Got proof of that

Times have changed
Mossberg offers bolt-action, lever-action and auto-loading rifles as well as pump-action, auto-loading, and over/under shotguns. Manufacturing is done both in Turkey and in the US from parts made in both America and Mexico.
PUMPS are USA. others are imported or parts there of remember there are like 12 versions of the 930 alone
The truth
The 930 was designed and built from the ground up as a budget shotgun. It gets people into a semiautomatic shotgun for slightly more than a good pump. In order to do this Mossberg relied heavily on MIM manufacturing of all small internal components, and designed a cheap to make gas system. There are generally the light users of the shotgun, and then competition shooters or hunters that fire thousands of shells a year.
Light use common problems are going to be gas system maintenance. Shooting the gun especially with common dirty bulk ammo found in big box stores and then leaving it to sit can result in lots of hard deposits, and plastic in the gas system. Regular cleaning helps keep things running well. Early models had some issues with gas cylinders being slightly cocked causing cycling issues.
Heavy user problems start to become far more complex. Gas and recoil system need mods to keep up with heavy use. Or3gun spacer tubes, ans SBE Precision Products pistons really bring the reliability and reduced carbon buildup in the gas system to another level. Small parts start breaking in heavy use guns. Extractors, charging handles, shell latches usually break eventually so keep spare parts handy.