The bergmann is listed as a mid 30kpsi cartridge.
the largo is listed as a 18k psi round

the destroyer is marked 9/mm bergmann!!

I've always "known" the largo and bergmann to be interchangable... and the destroyer is marked with the higher pressure of the two.

it doesn't REALLY matter, as i am sending the bolt and action off to be heat treated, anyway

Might find something in these articles Many sources say they are alternate names for the same cartridge.

http://www.9mmlargo.com/destroy/destroy_art.htm

http://www.9mmlargo.com/destroy/index.htm

http://en.wikipedia.org/wiki/9x23mm_Largo

http://9mmlargo.com/cartridge/index.htm


Bruce

Thanks Bruce .. I have read those .. and emailed the guys at quickload to find out

While the 2 have the same external dimensions, as you noted the operating pressure is quite different.

There are a number of cartridges that share similar issues, and a couple of them have caused quite a few internet arguments (308Win & 223 Rem vs 7.62 & .556 NATO). 38 Auto (not 380) and 38 Super is another one.
Running Largo ammo in a Bergman rated gun won't cause any damage, but might not cycle the action, but running Bergman ammo in a Largo firearm would at a minimum cause excess battering of the frame/slide and on the other extreme could disassemble the weapon for you.

Blowback weapon design is a balancing act between bolt thrust energy and barrel time vs breach inertia and springing. Lower the thrust (chamber pressure) and you may not move the breach far enough to cycle. Raise it and you overdrive the breach and beat up the frame.
Even the delayed blowback / locked breach type designs can show the same problem (see the need to "re-spring" a 1911 to reliably cycle bulls-eye target loads

TG,
its a bolt gun marked 9/mm bergmann ... i fully understand pressure and improper carts in them .. cetme rifles, for instance ..

i am trying to find out if the TRUE pressure of the bermann is ~38k

I keep finding references that say the Largo and Bergmann are the same, and the Steyr is the high pressure loading of the 23mm case, but never any data to back it up.

This is the best article I've found, and it looks like they are all a little different. But dimensions and performances are so close pressures can't be drastically different.
http://czechpistols82792.yuku.com/topic/14702

"Military 9mm Largo loads generally have a nominal velocity of 1,100 fps with a 125gr bullet. The original bullet diameter was .354, and the earliest loads with this bullet diameter appear to have been slightly weaker. By 1913, 9mm Largo loads had a bullet diameter of .355, or the same as 9x17mm, 9x19mm, 9x21mm, and the other 9x23mm cartridges. After WWII, 9mm Largo loads often pushed a 125gr bullet as fast as 1,200 fps, which raises pressures past the 35,000 psi mark. "
------------------

"Dimensionally, 9mm Bergmann-Bayard is virtually identical to 9mm Largo, but it is slightly bigger all over. For example, 9mm Largo cases are 22.99mm long, while 9mm Bergman-Bayard cases are 23.11mm long. The overall length of the Bergmann-Bayard cartridges are always a minimum of 0.5mm (.02) longer. Bullet and bore diameters in 9mm Largo are typically .354-.355. In 9mm Bergmann-Bayard, bullet and bore diameters can be as large as 9.06mm (.357).

9mm Bergmann-Bayard has a nominal velocity of 1,100 fps with a 125gr bullet. Typical bullet diameter was .355, which is the same as 9x17mm, 9x19mm, 9x21mm, and the other 9x23mm cartridges. The change from .354" to .355" bullets in 9mm Largo appears to have occurred roughly at the same time that 9mm Bergmann-Bayard was introduced."
--------------------
"Military and commercial loadings of 9mm Steyr had a nominal velocity of 1,200 fps with a 116gr bullet. "


CIP (Europe's SAAMI) only lists one 9x23mm cartridge, a 9mm Steyr, with no other name.
http://www.intermin.fi/intermi...C/$file/TABIVcal.pdf

Bruce

quote:

Originally posted by jeffeosso:
TG,
its a bolt gun marked 9/mm bergmann ... i fully understand pressure and improper carts in them .. cetme rifles, for instance ..

i am trying to find out if the TRUE pressure of the bermann is ~38k

Ahh
It wasn't clear in your OP that you were only interested in the pressure spec. And here I was simply thinking of the problems that mixing them would cause in a self loader.

thanks guys .. that helps alot .. thw gun is marked bergman, not largo .. and made in the 50s.. i may send it off to heat treat anyway!