Hot 38 special vs. 357 magnum

[Questor]

I've read in various places that there isn't much difference between the 38 special +P loads and 357 magnums in short barreled revolvers. It never sounded right to me, but now I'm convinced.

I just happened along an article by Wiley Clapp in the February 1989 Guns and Ammo in which he had two revolvers, a 2.5" barrel and a 4" barrel. He used these revolvers to test fire a large variety of 38+P and 357 factory ammo loads. He compared apples to apples in the sense that he matched bullet weight and barrel length for each load compared. For example, in the 2.5" gun he fired 125 grain bullets and compared their velocities.

The results were conclusive. There is a large and significant difference between the 38 and the 357, with the 357 yielding velocities from 200 to over 400 fps faster.   This can be an increase of over 50% in muzzle velocity.

[Graybeard]

For sure I'm not a Wiley Clapp fan. I'm not sure he's actually held a gun in hand and fired it in years. Now he sure fires a lot from a Ranson Rest. Which is a reasonably scientific means of finding out wha the gun itself will do.

But yeah from personal experience there is a world of difference between normal .38 even +P loads and .357 Mag loads. Now old Elmer used to have some HOT .38 loads for use ONLY in guns strong enough for .357 Magnum and boy those weren't far behind the .357 Mag. I've shot them and they do work and are accurate and fast. But you sure don't wanna mix them up with any that might be shot in a .38 revolver cuz they might take it apart.

Even +P factory .38s are barely warmer than standard stuff. You're lucky to gain 100 fps with them. I think SAMMI spec is an extra 3000 psi on them versus doubling the pressure for the magnum round.

[Questor]

GB:
I don't follow Clapp's work that closely, but this looked like a good sensible test. I'd have done it the same way myself.  It was credible.

[dawei]

SNIP......................
Even +P factory .38s are barely warmer than standard stuff. You're lucky to gain 100 fps with them. I think SAMMI spec is an extra 3000 psi on them versus doubling the pressure for the magnum round.

IIRC 38 std press is 17,000; +P = 18,500; +P+ = 21,000 PSI

357 Mag = 35,000 PSI

[deerhunter]

As a reloader I found that I can beef up .38 specials almost at hot as .357 loads.   Now, all my guns are .357s, I do not own anything chamberes for just the .38 special.    I like the specials better because the eject better being shorter.   These loads are over .38+p in the manuals, but not as hot as Elmers.

One IMPORTANT note.   If you do some experimenting reloading hot .38+p loads, make damn sure you do not load the bullets deep into the case.   You want it bullet loaded out to or over the max cartridge length.   I only load cast bullets from my lee .358TLSWC mold, so its easy for me to load long.

I once loaded a batch of .357, with a 158 grain lead lee bullet over 12 grains of 2400.   This is a starting load in some manuals.   they fired like RipSnorters!  and would not extract without using a cleaning rod and tapping them out against the bench.

The problem I discovered was that I loaded them with the bullets loaded deeper than the min cartridge length specified in the manuals.  This develops HIGH pressure, even with a light powder load.  I was lucky that I was shooting my SW586 which is a strong gun.

Be really careful if you juice up those .38+P loads.......

but if you do it right, they are great.

[williamlayton]

The .38 super will come very close without the pressure.
The 9x23 will exceed but the pressure is in the small rifle range.
Blessings

[unspellable]

I am curently putting together the results of some experiments with cylinder gap.  Amongst the data I have standard 38 Special vs 357 Magnum from a single 357 Revolver with various barrel lengths on it.  The 357 has a substantial edge across the board.  What's more, the 38 Special cranks up more velocity from an eight inch barrel than it does from a ten inch barrel.