No being expert on 38 Super is 38Super + P a heavier load than 38Super? I ask this because it has been stated this is only a designation to differ it from 38acp. I know what 38acp is and what guns it was intended for. I’m not sure if I’ve ever saw 38Super+P ammo.

I have two Colt .38 Supers, another on order, and about 400 rounds of ammunition from various makers. All the boxes are marked .38 Super Auto +P. I believe you are correct that the +P designation is intended discourage use in the older and weaker .38 ACP firearms. I have never seen .38 Super ammunition that was not marked +P.

No, in fact the +P designation was only added because .38 Super is just a hotter loaded version of the obsolete .38 ACP cartridge, (not to be confused with .380 ACP, which ultimately replaced .38 ACP) and will chamber in old blowback operated .38 ACP pistols which cannot withstand the higher pressures/bolt thrust of .38 Super.
Well apparently the "Super" designation on its own wasn't enough to tip off certain folks that it's loaded hotter than .38 ACP, so SAAMI decided to designate the .38 Super cartridge as +P by default.

That being said, nowadays there are lighter .38 Super loads which are roughly equal to 9mm Luger, (full-power loads are on par with .357 SIG) and those tend to be labeled without the +P designation in order to tip the buyer off that they're lighter than full power loads, yet not so light as to be labeled .38 ACP, which is closer to .38 Special in terms of power.

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Shooting Comfort is bilateral.

The +P designation was invented for 38 Super

All 38 SUPER is designated +P

It was in the hopes that folks owning firearms chambered if the lower pressure 38ACP would not use it in their auto loaders.

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"Acta non verba"

You are correct. SAAMI introduced the +P designation in '74 to differentiate 38 Super from the lower pressure 38 ACP. Super 38 pressures were not increased. It was just a labeling change in the interest of safety.

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NRA Life, COTEP 640

It seems odd a manufacturer would label an ammo box with a designation that doesn't technically existing in the SAAMI specs list, "38 Super".

Doing a search I was only able to find one ammo box's end view which was labelled with only "38 Super", Fiocchi, but end views are hard to find though.

Since standard 9x19 max pressure is 35K psi & 9x19 (+P) is 38.5K psi, I don't know how someone could gain anything meaningful from that labelling since 38 Super +P pressure is 36.5K psi, SAAMI pressures. (38 Automatic pressure is only 26.5k psi.)

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Waiting for the break of day

The .38 Super doesn't really exist...as stated above it is really only .38 ACP +P. When the 1911 was first chambered in .38 ACP it was the gun that was called the Super .38 not the ammo. As the velocity was increased from 1080 fps to 1300 fps by the early 1930s it was still only called .38 ACP. From what I have read the boxes were not even labeled .38 Super till the 1950s.

But not all factory .38 Super ammo is the same... Many of the rounds are nothing more than .38 ACP and others are easily +P+... The chamber pressure of a Federal 115 that only has a listed velocity or 1130 fps can't be near the same pressure as a CorBon 115 that is running 1450 fps but yet both are listed as +P but they are all safe in "modern" .38 Super chambered firearms...

It would be nice if SAAMI established three levels of pressure for the .38 Super like they do the 9mm...but then again maybe we Super Shooters are better off without SAAMIs "wisdom"....

Bob

Yes, I stumbled on a very nice old Super in my quest for a Colt Gold Cup, and I'm glad I did... I once purchased some "Corbon 38 Super +", but after a little research sent those two boxes of dynamite down the road...

I had lost my spare Super 38 magazines in my recent move to my Mother and Father in Laws house that we remodeled.... I was in complete distress until I found them in an Abu Garcia fishing reel box in my tool box, LOL.

I would add that two of those magazines came from our good friend David Carrol, back when he had those lovely add's in the "Gun List"... I would drool each month waiting for the gun list, and saving David's ad for last.

According to the gurus at my LGS, all 38 Super is +P whether it's marked on the box or not.

It doesn’t have to be confusing. The first Colts were 38acps. The hotloading came out and it was named 38Super to keep it from being used in the early pistols. End of Story anything else just adds to the confusion for those who don’t know the history of 38acp-38Super.

"Yes, I stumbled on a very nice old Super in my quest for a Colt Gold Cup, and I'm glad I did... I once purchased some "Corbon 38 Super +", but after a little research sent those two boxes of dynamite down the road..."

Billy...if the Super was made before 1990 and had the original headspace on the case rim barrel, it was not a bad idea to have send them down the road... That said I have shot probably 20 boxes of CorBon ammo though my guns without incident...but all have the headspace on the case mouth type chambers. Their 115s and PowR'Ball were my carry ammo up until changing over to the Underwood Xtreme Defender...

Bob

Ironic perhaps, the warmest factory 38 Super ball ammo I've encountered, GECO, is not marked +P. The GECO 124 grain ball averages ~1350 FPS in my 5" guns. I've also used Winchester, Remington, Federal, CorBon,Underwood,etc. 38 Super. I just don't use it in my old 1914 Colt 38 ACP Pocket Hammer.

Then just to confuse things further, there's that darn ."38 Colt Automatic ammo"

Attached Images

Old Colt and ammo (25) - Copy - Copy.JPG (97.7 KB, 16 views)

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NRA Life, COTEP 640

Rock185s explanation of 38Super +p is best and most to the point given.
+P designation added in 1974 to distinguish it from 38acp.

+P was not always on 38Super labels and I guess not on all now. The 380 has nothing to do with 38acp. It was never a replacement for 38acp.