I was firing these bb's from both the mp5 PDW and my CA m15. Both guns got a jam with these bb's. Or maybe its coincidence. Either way, ill use em up and go back to the KSC and MT ones ive been using. Trial and error and sticking with what works is name of the game for me with this. Never had any issues with those ones.
Pull it back a bit Amos, I know what it is im useing.