9mm Largo

[boomer1911a1]

I am well-familiarized with the specs and ballistics of most of the 9mm/.38 family: .380 Auto, 9x18mm, 9mm Luger (aka 9mm NATO, 9mm Parabellum, 9x19mm, etc) .38 Auto, .38 Super, 9x21mm, 9x23mm, .356 TSW, .357 SIG...
Where does 9mm Largo fall in the heirarchy? I've seen it in the Shotgun News chambered in Astras and Llamas, which leads me to believe it's a Spanish cartridge (a regular Sherlock Holmes, I know) but what are the case dimensions? Can the guns be rechambered for .38 Super?

Any info will be appreciated, but no links, please. My work firewall shuns "weapons" sites...

Thanks!

 

[boomer1911a1]

Helps to take ones own advice...

I often tell people to do a search before posting a question. I just did and found out quite a bit. Sorry! Feel free to delete!

 

[ButchG17]

The 9mm Largo is a 9x23mm, but it's standard loading is very nearly the same as a 9x19, a 123 grain bullet at something under 1200 fps.



Butch

 

[Starter52]

Butch is dead-on. The 9x23 Largo and the common 9x19 Luger are just about identical.

I can't believe how many otherwise knowledgeable writers insist that the 9mm Largo is "a 9mm magnum". Rubbish.

 

[herohog]

Most don't even know there is a REAL 9mm Magnum... the 9x29 9mm Winchester Magnum! Even it isn't QUITE as powerful as the 9x23 Winchester, NOT 9x23 Largo! NEVER fire a 9x23 Winchester in a 9mm Largo! BAD JuJu!

 

[Mastiff]

From the people selling the Star Modelo Super A in 9x23 Largo, Sarco Inc:

Ballistic Comparison
38 Super: Muzzle Vel.= 1200 pps / Muzzle Energy = 368 ft. lbs.
9mm Largo (9x23mm): Muzzle Vel.= 1280 pps / Muzzle Energy = 420 ft. lbs.

I have no worries at all in firing a 9x23 Winchester in my Star Modelo Super A. The 9x23 is rated at 50,000 CUP. The Super A's have been tested at 60 and 70,000 CUP with no problems. People have been firing 38 Super in these guns for years. The pistol is built like a tank. Just my opinion, YMMV, I have fired the 9x23 Winchester in my Star Super A I just bought from Sarco, no blow-ups, no problems.
WARNING! DO NOT attempt to fire these rounds in the older handguns chambered for the 9x23 Largo, most of the early pistols won't handle it.
I also have converted a Tokarev to fire the 9x23 Winchester. No problems there either.

I know I'm going to get dumped on, but there you are.

 

[Mad Magyar]

The 9x23 Largo and the common 9x19 Luger are just about identical.

They are not even close to identical. The Largo is more powerful in velocity & energy....Check any ammo info....

Edit: The following posts indicate that I am incorrect. I stand corrected.

 

[herohog]

From THE source for all things Largo: 9mmlargo.com

In 1996 Winchester introduced a new cartridge, the 9x23mm Winchester. The exterior case dimensions of this round are almost identical to the 9mm Largo. Interior dimensions are different though, as this cartridge is loaded to much higher pressure than the 9mm Largo. For this reason 9x23mm Winchester ammunition should not be used in 9mm Largo firearms. Reloading the brass to 9mm Largo specifications should not pose a problem, if it is remembered that the case capacity of the 9x23mm Winchester is less than that of the 9mm Largo and powder charges are adjusted accordingly.

 

[Mastiff]

I keep on running into comments like this as I do my research:

ROBERT W. XXXXXX

Posted on Wednesday, July 24, 2002 - 2:45 am:
IS THERE ANY WAY TO FIND OUT FOR 100% SURE IF A PISTOL IS A 9MM LARGO VS. A 38 SUPER, WHEN WE BOUGHT MINE IT WAS SOLD AS A 38 SUPER AND WE HAVE FIRED OVER 2,500 ROUNDS OF SUPER AMMO IN IT AND HAVE HAD NO PROBLEMS AT ALL, I RELIZE THAT THIS DOESN'T MEAN SOMETHING COULDN'T GO WRONG, I WOULD JUST LIKE TO KNOW FOR SURE WHAT IT IS. ANY HELP WOULD BE GREAT, ALSO, CAN I GET PARTS FOR MY SUPER? ARE THEY INTERCHANGABLE WITH OTHER STAR MODELS?

 

[ButchG17]

Mad Magyar says:

They are not even close to identical.

Well, 9mm NATO ball lists a 112 grain bullet at 1263 fps.

And here are chronographed 9mm Largo velocities from http://www.9mmlargo.com/cartridge/chrono/velocity.htm

Granted 9x19 ammo varies quite a bit depending on who makes it and what they make it for, and 9mm Largo can certainly be loaded to higher velocity levels depending on what gun it's going to be used in, but overall, they look pretty similar to me!

 

[Starter52]

I still agree with Butch.

I owned a Star 9mm Largo and shot it for two years. I then replaced the 9mm Largo barrel with a 9mm Luger barrel. Same magazine, same recoil spring.

The Remington 9x19 ammo I used for the next six years had the same recoil as the 9x23 Largo. I could not tell one from the other.

 

[Jim Watson]

Many of the Spanish pistols are marked 9mm/.38.
This stands for 9mm Largo and .38 ACP; Spain's adoption of the 9mm Bergman predates Colt's introduction of the Government Model for the .38 Super in a heavier load than the old parallel ruler guns of 1900, 1902, and 1903 would handle.

A gun so marked will have a breechface and extractor wide enough for the semirim of the .38 ACP. If not so marked, it may or may not accept .38 ACP, depending on manufacturing tolerance.

So the question is, does a 9mm Largo have enough strength in reserve to handle .38 Super? Mastiff says his does. And current standard brand .38 Super is not as hot as used to be listed. Have they reduced the load or just gone to truth in advertising?

 

[FEG]

9mm Largo specs have changed dramatically over time. The Campo Giro and early Star pistols were not robust. As the Star metallurgy and design improved (Super A and Super B) the 9mm Largo loads became stronger.

Old 9mm Largo is essentially 9x23mm Bergman-Bayard, which is slightly weaker than 9x19mm Para. Newer loads are more comparable to lower-end 9mm +P. The "inexpensive" (relatively inexpensive) commercial ammo is generally weaker than the loads used by the Spanish military near the end of the 9mm Largo's life as their service cartridge.

This information comes from Speer #13 and #14.

 

[jjohnson]

Largo vs .38 Super

Well, interesting topic (this is especially for you, Mastiff). I think this is another "it depends" on power level of a Largo. I destroyed a Destroyer carbine years ago with loads that I didn't THINK were too hot for it, and they weren't loaded nearly to 9x23Win pressures :banghead: The bolt peened to where the action stuck.

I've shot thousands of reloads based on .38 Super brass with proper 9mm Largo loading data (read: warm 9x19 loads). No malfunctions handling the little rim on the Super cases, and my Star Super isn't marked 9/38, either.

Is there a consensus, though, that a Star Super can really handle the 9x23Win performance levels? I had never heard that they'd been tested for anything hotter than .38 Super, and I've been reluctant to even push that far.

Any more loading data out there from you other Largo lovers who've pushed it a bit warmer?

Thanks!

 

[FEG]

Everything I have read suggests that you should never load Largo to 9x23mm Win specs, nor should you shoot 9x23mm Win in a Spanish pistol chambered for 9x23mm Largo. I'm not going by experience or guesswork, just published warnings.

 

[Mastiff]

I got into shooting 9x23 Winchester through my Star Super A due to a series of posts by Clark, who posts here (see below). I then researched his statements, and decided that he was correct.
John Ricco designed the 9x23 so that competitors using the 38 Super could make major power factor using their unmodified 38 Super guns. The brass is the strongest centerfire handgun cartridge made. The web can sit out over an unsupported barrel and never bulge under that 50,000 CUP pressure. The brass is what is holding the pressure. The web is twice the thickness of the 38 Super.

Edit: The 1982 edition of Gun Digest had an article by Wm H. Smith, where he reviewed the Llama and Star pistols. He used 38 Super in these pistols with no problems with 38 Super power levels. He even stated that the 38 Super was the best substitute for 9mm Largo for American shooters. This was on page 200.

From http://www.thehighroad.org/showthrea...t=tokarev+9x23
It is Post #21

CAUTION: The following post includes loading data beyond currently published maximums for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The High Road, nor the staff of THR assume any liability for any damage or injury resulting from use of this information.


**************

I also have converted a Star Super B.
That pistol frame with long enough magazine for 9mm Largo, but is chambered for 9x19.
I converted one for 9x23mm and have been shooting it with
158 gr LSWC, 10 gr LONGSHOT, 1.129"
In contrast, Hodgdon in 2002 showed for maximum load for 357 magnum:
158 gr HNDY XTP JHP, 8.4 gr LONGSHOT, 1.580" 1394 fps, 43,200 c.u.p.

To deal with heavy recoil, I reamed out the recoil spring coweling of the Star slide from .431" to .4375", to use a spring from Wolff gunsmith pak #14 with OD = .433". More can be reamed out and a still better spring can be used, the guide rod must be reduced in diameter.

 

[jjohnson]

38 Super in Largo Star Super

Hm.... well, I may try that very carefully, Mastiff.

I called Starline some months ago to ask them about using their 9x23 brass as a sub for the Largo brass bearing in mind that I'm hanloading to pressures below the published 9x23 range They said that from their perspective, the dimensions were so close that it should work - and I've proven that in my Star Super they work just fine, as do .38 Super cases.

I've seen some of Clark's posts, and regard them as good data. What I'd like to explore is using a 9mm Luger barrel made for a CS52 as basis for a 9x23 conversion - thinking that maybe the CZ52 might be stout enough for at least 38 Super pressures. I'm not ready to go loading hot 9x23 Winchester loads in either a Star or a modified CZ52 - I don't think they were built with that sort of use in mind.

I think I'll go order a new spring from Wolff and start carefully warming up the loads in the Super. The info on the brass is helpful - of course, with more brass, there's less capacity, so there would be a corresponding rise in pressure, so I'll be mindful of that when using 9x23 cases as Largo or 38 Super substitution. I'd like to get good performance without doing anything too risky.

 

[Mastiff]

I wouldn't use the CZ-52 barrel. The CZ-52 barrel is relieved for the rollers in the CZ-52, this makes a portion of the barrel EXTREMELY thin. Again, this is from Clark:

" The CZ-52 uses a 8 round single stack mag. It utilizes a roller
locking system to safely use all sorts of Tok ammo, from less powerful
loads for the Tokarev pistol, to very powerful loads meant for this
handgun (Czech M48 round) and also for PPSh submachine guns."

When I destroyed two CZ52 pistols in 2000 with experimental handloaded
overloads, and then could not harm Tokarevs with much higher overloads,
I found the weak spot, the bottom of the CZ52 chamber was very thin,
[.058" CZ52, .125" Tokarev], because the underside had been milled out
to make room for the roller blocks. I began to question the premise that
the CZ52 is stronger commonly printed in books, magazines, ammo
manufacturers etc., though out the gun culture.
http://www.thehighroad.org/attachment.php?s=&postid=249178

This is what I now believe probably happened to get this error into the
gun culture:

continued at http://groups.google.com/group/rec.guns/msg/d62d4ad3fb4c4cb6