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

The L7A1 does increase cyclic rate.  Considering that the L7A1 is a 124 gr. bullet moving at 1450 fps, only desperation would drive me to fire this stuff in any pistol (except maybe a Lahti).

Wow, that's some hot stuff. Thanks for the numbers.

Ran into a guy at the quarry today that had some thick plastic that was rated to stop .38 and 9mm rounds. He was using a 9mm carbine and had some different ammo, and none of it would penetrate the plastic. Gave him some L7A1 Hirtenberg, and the stuff blew right through it. Pretty cool.

Bought a can of Hirtenberger L7A1 a couple years ago. Great stuff for the UZI Carbine. Wonder what the velocity would be coming out of a 16" tube ?

Great info, thanks for the specifics on the various 9mm ammo. I wonder what the Olympic 124-gr NATO would chrono at? Based on shooting over 1,000-rds of this stuff, I doubt that the numbers quoted by the Sportsman's Guide on their website are accurate at 1,251 fps and 431 ft/lbs. I would guess it more at 1150 fps and considerably less on the ft/lbs number.

I have a case of that Hirtenberger 124-gr +P+ ammo and it will give you a real jolt when fired from a Kel-Tec Sub2K carbine or an Olympic CAR-97 in 9mm. It feeds and cycles very well, though. It is a real fistfull when fired through a Glock 17L, which seems like it can digest just about any 9mm out there. With the 124 gr bullet taking up so much room in the 9mm case, they must use some very special high-potency powder to get that kind of speed out of that round. Hot Stuff!!