Aero Precision M5 Lower Parts Compatibility

[Sir John of Dough]

I received the following response from Aero Precision regarding fitment of aftermarket parts in their M5 lower receiver as I'm in the process of building my first .308AR:

"Due to the non-standardized platform, I cannot guarantee that any other manufacturer's AR10/AR308 product will work in our M5 platform.

The listed bolt catches are all AR15 sized (edit: I had inquired after compatibility of Strike Industries' Enhanced Bolt Catch and Extended Bolt Catch), and we have an M5 bolt catch that will work specifically for the wider area of the receiver so the AR15 sized bolt catch will not work and I can only guarantee that our M5 bolt catch will work.

The magazine catch body is mil-spec AR15 sized, so most aftermarket mil-spec sized catch will work you just need an extended mag release button (0.5") and thread it on halfway.

The safety selector is AR15 mil-spec sized so most mil-spec sized ambi safety will work.

The Firing Control Group will be the same mil-spec assembly as well, the lower will take trigger/hammer small pins (.154") and most aftermarket mil-spec triggers will be able to fit; I cannot guarantee a 100% chance of fitment for cassette style (drop-in) triggers as sometimes the housing will interfere with fitment in our trigger well. Let me know if you have any other questions or concerns."

Best Regards,
Cong Le
Support team,
Aero Precision

[98Z5V]

I support everything that Aero Precision told you. 

[dpete]

I can vouch for the Phase 5 extended bolt catch working with an Aero 308 lower.  Had one on mine.  Same function as a Magpul BAD lever except its all one piece.  If you like the concept it definitely works.