what calibers did they come in a friend just picked one up it was sold to him as a 9mm 9x19 he shot a couple of magazines of 9mm out of it a a few weeks ago and he said the it worked ok
for a few rounds the it would not cycle I looked at the barrel and it's has 9x21 stamped on it i have tried to look up
if it was chambered in the 9x21 with no luck so anyway any thoughts