Second range day:
So...it didn't go very well.
What did I do in an attempt to remedy any spring issues? Left the slide locked back for a good 60 hrs. I also cycled the slide the slide fully back a good 500 times.
Got to the range and put another 150 rds through it. 100 was 124gr American Eagle and the rest, 50, was 115gr Federal Champ. The good news was the accuracy was still great. The bad news was the ejection was just as bad. I didn't see any improvement in the ejection at all. It didn't seem to make any difference which ammo I shot. A lot of brass off the forehead. The casings that didn't hit me just barely cleared my right shoulder. It was really a bummer. I tried the same ammo through my XDm and HK that I had with me, no issues whatsoever. I sadly think this is destined for a trip back to S&W.
Know the status of your weapon
Keep your muzzle oriented so that no one will be hurt if the firearm discharges
Keep your finger off the trigger until you have an adequate sight picture
Maintain situational awareness