Gentlemen,

I've recently purchased a Stoeger M3K and I would appreciate any feedback regarding essential mods to help it run the lighter 28gm loads reliably.  I plan on breaking in the shotgun with a slab of 34gm ammo, but ideally I would prefer to use 28gm rounds in competition.  All suggestions and guidance gratefully received.

28 gm = 1 oz. loads, right? 34 gm = 1 1/8 load. Don't think there are any mods to actually run lighter loads, but most of the guys I've read really break the gun in well. It should run 28 gm loads after a thorough break in. You might consider a Benelli extractor too. The Stoeger extractor seems to be a bit deficient.
 

There is one mod I remember now. You could polish the outside of the mag tube where the recoil spring rides.