Default [Q] Can I go from MK6 to MJ4 bootloader?

Just wondering if II need to go to a different bootloader on my AT&T sgh-i317 Note 2 with KitKat 4.3? My current is MK6...should I go to MJ4 as I can't flash any rom or OTA upgrade to kitkat 4.4.

Is it possible to go back with bootloader and then try to upgrade to kitkat 4.4 or is this risky?