Well tried to get out today for a bit and in between rain I was able to try out some of the Sargent Major ammo. I just got a case in yesterday and ran to range with 120 rds and a couple of different rifles.
So , the initial run with a 16" suppressed upper ran fine and gave me about a 3" group at 100. Next up was a brand new MK18 mod 1 clone , and it choked on it. Basically fired fine , but not enough " ummpff "to eject and cycle it. I did not shoot for accuracy , but was hitting a steel plate at about 65 yards with no issues. I could get maybe two or three rounds off , then it would fail to reload.
It looks very similar to Silver Bear and reacts bout the same and is ok ammo for just banging around with.
As a side note I hade some old surplus Brit ss109 that has always functioned fine for me in a number of rifles , but would not cycle the mk18 clone.
For .40 a round delivered the SM ammo was ok and would buy again if the price was right and to keep the good stuff held back.