The 7.62 mag issue is a whole different animal.
The 5.56 mags are standardized across all manufacturers, while 7.62 mags are made to different specs depending on the manufacturer and/or rifle platform. Specs for the MVP Patrol in 7.62 list compatibility with M1A/M14 as well as DPMS LR-308/Knights Armament SR-25 mags. These two types of magazines are typically not cross-compatible.
Magpul specs for their LR/SR 7.62 Pmags list compatibility with LR-308/SR-25, but specifically call out that they are not compatible with rifles that use M1A/M14 mags. Looks like Mossberg's attempt to straddle the fence on compatibility has created a design flaw that somehow causes an issue for the 7.62 Pmags...
The 5.56 mags are standardized across all manufacturers, while 7.62 mags are made to different specs depending on the manufacturer and/or rifle platform. Specs for the MVP Patrol in 7.62 list compatibility with M1A/M14 as well as DPMS LR-308/Knights Armament SR-25 mags. These two types of magazines are typically not cross-compatible.
Magpul specs for their LR/SR 7.62 Pmags list compatibility with LR-308/SR-25, but specifically call out that they are not compatible with rifles that use M1A/M14 mags. Looks like Mossberg's attempt to straddle the fence on compatibility has created a design flaw that somehow causes an issue for the 7.62 Pmags...