9mm Largo

BoogieMan · April 27, 2012, 01:05 PM

i have a Llama that on ocasion I will take out just to pop some holes. I have picked up the brass and have found a shell or 2 over time that has a crack near the base. My Dad (no longer with me) had always said that they were a hot round and that caused the problem. My assumption is that its the 70 y/o ammo. Anyway, what are the balistics of these old rounds? Are they on the hot side? The gun (Llama Extra 1911 long slide clone) does have a fair recoil. Certainly seem to have more punch than a 9mm Luger but thats only my perception with nothing to base it on.

SHR970 · April 27, 2012, 05:28 PM

The 9mm Largo aka 9mm Bergmann-Bayard aka 9x23 (not to be confused with the 9x23 Winchester) runs a 125 gr. bullet at about 1200 fps. This is slightly slower that a standrard 9mm Parabellum. When Speer decided to manufacture ammo in this caliber, they held the MAP to 30k psi in deference to the older Astra 400s that were common in the surplus market then.

BoogieMan · April 27, 2012, 06:34 PM

Thank you for the info. I wouldnt exactly call that a hot round 125 gr at 1200 fps.
Casing splits caused by corosion or poor quality control?

SHR970 · April 27, 2012, 07:16 PM

70 yo ammo...powder may be deteriorating. By products of deterioration could be compromising the brass. Could also be bad brass, pressure spikes, or one of several other things...you are talking about some pre or WWII vintage stuff. God only knows how it was stored over the years before it came into your family's possession. Then there is the possibility of issues with the gun itself.

You might want to look into some younger ammo and try it. If the problem persists, the problem is in the gun itself. If the problem goes away, you know it's the ammo.

Hammerhead · April 28, 2012, 12:29 AM

I considered that caliber for a while, One thing I read was that some chambers were on the loose side. That may be contributing to the splits.

BoogieMan · April 28, 2012, 10:37 AM

It is an interesting caliber being such a long 9mm. I guess it was better developed as the 9x23 rather than the 9mm Largo. Has anyone seen modern ammo available? I rarly shoot the thing because the gun itself is horrible inacurate. Holds about an 18" pattern at 20 paces. It is smooth and oporates fine it just isnt any more efective than a deringer. More of a novelty that was left to me by my father. No value as a trade (maybe $50) so no sense in getting rid of the gun.

April 27, 2012, 01:05 PM	#1
BoogieMan Senior Member Join Date: April 4, 2012 Location: South Jersey Posts: 2,217	9mm Largo i have a Llama that on ocasion I will take out just to pop some holes. I have picked up the brass and have found a shell or 2 over time that has a crack near the base. My Dad (no longer with me) had always said that they were a hot round and that caused the problem. My assumption is that its the 70 y/o ammo. Anyway, what are the balistics of these old rounds? Are they on the hot side? The gun (Llama Extra 1911 long slide clone) does have a fair recoil. Certainly seem to have more punch than a 9mm Luger but thats only my perception with nothing to base it on.

April 27, 2012, 05:28 PM	#2
SHR970 Senior Member Join Date: January 24, 2011 Posts: 1,427	The 9mm Largo aka 9mm Bergmann-Bayard aka 9x23 (not to be confused with the 9x23 Winchester) runs a 125 gr. bullet at about 1200 fps. This is slightly slower that a standrard 9mm Parabellum. When Speer decided to manufacture ammo in this caliber, they held the MAP to 30k psi in deference to the older Astra 400s that were common in the surplus market then.

April 27, 2012, 06:34 PM	#3
BoogieMan Senior Member Join Date: April 4, 2012 Location: South Jersey Posts: 2,217	Thank you for the info. I wouldnt exactly call that a hot round 125 gr at 1200 fps. Casing splits caused by corosion or poor quality control?

April 27, 2012, 07:16 PM	#4
SHR970 Senior Member Join Date: January 24, 2011 Posts: 1,427	70 yo ammo...powder may be deteriorating. By products of deterioration could be compromising the brass. Could also be bad brass, pressure spikes, or one of several other things...you are talking about some pre or WWII vintage stuff. God only knows how it was stored over the years before it came into your family's possession. Then there is the possibility of issues with the gun itself. You might want to look into some younger ammo and try it. If the problem persists, the problem is in the gun itself. If the problem goes away, you know it's the ammo.

April 28, 2012, 12:29 AM	#5
Hammerhead Senior Member Join Date: May 31, 2004 Location: Minnesota Posts: 2,432	I considered that caliber for a while, One thing I read was that some chambers were on the loose side. That may be contributing to the splits.

April 28, 2012, 10:37 AM	#6
BoogieMan Senior Member Join Date: April 4, 2012 Location: South Jersey Posts: 2,217	It is an interesting caliber being such a long 9mm. I guess it was better developed as the 9x23 rather than the 9mm Largo. Has anyone seen modern ammo available? I rarly shoot the thing because the gun itself is horrible inacurate. Holds about an 18" pattern at 20 paces. It is smooth and oporates fine it just isnt any more efective than a deringer. More of a novelty that was left to me by my father. No value as a trade (maybe $50) so no sense in getting rid of the gun.