Mossberg 590a1 is a military issue pump action shotgun in use by the US military and various law enforcement agencies across the US. Despite the many versions with differing sights, finishes, stocks, and accessories offered, there are only two primary size/capacity versions available. The 20inch barrel version which features a 8rd magazine and the 18.5 inch barrel type with a 5 round magazine. The 20inch versions often feature a bayonet lug, while the 18.5 inch version's magazine is considerably shorter than the barrel making a bayonet attachment impossible. Shorter shotguns are easier to wield in close spaces. My 870 wears a 18.5 and a short stock and is only an inch over a yard long for that very reason! However, mine has a 6rd magazine tube that is virtually flush with the muzzle. Unfortunately, the design of the shorter 590a1 means that it is always limited to 5rds. No extension is possible. Also that eliminates something I'd also like on static defensive shotgun. 8inches of sharp steel. Good for a phalanx against goblins and rioting chavs during reload.
Mossberg. You make a very beloved shotgun. One that the infamous JayG loves for its stabbity goodness. However, I, and I'm certain lots of other people, would love to see a bayonet ready, 6rd magazine version of your 18.5 590a1. Guys, it would SELL. Remington would not be happy. I would not have an 870 right now. I'd have an 590a1.
Ontario USMC bayonets on it. 8inches of carbon steel stabbolicious.