Brian, I have this headstamp in a round that has a total weight of aout 183 grains, which is likely loaded with a 115 grain bullet at that weight. I have not seen the 124 grain suppressor load before, unless there is such a reduction of the powder charge that it reduces the weight from the norm of a complete cartridge weight of about 192 to 194 grains. That doesn’t seem likely to me with pistol powders, as the difference would about equal or exceed the complete weight of most 9 mm powder charges, if my memory serves me correct (for once). I have not loaded any 9 mm Luger for about 30 years - counting labor it has just been cheaper to buy it - so I could be off a bit.
Can you supply a total cartridge weight of the cartridge you posted just for comparison? Thank you.
Edited once to correct a typo in bullet weight.