regards
D
 
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I think I get it. The original cartridge was a heeled round, like the .22, where the bullet tapers to a heel at the back to fit into the case, making the bullet diameter and the outside case diameter the same, and the lube is applied to the exposed part of the bullet. It was a true .38 calibre round. Later, when the same cartridge case was adopted to use the more modern bullet design with inside lube, the bullet/bore calibre had to be reduced to .357 (in effect, the inner diameter of the case). It continued to be called a .38 even though that was no longer the actual calibre. Right?

That's great -- thanks for answering a question that's bugged me for a long time!
 
EdGCNM said:
I think I get it. The original cartridge was a heeled round, like the .22, where the bullet tapers to a heel at the back to fit into the case, making the bullet diameter and the outside case diameter the same, and the lube is applied to the exposed part of the bullet. It was a true .38 calibre round. Later, when the same cartridge case was adopted to use the more modern bullet design with inside lube, the bullet/bore calibre had to be reduced to .357 (in effect, the inner diameter of the case). It continued to be called a .38 even though that was no longer the actual calibre. Right?

That's great -- thanks for answering a question that's bugged me for a long time!
Click to expand...

Exactly

Regards
D
 
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