The 930 that he rates as #3 is one that I heartily agree with. I bought one five or six years ago, on the recommendation of a relative who's a (literally) world-class shotgun guy. He owns a bunch of crazy-expensive shotguns, but his home defense shotgun was a 930, and based on his praise of it I picked one up, and been extremely happy with it. I doubt I'll ever 'want' a shotgun as my primary long arm, but if I had to use a shotgun it would be the 930. Had it over eight years now and the only load I've tried in it that it won't run with is a load that specifically warns against trying to use in autoloaders; a reduced-recoil #8 birdshot load at less than 1000 fps. Every other load I've tried in it from 2 3/4 birdshot to the 3-inch "black magic magnum" slugs have run flawlessly.

Basically, the 930SPX is my favorite item in a non-favorite category.

 

I ran a Mossberg M500 ATP6SP for over 20 years and was very happy with it, until I upgraded to a M590A1, then I became happier with my choice.

 

Box o truth did some interesting testing with a variety of weapons, including shotguns. They built a series of residential walls and proceeded to shoot them with different guns and loads etc.

9mm, buck shot, .45 all had extreme overpentration. .223 had the least - the bullets tend to fragment at those ranges and while they would go through the dry wall, by the time they went through both sides of the wall, they were so badly fragmented that they would not penetrate another set of walls. The idea being that inside a house, you aren't going to be killing your neighbors by shooting a bad guy or missing a bad guy.

with typical handgun, shotgun, or other rifle rounds, your neighbors aren't going to be too happy with you, even if you get the bad guy.

Birdshot didn't over penetrate too badly, but it is probably the least effective - not that it won't work, just that it isn't the best choice.

 

I only briefly carried a shotgun for serious purposes, an older Mossberg 500 in the late 90's that was the only shotgun I had at the time. It was a pretty vanilla gun with a five-shot tube and a six-round sidesaddle on it. Rural arkansas LE, and largely due to overpenetration concerns I carried it with #4 buck loaded in the tube, and three each magnum 00 Buck & magnum sabot slugs in the sidesaddle. That was only for a couple years (and never used it), until they finally okayed carbines for patrol use. At which point I immediately switched to the CAR-15.

 

Based on my shooting experience with shotguns, I see only 7 1/2 shot, #4 shot, #4 Buck and slugs are needed to fulfill the basic hunting and defensive requirements. If you have additional storage facilities or a larger discretionary income you may choose to add additional stock.