The .36 cal cap and ball goes way back, in a rifle it was considered a squirrel gun.
As the photo shows, the ".36 round ball" is actually .375" diameter.
The earliest of the smokeless cartriges in .38 was the .38 S&W from 1877. These dimensions have been carried on up to the .357 Magnum. Only difference being overall length.
The .38 S&W operates at cup pressures of 14,900 or less.
The .38 Special was introduced in 1902, again, just a bit longer casing.
Operating pressure of 18,900 max.
The .38 Special +P has the same dimensions as the non +P yet operates at 22,400 cup.
The +P is intended for use in Medium and Large frame revolvers only, even then extreme care should be used to watch for signs of excessive pressure. (just don't use them if your gun is not marked as suitable for .38 special+P)
1935 saw the introduction of the (blockbuster) .357 Magnum. The FBI Wanted a handgun cartrige to stop John Dillinger by cracking the engine block of his getaway car thus causing overheating and siezure. (Dick Tracy immortalized the "MAGNUM" in the comic strip.)
The photo (I hope) shows the length difference in .38 special and .357mag.
It is unwise to fire even a mildly loaded .357 cartrige in a .38 firearm as the chamber is not long enough and the casing will become lodged, making extraction difficult at best. (ask me how I know).

11 Comments
Vaquero
TBH wants to go out for supper.
Yep, that's what I want too! LOL!
elgoo
How do you know?
HKBauer
Know what?
Vaquero
If you will be more specific with your question, I'll be glad to answer.
elgoo
Ask me how I know are the last 5 words of the post. haha. about the light .357 load in a .38
CharlesW
You need to repair that gun.
A 38spl cylinder will not hold a 357
It's too long for it.
Something here doesn't add up
and I just tried to load my 38 with
357s. They just don't fit
I knew thew wouldn't but tried it anyway.
You might have some cut down brass
that says 357 loaded for 38.
I've done a lot of that when the cases
get wore and start to crack
Vaquero
OK, sorry about that.
What I referred to was a hloow base wadcutter, seated completely in the casing of a .357 mag.
This leaves only the very top, or front, of the bullet visible. My bud had an early taurus revolver in .38 sp with straight bore chambers.The cartriges would just fit and the cylinder would rotate.
After firing, the cases were stuck in the cylinder and we had to drive them out.
As CW and Greg have mentioned, 99% of the time a .357 round will not fit in a .38 sp.
HampsterW
Evil things can come from there...( I have come to appreciate mine )....Catch ya' later Vaq!
greg az
More model 10's around (least K frames, or copies) than any other single weapon, and a lot of this came from it being the universal LE sidearm for a good 75 years.. Some agencies still use them, and read the other day that some seal teams use the model 65 (thats the stainless non adjustable Smith 357) for action that requires long term ocean carry.. Don't know that this means anything as im sure they use everything made including Hamps gamo..
I do know that J&G has some great buys on the 3" stainless K, not sure if its 65 or 66 (adj site) these are DA only de spured ex FBI issued.. Point here is a bunch out that are still in service, and that round.. between the 9 (355) and 38 (357) is used in everything from 9 kurtz, baynard, 38 special, 38 (the auto round and one hot stepper) super, 38/200, 38/40 you get the picture..
All of these are interchangable, and if you can't find a bullet you want in 38/9 your way to picky, you have so many options you can tailor a round to fit what ever your needs are.. The ones Pard loads for me, his pattented "padre plinkers" are 125 gr that don't quite hit 800 fps, so sorta like shooting a hot 22 in a light weight piece.. My little freedom 22 has more kick, (bout the same stoping power to)
Actually these have still got enough pow in them at 800 to do the trick, and a great all around bullet..
greg az
least ive never been able to.. you know right away when you drop the rond in, the only problem ive had in terms of seating was the blackhawk in 30 carbine.. that round is real sensitive in the revolver as far as seating, and sometimes if it wasn't trimed and on the money the cyl would't rotate.. The only time i've ever had a function issue on a rev.. and of course NOT what the bullet was designed to fire out of.. Loud, and fun, but sorta wierd.. my venture into silloete shooting.. Don't know why i never did it.. Maybe the recoil.. Had a 6" 686 that was more accurate at long distance..
CharlesW
Have you ever seen a Johnson LMG ? (light machine gun)
It was issued up until 1961 to Special
Forces Units.
Mag fed from left side and recoil barrel.
It was the 4runner to the AR15