I think it best that before getting into this too far the intended purpose of this new 12 gauge is clearly defined.

A couple things I would point out are that if you are looking to go rifled barrel slug gun you are going to spend alot of extra money if you go away from an 870 or 500. No 2 ways about that.

IMO the new 870 or 500 you might buy today aren't a heck of alot different and either will serve you well for years.

The old (older) Wingmasters are a different matter.

Something else to consider is what the US military chose after the extensive evals they do before purchasing. They chose Mossberg.

Not saying one is better than another when it comes to the 870 v 500 issue because IMO it is a toss up.