MPX receiver fit???

[MHitchcock]

Handled one today, just curious if a bit of play between the receivers is normal for these. All of my AR's are rock solid and it just seemed odd to me.  

[SergioSF]

My MPX also has this play. There's a tension adjustment screw in the lower to help, but that takedown pin is also so tough to move, that I just ignore the play. 

 

[ccshooting]

As mentioned, there is a tension adjustment screw.  You have to remove the grip to access it.  That screw has a spring loaded contact point that meets the take-down lug.  I have found that the best point of adjustment is as far as you can take it without taking out off of the spring load in it.   Yes, it will be difficult to push out the take-down pin with this amount of tension, but since it is spring loaded, you can press the upper and lower together to make pushing out the take-down pin much easier.  I use a plastic chamber flag in my MPX.  It also works well as a take-down pin punch, which helps too.  Put some blue loctite on the adjustment screw to keep it where you want it.