Help me identify what this is (on an LA AICS)

[Butters_Aus]

The part in question is the small piece in front of the trigger inlet in my LA AICS. Should be an image attached, just curious as to what this is as it's not in my short action version. (Shown closest to me in photo).

Any help identifying it and it's use greatly appreciated.

Regards
Nut

 

[MarinePMI]

Looks like an adjustable mag well, to tighten up the fit of the magazines. Not sure, just a hunch since I don't own a LA AICS chassis...

 

[Massoud]

It keeps the mag from going up too far into the action on the long actions.
Justin

 

[Butters_Aus]

It keeps the mag from going up too far into the action on the long actions.
Justin

Thanks Justin