So after several months my MCX started jamming with the same wad cutter pellets I'd been using. Then it started leaking CO2 out the receiver just like my 2 MPX's. To late now to get a refund. I called Sig and to my surprise they payed the shipping to send it back for repair
I got it back today and the repairs were... chamfered chamber feed ramp, replaced mag belt(pellets load much easier now) and replaced valve body assembly. So will see how long it holds up this time.