Options
a)the reporter is wrong.
b) the gun is 30mm but of a low rate of fire to preserve the barrel.
c)the gun is 30mm but uses low power ammo to preserve the barrel (ie grenade rounds not cannon rounds)
d) the gun is 30mm but has a small magazine to preserve the barrel.
e) the gun is 30mm and china has developed a super alloy
f) the gun is 30mm but the gun is replaced after every use.
g) combinations of any of the above save for a.