UPDATE:
Shot the new gun for the 1st time this morning. I wanted to run some ammo through it to break it in prior to hunting with it, and also to pattern test it and see if the Carlson steel shot choke tube I got for it likes the same ammo my Mossberg 935 does, but just didn't get around to it. So, it was a baptism by fire so to speak as I hit the marsh for some waterfowling this AM. Things went great!
Despite not doing the recommended 100 round break in I had ZERO cycle issues. This things cycles as smooth as hot butter. Really like how it shoots. I also took the time to install the recoil reducer that came with it( heavy metal cylinder that goes in the stock and screws on to the stock bolt ). I read that the M3500 without the RR kicks like a mule. Well, I felt it kicked less than my 935 by quite a bit. Instead of a hard slam as with the 935 it was more of a firm push. Much less annoying so I am glad I installed it.
The best news is I shoot awesome with it. The gun fits me perfectly and the shot goes where the gun is pointed. I only had 5 chances today as there was no wind and it warmed up quite a bit. Birds just didn't move a lot.
First chance of the day was a drake Black/Mallard hybrid that fluttered in over the dekes shortly after shooting time. 1 shot and 1 bird. Good start. A while latter a Bufflehead buzzed the dekes and another shot and another bird. So 2 for 2 and both were head shots no less.
After that a flock of GW Teal surprised me and landed next to my boat blind. I screwed up getting the safety off as they flushed so by the time I could shoot they were at max range and I missed as they flared away. As I was reloading from that 3 other GW Teal came past the dekes and I rose, picked a drake, and fired = another downed bird with 1 shot and another head shot.
Last chance of the day was a flock of Gadwalls that worked the edges of the spread but didn't want to commit. I finally decided they weren't going to get closer and rose to shoot. The darn safety got me again and they were really out there by the time I could shoot so like the 1st flock of Teal I missed.( NOTE - I am not talking about skybusting here - max range but doable - have made similar shots countless times with my other guns ).
So when I didn't screw up the safety I was 3 for 3 with 3 head shots. You can't do better than that. I do believe had I not messed up with the safety I would have limited out taking 3 birds out of those 2 chances. But?
I am VERY HAPPY with this gun. Works great and shoots where you point it. My only gripe is the safety location. I am used to it being on top at the back of the receiver after decades of shooting Mossberg's. I have to get used to it being down by the trigger now. I greatly prefer the Mossberg location.
All in all I was happy as was my Lab, Sadie who got to do some work...