9mm Super Cooper?

[SharpsDressedMan]

Anyone ever done the Jeff Cooper 9mm Super Cooper (cut down .223 case) on a 1911? With the shortage of 9x23 Win brass and ammo, but a lingering desire to have a high performance 9mm in a 1911 (say a 125gr bullet @ 1600-1700fps), the Cooper looks pretty good. Anyone ever done up a gun, or shooting cut down .223 in a 9x23 barrel, etc?

 

[cheygriz]

Take a look at the 9X25 Dillon.

A lot easier to form the brass.

 

[Mastiff]

I bought 2500 once fired 223 cases for $115 delivered (less than 2 cents a case). I trim it down and swage the primer pocket crimps. I mainly shoot it out of my Tokarevs. All it took was reaming out a spare 9mm barrel. I also shoot it out of my Star Super A. The pistol is chambered for the 9mm Largo round, which is a 9x23 round. I only modified it by using a stronger recoil spring and a shock buff. The guys at the Spanish military handgun forum are sure I'm going to blow up the pistol, so if you try it it is at your own risk. They don't even want you to fire 38 Super in the pistol, which I think is really bogus. The Star Super A looks a lot like a 1911 minus the grip safety.
I'm still thinking about converting my 1911 to 9x23 Winchester, but since I have a lot of pistols to shoot the round through already (6 pistols at this point), it isn't a high priority.

 

[SharpsDressedMan]

I checked a lot of internet references on the 9x25, and it still appears that the 9mm Super Cooper outperforms the 9x25 Dillon. Not sure why; as stated, the 9x25 has more case capacity. The 9mm SC seems to have the same strength and operate at the same pressures as the 9x23 Win, so the higher pressure margin may be the reason. In any case, being able to use cheap .223 cases when 9x23 Win is almost unobtainable would be my reason for going that direction. One or two thousand cases cut down and prepped would last me along time, especially when I'm looking at this as a conversion for my .38 Super to be used for long range plinking and hunting of medium and small game.

 

[LeonCarr]

The old 9mm Winchester Magnum (Supposedly chambered in the Wildey Pistol, but I dunno if any ever where), and the 9mm Super Cooper were/are bascially the same round.

Doesn't Starline offer brass for the 9x23? Could .223s be trimmed down to 23mm and inside neck reamed for 9mm bullets?

Just my .02,
LeonCarr

 

[Mastiff]

Could .223s be trimmed down to 23mm and inside neck reamed for 9mm bullets?

That is what I'm doing. I first got the idea from Dane Burns site, see below. I'm retired, so I have a lot more time available than $$. Less than 2 cents a case sounds like a good deal to me. Starline has stopped making the brass, and the price I've found for Winchester brass is 38 cents a case.

From the site:
Cooper had spent some time in '70/'71 in El Salvador. One of his students Mario Sol, hot-rodded 38 super hand loads and declared it a suitable trail and self defense load. It is worthy to note that Cooper was in El Salvador to teach self defense. The use of a hand gun against humans was and is his forte. Cooper was impressed with the man and his hot rod 38 super. Members of the Southwest Pistol League took over the project and pushed the 38 super case with a 130 grain bullet to 1350 fps. (Corbon commercially loads a 124gr @ 1350 fps now) That was a stout 38 Super load, but Cooper and others wanted a "real" 357 Magnum! John Adams was getting 1750 fps from a 90 grain bullet and 1600 fps from a 124grain bullet before typical 38 super cases blew. This was from an unsupported 6.5" Barsto barrel. It was also with powders from 1970!

Besides the other well known pistoleros involved here, Major George Nonte was playing the same game. His addition was chopped .223 brass to replace the 38 super brass and to head space the 38 super on the case mouth instead of the semi rim.

Wowie, zowie! The first 9x23! In a case designed to take rifle pressures, 52,000 psi to be exact. Winchester 9x23 is designed to take 48,000 CUP. And in Winchester's own words, "The strongest case ever built for a center fire cartridge". Amazing how much the 223 case and a 9x23 Win case look alike when dissected.

With the 223 brass Cooper was able to safely get a 124gr bullet to 1700 fps and a 90 grain bullet up to 2000 fps. Even Cooper was impressed with those numbers, tiny bullets and all. His comment, "I intend to carry it a lot while boon docking. While it was never intended to be a fight stopper, one would be well advised to stand out of its way, (it) should prove to be a reliable fight stopper if ever called upon." "It will shoot as flat as any man alive can hold."
http://www.burnscustom.com/showarticle.php3?article=9x23/9x23WhereAreWe.php3