The Stoeger M3000 is a great shotgun for 3 gun. It's an inertia driven (not gas driven) shotgun. This means it runs cleaner than a gas driven shotgun, such as the JM Pro 930, which can suffer from fouling if not maintained properly. The manufacturer suggested price is $600, but the street price can be as low as $450 with rebates. It's a good shotgun for multi-gun, but there's been a lack of aftermarket parts specifically for the M3000.
There are aftermarket parts such as Nordic Components extension tube for Benelli shotguns that fit the M3000. Tactical Bay did a series of videos show how to modify Taran Tactical Benelli components to fit the M3000. Jesse Tischauser also shot a video on how to open the loading port. All the videos seem to involve a bit of filing to get the parts to fit correctly.
The lack of bolt-on aftermarket parts and accessories is changing. MOA Precision is manufacturing and selling parts made just for the Stoeger M3000. I've ordered the charging handle, oversized safety and follower to try them out.
Carbon Arms is also selling their VersaTube for the M3000. The Versatube is a complete stainless steel replacement for the tube which eliminates the need for an extension and possibly polishing to improve performance. It comes with a carbon fiber shroud to reduce weight. The website mentions that a less expensive aluminum version is in the works.
I'll write about installing and testing the MOA precision components when they arrive.