38 Auto +P

Received a box with this end label:

Headstamp W-W SUPER (over) 38 AUTO +P:

Previous owner lathe turned down case rims to make 9mm Steyr out of them. Lot number is 36TA82 (28 Jan 1982), and product number X38ASHP later used on boxes labeled 38 SUPER +P. With 38 Auto coming out in 1902 and 38 Super in 1927, what’s the story with 38 Auto +P?

This may sound mistaken or confusing, but the .38 Auto +P is the same as the .38 Super +P, and both are the same as the .38 Super.

.38 Super vs. .38 Auto:

In 1974 Winchester-Western listed the .38 Super as the “38 Automatic Super-X” or “.38 Automatic Super Speed”, and the .38 Automatic was just that.
In 1975 and until 1979 these were designated “.38 Automatic Super-X + P” and “.38 Automatic” (Super Speed line dropped).
In 1980-81 the .38 Super was divided between “.38 Automatic Super-X” and “.38 Automatic Super-X +P”, but I think this was a mistake because it was ammended in 1982 and both loadings were again unified under the “.38 Automatic Super-X + P” designation. The .38 Automatic always remained the same.
In 1983 this mistake was again repeated (38 Automatic Super/38 Automatic Super +P vs. 38 Automatic).
In 1984 the final designation chosen for the .38 Super became “.38 Super Automatic +P”.

Was this box marked to indicate its contents were not intended to be fired in the older Colt “parallel ruler” pistols? Jack

Yes. There was a time when the only way to identify the Super Auto was by its nickeled case. The 38 Auto was plain brass.

Roundsworth: I was familiar with the older ID for the .38 Auto versus the Super, but I was curious if there was any reference in the context of this Plus P business to explain, in so many words, that you shouldn’t shoot these cartridges in your elderly 1900 Colt pistol. Jack

To complicate things further, there was also a time when the nickel was omitted from the .38 Super case, making these cartridges almost impossible to identify once taken out from the box.

As a side note, when the Argentine police received a small batch of Colt pistols chambered for this cartridge in 1934, at least some of the .38 Super ammunition supplied by Remington was headstamped REM-UMC 38 ACP, loaded with a 130 gr Mushroom bullet and had a plain brass case with a nickeled primer.

I have written several times, in various places, as have many others, that it is impossible to state whether a cartridge is .38 ACP or .38 SUPER with ammo that predates the .38 SUPER +P headstamp, without the original box label in hand. Ammo that is headstamped .38 SUPER will be that, unless it is a specialty load from someone like Dave Cumberland, formerly Old West Gun Room, that loaded some commercially-available .38 ACP ammunition for the older Colts, using the only brass he could get at the time, headstamped .38 Super +P. Even the pulling of bullets and weighing of powder charges offers no safe indication since many different powders, many not available to the average reloader, are used in factory-loaded cartridges.

The original separation by case material, plain brass for .38 ACP and nickeled brass for the .38 Super, went by the wayside in WWII when nickel was a critical material and eliminated from most commercial small-arms ammunition cases, and even before that in specific contracts for people who were not going to resell the ammunition and knew that despite a .38 ACP headstamp and a plain brass case, it was loaded to .38 Super velocities and pressures.
Of course, sometimes ammo such as this ends up being resold years later as surplus.

If you are contemplating shooting the older guns, don’t do it with any ammunition, regardless of headstamp, for which you do not have the original box label. Ofr course, the .38 Super, or most of them, works fine with .38 ACP ammunition - it simply gives “target pistol” performance rather than that of a full, self-defense load.