I have a 590 with an "accessory lug."

Which model bayonet accessory fits this shotgun?

Anything that will fit the M-16/AR15 will fit.  M-7 bayonet for example.

Supposedly, there was a flashlight from Mossberg that fit that lug but I haven't been able to locate it.

IMO someone should adapt the old 1895 (or longer) bayonet to the modern lug pattern for mounting specifically on the 590.  Make a real trench gun out of it.

Didnt someone post about the new marine bayo not fitting, it was like 1/8th inch too long?

But M-7s and M-9s shouldnt be a problem.

Quoted: Didnt someone post about the new marine bayo not fitting, it was like 1/8th inch too long? But M-7s and M-9s shouldnt be a problem.

Make sure you avoid the imported knock-off M-7 and M-9 bayonets. Some have noted that the specs are off on these and some do not fit. Besides, you're probably getting crappy steel to boot.

The Ontario USMC bayonet WILL NOT fit correctly, but there is an easy fix.

Add a front sling attachment that fits under the magazine cap and it will give you the extra length you need. I use the GG&G model and it adds the perfect amount of space. The ball detent will also keep your magazine cap from coming unscrewed.

Quoted: [ The Ontario USMC bayonet WILL NOT fit correctly, but there is an easy fix.

Thanks for the info.  Do you know which M9 bayo will fit the 590A1?  Is there another Ontario M9 besides the USMC version?

Quoted: Quoted: [ The Ontario USMC bayonet WILL NOT fit correctly, but there is an easy fix. Thanks for the info.  Do you know which M9 bayo will fit the 590A1?  Is there another Ontario M9 besides the USMC version?

The M9 is the Army bayonet, the M11 is the USMC bayonet. The M9 should fit, if from a quality mfg like Ontario, LanCay, etc.

There was a post about someone not being able to fit the ontario bayonet, but someone else posted a fix and it seemed to work. They had to push the mag cap out about 1/8". think it was a sling plate he added to make it fit. However my Lancay M9 bayonet fits fine. I have the M9-LW from ares EOD. I have not tried others to see about fitament.