Is there something up with this front bead sight?

[SixPointEight]

The bead on my 30 + year old 18.5 inch 500 barrel is an identical base to the on in the OP's photo. Clearly threaded in and dressed to the bore. A replacement bead may well need to be dressed. A bead removed from another gun may work well, but pay very close attention to the bore once the bead is installed.

Only really matters if you shoot slugs. I lost a couple of beads, and sent my barrel back to mossberg. Once they put in a bead that didn't extend a hair into the bore, the problem went away.

[BigDogatPlay]

Only really matters if you shoot slugs.

Okay.

A bore obstruction is a bore obstruction. No firearm is safe to shoot with something in the bore that shouldn't be there, but that's just the way I feel about it.

[yelohamr]

The bead front sight fell off of my Mossberg 25 years ago. I don't miss it, but I recently added a heat shield with ghost rings.

[SixPointEight]

A choke is a bore obstruction.

If your bead is in the barrel a couple mm, it will be forcefully removed with slugs. Everything else will shoot fine. Ask me how I know. I sent my barrel to mossberg twice before I got it back without a little of the bead sticking into the barrel. THAT was when I quit losing beads while shooting slugs. My barrel is fine, my gun is fine, I am fine. A slight intrusion by the bead isn't what I would call a bore obstruction.

[BigDogatPlay]

Probably be good to add YMMV. But your experience is yours. I always prefer to err on the side of safety.

[rudeboy3]

I have a 18 inch vented rib on my 870 with nothing on top and I shoot it much better than my ghost ringed Mossberg

[Peter W Bush]

I find that I shoot MUCH better when I ignore the fact that my shotgun has a bead. When you are used to your shotgun and have a proper mount, the gun will hit what you're looking at. I love shotguns

[inbox485]

Need some Mossberg guys to jump in on the OP's last post with install advice cuase I tink the stem is going to come down into the bore and needs to be filed down. Is this correct Mossberg guys.

If the above is correct then it may not be a Range install.

The threading is through the wall. If you install a new bead, you need to verify that it does not protrude. AFAIK, the replacement beads are pre-filed so that they are drop in ready, but a protrusion would FUBAR your patterns or worse so it would be wise to check. Unload the gun and take the barrel off the gun before messing with the sight or looking down the barrel.

I would recommend just switching the sight out. The sight picture you are supposed to have with a bead is a fuzzy flat line (the flat top of the receiver), a brass ball in hard focus (just the ball - which is the part your broken sight is missing - and not the rest of the pedestal), and a fuzzy target in the background. If you are missing the ball, you are missing the only part of that piece you should be seeing when you are using it.

As far as hitting 100 yard (man sized) targets with slugs off a bead, that is very doable if you can get somebody to teach you long gun fundamentals. The one time I tried, I was hitting clays resting on a berm at that range about 1 in 5 shots once I had a feel for the drop.