.380 vs. 9X18 Ultra


March 29, 2004, 11:36 PM
Can I safely use .380 ammo in a pistol chambered for 9X18 Ultra? :confused:

I note that the 9x18 Ultra case is .02 mm larger in radius
and 1.2 mm longer, all other measurements being equal.


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March 30, 2004, 12:20 AM
Do you mean 9X18 Makarov?

The 9X18 Mak round is really a 0.365 diameter (instead of the standard 0.355 for other 9mm)...

Could you shoot a .380 round in a 9X18 gun? Yes

Is it a good idea? No, it's bad for the gun and I would guess that accuracy would be non-existant...

March 30, 2004, 08:47 AM
I remember reading about the 9x18 Ultra, I believe it was marketed to European police agencies at one time. It's not the same cat as the 9x18.

Though I believe David's advice applies to the Ultra as well, I am interested to hear the opinion of others.

March 30, 2004, 08:49 AM
Not sure it'd be a good idea, as it'd be headspacing on the extractor.

March 30, 2004, 10:11 AM
9x18 U-l-t-r-a

A 9x18 Ultra weapon won't chamber a 9x18 Mak round. Period.

It will chamber and eject a .380 round, but I'm not willing to pop the cap 'til I know more.

So, if you KNOW ;) whether or not this is safe, please let me know.


March 30, 2004, 06:00 PM
So, if you KNOW whether or not this is safe, please let me know.
i don't empirically KNOW, but my theorectical KNOW says .380/9mmPolizei has the same problems as .40/10mm or 9mm/9x23mmWin

March 30, 2004, 06:06 PM
I've never heard of this, What kind of gun is this?

I first thought you were talking about a MAKAROV round but I guess not.

You have me curiouse.

March 30, 2004, 09:05 PM
So, if you KNOW ;) whether or not this is safe, please let me know.

I KNOW it'd be headspacing on the extractor, which is not a Good Thing. ;)

March 30, 2004, 11:20 PM
Jedi, the 9mm Ultra was developed by the Germans during WW2. It is my understanding that it is basically a .380 with a case that is 1mm longer. (.380=9x17, 9mm Ultra=9x18) It never went anywhere at the time, but it was reintroduced in the '70s by Walther who renamed it 9mm Police and sold the PP Super which fired it. IIRC, SIG also offered P230s in this caliber.

March 30, 2004, 11:56 PM
but the real interesting thing about 9mm Ultra is it was developed as the most powerful thing you could fire from a fairly compact pistol in a blowback action. SIG P-230 was chambered in it as well as a few Walther PP Supers. the Makarov and it's 9x18mm round is based partially on WWII german research acquired by the Russians and i think they succeded in combining german efficiency with russian durability and reliability. if you're limited to FMJ by the Hague Accords 9mm Makarov or 9mm Ultra matches 9mm Parabellum because it tends to overpenetrate.

the 9mm Ultra fires a 100grain bullet at about 1000fps
specialized 9mm Makarov loads fire a 109 grain bullet at about 1015fps

The Italians attempted a most powerful blowback cartridge earlier in the 9mm Glisenti (just a 9mm Para downloaded originally to be used in Glisenti pistols and later early Beretta automatics).

March 31, 2004, 09:19 AM
The Ultra chambering is nice for collectors but thats all its good for IMO.

The Mak loads from Russia have surpassed it in performance......Wolff, Barnaul etc........Corbon should bring it back........AARRGGHHH!

Years ago I bought an Accutek
9mm SubCompact that was a blowback design.......just delayed enough to make it work. Theoretically work that is.....it never did and I never kept it.

Shoot well.

March 31, 2004, 10:46 AM
When it come to firearms,

"When in doubt, Don't."

February 3, 2011, 11:03 AM
It is not safe to shoot .380 in a 9x18 ultra or police .Load it and shake the gun ,you can hear the ammo ratteling in the chamber ,so no it aint safe. 9x18 ultra or police can be gotten from Sportsman Guide or other sources. Get the right ammo,it is not worth destroying the gun or worse ,yourself

February 3, 2011, 02:44 PM

You might find this thread useful. As long as the extractor holds the cartridge firmly against the breechface, it should be ok, other than the action might not cycle. If the round is loose and rattles around, you have the chance to get case separations and peening of the breechface. The rule of thumb is there should be no more than 0.006" free space between the case head and breechface in high powered shouldered rifle cartridges. A straight walled blowback pistol cartridge operating at 17k psi isn't going to be nearly as intolerant. As this pressure, a case separation is extremely unlikely, IMO. Peening of the breechface would be my main concern, particularly with such a rare, possibly collector gun.

One other thing to watch out for is the extractor grip. On some blowback pistols, the extractor barely keeps a hold of the cartridge, at all. When the FP strikes, the cartridge might jump forward, creating more headspace than you anticipate.

I doubt 0.02mm difference in radius at the case head will be a problem, as long as you don't fully resize and reuse the cases multiple times. Afterall, many people have admitted to shooting .380 ammo in a mak which is a much larger difference, and worst problem I've heard of as a result is a split case that was difficult to extract.

But these are just my opinions and are not based on actual experience.

February 3, 2011, 06:42 PM
Can I safely use .380 ammo in a pistol chambered for 9X18 Ultra?

Yes. I would also recommend the use of brass-cased ammo, exclusively. Steel-cased ammo use I will not recommend.

What might happen if using .380 ammo with a 9x18 U magazine is that occasionally, it will misfeed the first round. For some strange reason, the remaining rounds feed just fine. That problem can be avoided by using a .380 magazine.

Works just fine with the Walther PP Super, Benelli B-82 and Sig P230. The proof's in the pudding with those three models and is as simple as this. Get a good working model. Take the slide off. Insert a cartridge of .380. See how it is chambered. Extract and insert a 9x18 U cartridge. Notice any difference?

Then slide a .380 under the extractor. Try to wiggle it around. Repeat with a 9x18 U. Notice any difference?

Simple as this. You have to have the three models, .380 ammo and at least one 9x18 U cartridge. Then you'll know for certain.

Btw, if the rounds wiggle under the extractor you need to have it tuned. It's not then an issue with the ammo, rather, with the extractor.

Fwiw, a loading of a 123 gr. bullet traveling at 1050 fps. can be achieved with the 9x18 U. For that I recommend using a trimmed .38 Super COMP case. No .380 is built to handle that.

February 3, 2011, 09:09 PM
Is there a sudden interest in the 9mm Ultra lately? This is the 2nd 6-year-old thread about the 9mm Ultra dug up from the deep in the same day.

April 1, 2011, 01:20 AM
Finally got a box of 9x18 ultra and shot my Walther PP Super . Man,blows a .380 away . excellent penetration, powerfull,as far as shooting 380's in a gun chambered for a 9x18 Ultra ,No If it isn't made for it don't do it . Would you shoot a 7mm Remington in a Jap 7 mm. No

April 1, 2011, 01:38 AM
Would you? No. Would the gun take the pressure? Yes. But that's beside the point, because the chambers wouldn't match.

How much did that 9x18 Ultra set you back? I can imagine it was quite a bit, since I know it's rather rare and expensive. Makes me glad that good commercial 9x18 Mak ammo is easy to come by since I've got 4 Mak-caliber pistols to feed.

April 1, 2011, 03:58 PM
According to QuickLOAD, I can safely load a Hornady 100gr FMJ-Encapsulated bullet at more than 1100 fps out of my Beretta 86 (.380 Auto with a 4.37" barrel) with a couple of different powders. So I'm pretty sure a 100gr jacketed bullet at 1000 fps is very possible in the .380 Auto platform. Thus obviating the need for an 9x18 Ultra.

Not that I've actually done these things, mind you. But handloading does open some intriguing opportunities for the adventurous (see "Clark"...).

April 1, 2011, 06:13 PM
Had never heard of this caliber before; momentarily jumped to thinking this was an April Fool's Day joke, what with there being no shortage of other 9mm ammo choices to go around (Mak, kurz, parabellum, etc) ...


February 26, 2012, 12:40 PM
You cannot use .380 cartridges in a 9mm ultra chambered firearm. For one simple fact, the .380 bullet is larger in diameter, and if the barrel is held within a tight tolerance, you may get a catostrophic malfunction in the chamber which may injur you, and will more than likely damage the firearm. 9mm ultras are their own type of ammunition, so only use 9mm ultra in 9mm ultra chambered guns. That being said, 9mm para- 9mm MAK- and 9mm ultra are not interchangeable. Always use the correct ammo.

February 26, 2012, 12:49 PM
Weasle, I see you were the one to bring back this thread from the grave. Just a small point of forum ettiquete but it's not generally done once something gets to be more than a year old.

You'd have been better off to start a new thread about your ammo and gun.

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