No way to know unless you buy some and fire it. I have had good experiences with all of Magtec products, primers, brass , bullets and a few boxes of +p 115gr hollow points, they were very + by the way, no reason to beleive the 124's wouldnt perform to the same standards as their other products. But as far as feeding you have to buy a few hundred and try them. Cause even if they worked in mine or a hundred other guns you can never be sure unless you try it.
Hello. As has been stated, there's just no way to know for sure if the MagTech is reliable in your pistol w/o your firing it in that pistol with the actual magazines to be used in it.
From two 9mm Hi Powers w/factory bbl's, this round averages right at 1100 ft/sec.
When fired into water, the bullet would sometimes seem to explode and whether fired into water or wetpack, the bullet's jacket would usually fragment, much the way some other JHP's do, albeit at higher velocities.
When the bullet acted "normally", this was a typical result, but sometimes, the bullet and jacket simply seemed to shatter. This bullet penetrated right at 8" in wetpack, which should be about 12" in 10% calibrated ballistic gelatin.
It would probably "do" as defensive ammunition but I'd personally like to see a bit more consistency before I bet the farm on it. These tests were done in 2004 for a book on 9mm ammunition I was writing and it is possible that the "brittle" characteristics have been taken care of. You could find that out easily by doing a wetpack test of your own.
If you do, please report back your observations if not too much trouble.
If it turns out that the round does not feed, you might take a look at Remington's 124-gr. "Express" JHP as well as Federal's classic 115-gr. JHP. Both of these standard pressure loads frequently feed reliably in older Hi Powers...and both can be had at higher pressure levels if desired.