With a slight modification, it should work. the trigger spring set up is different between the MT6 and MX12. The MX12 uses a shorter, skinnier spring that I believe fits in a recess in the trigger plate and pushes against a flat surface on the top of the trigger blade. The MT6 has a spring that sits in a recess drilled into the top of the trigger blade. If you drill a recess in the top of the MX12 trigger blade, it should work. See pics. Blued trigger is MT6, silver trigger is MX12.