I recently acquired a Mossy 500 with 20 inch barrel.

8 shot tube.

Now I wonder if the 18.5" is better. It's only 6 shots.

Which makes a better HD shotgun -- 20" or 18.5"?

Or is this a 6 of one half dozen of another issue?

I have the 18.5 model 500 and like it a lot for HD. My house has short hallways, small rooms, and sharp turns so I will take the shortest I can get.
I do wish they would make a 6+1 model 500 with magazine tube the same length as the barrel. I have seen custom 500's like this.
If I lived in a more rural area, bigger house, or perhaps higher crime area, then I would say the 20 inch with 7+1.
Of course the best option is to buy a Maverick 88 in 18.5 inch and one in 20 inch and would only run about $400.

Also I forgot to say that the 20" is a 7 rd tube, not 8 rd. The 590 is 8 rd tube though.

Personally I prefer the extra shots with extended magazine and the 20 inch barrel. I don't think the extra length has much to do with the handling any and some states such as Michigan have overall length restrictions.
I have an Ithaca model 37 police shotgun with a 20 inch barrel and extended mag with a pistol grip. It just makes the overall length restriction and with an 18 inch barrel would have to be registered as a handgun.
There also is less chance a 20 inch barrel might be considered too short by a LEO with no ruler.

I have a 500 12 with the 8 round tube. Having nine shots on hand precludes the hanging on of various shell holders all over the gun. I appreciate that and really did not care about the difference between 18 ½ or 20. I have a dislike of stuff hanging off my guns. I feel it’s unwieldy and I believe in the KISS principle. I do have a bandolier hanging next to the Mossie with more rounds. The longer barrel is not a detriment to getting around in my house. I insist on full length butt stocks as the pistol grip only gun is a very hard to control and IMHO is best used in a movie.


In a SHTF situation whether it be man or beast I felt I was well armed and able to handle it with this gun. Gun is loaded to first fire 5 00 buck with 4 slugs to follow. I live out a ways in the boonies and my problems could be large marauding or rabies infected animals and this gun will do both humans and bears if necessary. Help if able to call could eclipse 20 minutes or more.

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14 S&W Revs none with locks!

As far as mobility, I don't think the 1.5" difference has any practical impact.

Swing might be affected having extra weight up front (barrel, tube and rounds), but it's leavened by the virtue of increased ammunition.

No way to know without direct comparison, but all told I think it's six of one, half a dozen of the other -- in a shoot you probably won't notice the length or weight differences of either, and are unlikely to need all the rounds either can hold.

I think you've got a fine set-up as is, and the money you might spend on a new barrel or entire shotgun is better spent on ammo, range time determining which defense rounds perform to you and your 500's liking, and a good defense shotgun class.

Witch the 5 rd tube 18.5 inch barrel, you can swap barrels easily for 24 or 26 inch, etc. With the 7 round magazine (not 8 rounds) you are pretty much stuck with the 20 inch cylinder bore barrel.

Both are good choices.

I went with the 18.5, but only because it was available and at a price I wanted to pay. It does fit better on the backwoods backpack too.

I wanted the 590A1 with 9 rds and bayonet lug. Why a bayonet on a shotgun ??? I can't figure it out, BUT I want one.

Mas Ayoob wrote a book called "Stress Fire" and covers techniques for defending you and your weapon against assailants. Not a bad read, honestly.