I just cleaned my MP153, what a GREAT gun! It's a toss up if I am going to use it or my Kel-Tec KSG for turkeys this year... KSG is likely going to win to scare the fudds, ha ha. Just need my choke adapter to show up & I am off to the races!
Cheers
Jay
P.S. WRT getting the gun to reliably shoot light loads, I believe you MUST follow the break in procedure as per the manual & then try the lighter loads. If it won't cycle them after 100 rounds of heavy loads, shoot another 100 rounds of heavy loads, clean well & then try the light loads again.