> TEOTWAWKI Blog: Project 590A1: Tritium Bead Nightsight



Project 590A1: Tritium Bead Nightsight

View down the barrel after swapping in a night sight bead.

First up in our 590A1 upgrade series is some work on the sights, or perhaps more correctly, the sight, as the stock 590A1 ships with a plain jane bead front sight.

Bead sights on shotguns are fine and dandy, but when things get dark and chaotic, they can be tough to see. Sure, you might say "Bro, it's a shotgun--who needs to aim?". To which, I call BS. Yes, buckshot will spread, but only a few inches at home defense distances we'd be employing a shotgun in. Aim poorly and you can miss, and who is to say if you will get a second chance to hit.

So, aiming is important, and having every edge to help you get buckshot on target is smart. And that's why they invented night sights, which we're used to seeing on pistols but maybe not so much on shotguns. Replacing a stock bead with a tritium night sight is a simple, inexpensive project that takes only a few minutes to complete.

For a Mossberg like we're working on, the sight you want is the Meprolight Tru-Dot Night Sight, available from Amazon for under $35 ($32.88 at time of writing). If you've got a Remington 870, the process is the same but you'll need a different model night sight.

Install is simple.

Remove the factory bead sight. It is a hex base, and the Mossberg is reportedly a 5/32" size. I just used my Leatherman and went slowly and carefully to avoid marring the barrel - consider taping the area around the bead to provide some added protection.

To install the new sight, add some loc-tite to the threads of the night sight, and then screw it in. On some thinner-barreled Mossbergs like a stock Mossie 500, you may need to file off some of the bottom of the sight to get it to fit correctly. With my thick barreled 590A1, the Meprolight sight did not require any fitting, so your mileage will vary.
Side profile of the 590A1 after installing the tritium sight.

The last turn of the night sight may require some pliers. Be careful not to over tighten the sight...the threads are quite small and can be damaged them out if you keep tightening.

Obviously, you want the tritium facing you and centered up in the middle of the barrel.

Give it some time to let the loc-tite set and you're done.

The tritium tube is a huge help for aiming in low/no light situations - just put the glowing orb over the target and blammo. It's also easier for aiming in daylight too - the white dot is much easier to visually ID than the black bead sight. An all around improvement--definitely recommended. Enjoy!


  1. I just got these the other day for both of my Mossbergs (590 & 590A1) but my 590A1 has ghost ring sights so it was a different front sight than for the 590 which has the bead like yours. I haven't put them on yet but your post has inspited me to do so this weekend.

    Do you know if the bayonet lug can be added after the fact to the 590 or do you think it would be too weak since it doesn't have the heavy ported barrel like the A1 does?

    Thanks, and keep 'em coming!

    1. Many of the 590s ship with a bayonet lug and a heat shield, so I think it'd be plenty strong enough to have the lug. How to add the lug to a 590 that doesn't have one...that, I don't know.

  2. a touch of glow in the dark paint on one side of the existing bead is much cheaper!

  3. This is true, but will require ample charge time. Tritium vials offer the benefit of a high discharge glow, without any charge or drop off. For a scattergun left in the closet for HD, this can be a godsend.

  4. Would that work on a Maverick 88?

    1. I think so? Some Google-fu might help, but the 88 should be about identical to the 500...you can always return the bead to Amazon if the threads don't match up.

    2. Thanks!