M-39 cracked frame

[Drm50]

Back in 1969 or 70, I bought a M-39 and a Browning Hi-power
the same day, new. At a gun show I bought a case of 9mm ball
military surplus, French. The Hi-power would not strike hard enough to fire this ammo. The 39 had no troubles at all, until
the frame cracked! The same type of crack that shows up from
hot loads in m-52 . My gunsmith ask me to look at ammo and
told me that it was intended for use in blowback operated sub-
machine gun, to hot for alloy frame. Beware of what you feed your thumb buster, it ain't cheap in the long run. I was young
And dumb at the time!

 

[LVSteve]

9mm surplus subgun ammo is still out there to bite the unwary. IIRC the last lot that was readily available was made by Hirtenberger. Some folk were shooting it in CZ-75s with mightily uprated recoil springs.

 

[Jaymo]

Was the Hirtenberger 100 grain soft point+P+ subgun ammo, or not?

 

[bmcgilvray]

"The same type of crack that shows up from
hot loads in m-52 ."

You're firing hot loads in a Model 52?

Inquiring minds want to know why.

 

[Jaymo]

"The same type of crack that shows up from
hot loads in m-52 ."

You're firing hot loads in a Model 52?

Inquiring minds want to know why.

Especially with that whopping 8 pound recoil spring.

 

[LVSteve]

Was the Hirtenberger 100 grain soft point+P+ subgun ammo, or not?

I don't think so, I seem to recall that GSG 9 used it in their Glocks.

The subgun stuff was a special UK order known as L7A1. Supposedly it was 124gr FMJ good for 1500 fps from a Sterling. Grabbed this info from another forum. The test after the BATFE warning is quite instructive.

Department of the Treasury
ATF Office of Public Information

For Immediate Release FY-97-6
Contact: Vickie Saunders Date: November 7, 1996

HAZARDOUS AMMUNITION

Washington--The Bureau of Alcohol, Tobacco and Firearms (ATF) has been advised by Hirtenberger AG, Hirtenberg, Austria, that certain 9Xl9 mm
caliber ammunition produced by Hirtenberger is unsafe for use in any handgun.

The ammunition, designated L7A1 and produced ln the years 1990 through 1992, was produced for the British Ministry of Defense specifically for use in submachineguns under adverse conditions. The ammunition was loaded to produce pressures far in excess of that intended for use in handguns.

The manufacturer advises that up to 12 million rounds of this ammunition has recently been sold on the world surplus market. The ammunition can be identified by the following head stamp located on the bottom of the cartridge case

12 O'clock position: HP
3 O'clock position: 90, 91, or 92
6 O'clock position: L7Al
9 O'clock position: the marking of a cross within a circle

This ammunition should not be fired.

We are not aware of any of this ammunition being imported into the United States. ATF will take action to prevent the commercial importation of this
ammunition.

For additional information, contact, Mary Jo Hughes, Chief, Firearms and
Explosives Imports, (202) 927-8320.

Hirtenberg L7A1 test results
Conditions: Partial overcast, 70 deg F., light winds, elevation 7000 ft. (NE of Flagstaff, AZ)

Equipment:
Oehler chronograph with proof channel.
Sterling SMG, 6.5” barrel
Browning Hi-Power, 4.7” barrel

Velocity data (fps) are reported in this order:
High velocity, low velocity, velocity spread, average velocity and standard deviation.
10 rounds fired per group.

Fired in the Sterling SMG (semi auto):

L7A1 Hirtenberg, 124 gr. FMJ

1474 1421 53 1450 17

Federal American Eagle, 123 gr FMJ

1197 1159 38 1178 15

S&B 115 gr. FMJ

1306 1274 32 1289 9

Canadian WWII, MM45, 115 gr. FMJ

1402 1321 81 1367 27

Winchester WWII, WRA 42, 115 gr. FMJ

1332 1277 96 1345 27

Federal 147 gr. JHP

1072 1028 44 1054 14

For comparison, these were done with a T-series Hi Power:

Federal American Eagle, 123 gr FMJ

1070 1108 38 1088 16

Canadian WWII, MM45, 115 gr. FMJ

1247 1279 32 1268 11

 

[Drm50]

I didn't mean I shoot hot loads in M-52s. When looking at used 52 I always check frame. I think back when you could buy 52s, people would
single load what ever 38 sp they had, if it went off they were happy. They
knew only WC would fit mag,but didn't realize they were wrecking gun. I
have never seen a S&W that shot better with hot loads, why beat gun?

 

[lhump1961]

I didn't mean I shoot hot loads in M-52s. When looking at used 52 I always check frame. I think back when you could buy 52s, people would
single load what ever 38 sp they had, if it went off they were happy. They
knew only WC would fit mag,but didn't realize they were wrecking gun. I
have never seen a S&W that shot better with hot loads, why beat gun?

I constantly question why some feel the need to run the hottest stuff they can find. I can see no reason to try to make a 9mm feel like a .357 or to try to make a .357 feel like a 44mag. If a person wants a huge bang and a nuclear fireball then get a 500 and have at it. I load and shoot my guns the way they were intended.

I have a couple of 39's and like them too much to abuse them.

 

[inventorguy]

Back in the 1960s I had a nice Model 39. I was concerned about the service life, especially of the aluminum cam surfaces in the frame that forced the barrel to unlock during firing. The president wrote back and stated that I should not worry. He wrote that they had fired a Model 39 with 5000 (five thousand) definitive proof loads and there was no adverse effect on the frame.

 

[ibewbull]

Back in 1969 or 70, I bought a M-39 and a Browning Hi-power
the same day, new. At a gun show I bought a case of 9mm ball
military surplus, French. The Hi-power would not strike hard enough to fire this ammo. The 39 had no troubles at all, until
the frame cracked! The same type of crack that shows up from
hot loads in m-52 . My gunsmith ask me to look at ammo and
told me that it was intended for use in blowback operated sub-
machine gun, to hot for alloy frame. Beware of what you feed your thumb buster, it ain't cheap in the long run. I was young
And dumb at the time!

The Browning / P35 should not be
used with SMG or +p either.

Some have converted the .40 High Powers to 9MM for +P ammo.

If I want more than standard 9MM power I will shoot my .38 Super Combat Commander. Or my .357 S&W.

 

[paulj84003]

FYI, back in 1974 our department purchased several hundred mod 59's. After initial break in with factory rounds, they then used commercial reloads for training, and WW silvertips for carry. In 1984 during an annual inspection I discovered a crack in the frame of one 59. The crack was at the left rear corner of the magazine well continuing into the relief cut of the safety lever in the frame. The magazine well rear corners were not radius-ed but sharp 90'. These sharp corner's produced stress risers and eventually cracks. I took 20, 59's that had been issued to uniformed officers since 1974 stripped the frames, took them to the Cal National Guard hanger in Fresno and submitted them to the Zyglo process to determine if the frames had cracks. Every frame of this group either had a crack or was ready to crack, either on the left or right rear corner of the magazine well. These were all in the serial number range of 172000
thru 174000 Required shooting was quarterly First quarter factory loads remaining quarters reloads.