Home Forums Hunting & Shooting Hunter's Campfire Specific sight adjustment question

I recently acquired a Mossberg MVP Scout in 308. It has a long Picatinny rail on top, with a ghost-ring sight built into the very back of it. There’s an aluminum front sight screwed into the barrel that looks very, very fixed to me.

The rear sight slides side to side in a channel, and it’s held in a particular position by a couple of set screws, one on each side, tightened against each other.

But I can’t figure out how to adjust it for elevation. The owner’s manual is no help. I thought for a bit that I could loosen one of the windage screws and then screw the sight ring up or down by twisting it around its vertical axis, but although the sight ring and the base appear to be different pieces, they seem to be permanently fastened together somehow.

The gun’s accuracy seems okay, but it prints eight inches low at 25yd.

This is my first real ghost-ring sight. Anyone have any ideas? Thanks.

Buy a lower front sight or file it down.
8 inches low at that range is extreme.
Or shim the bottom of the rear.


Call mossberg and find out what ammo and what distance they regulate it too.
( goodluck with that)
Its gonna be the biggest mystery of the day for em until you get thru to the right person.

Wow!
8" @ 25yds
Probably 2' low at 100 yds
Yup, Call Mossberg.

Looks like a Williams fiber optic sight in the pictures, no? So you're out of luck filing it down. Wouldn't mess with the rail, your primary sight goes there. But I too would e-mail Mossburg first.

Not much info out their in Google fu land either about those sights.

People seem to.replace em with aftermarket ones. Front and rear.

Couldnt find a thing on how to adjust for elevation.


I would be calling mossberg and play phone fugg with them until ya get the answer about how to get that rifle hitting better.

Good luck.

Thanks for the advice.

Sounds to me like a sight picture/hold issue.

Barak, forgot to say if it is Williams one piece they do make them in several heights.

But that is one mean adjustment. Figuring the sight radius at 23.5 inches ( that's a guess) it's .209 inches.

If it was me I'd bench it at 100 yards to get a better picture of what it does. Then go from there.

From what I'm reading you loosen ONE windage screw and turn the sight. 1/2 turn equals 1.25" at 100 yards.

Try loosening the rear sight windage screws and see if the rear sight turns (threaded) to raise it.

I'm betting it's turned all the way down right now.

Looked up the MVP Scout and found this picture.



The aperture is obviously meant to screw up and down for elevation. If it won't turn with the windage screws loosened then I would assume it's just stuck somehow. Maybe some penetrating oil like Kroil, Liquid Wrench or such could loosen it. Looks like those threads go all the way around the stem so it could be that someone really cranked down on the windage screws and damaged the aperture threads, that would make it very hard to turn.

But bottom line is that yes, it is supposed to turn up and down.

That does indeed look like the rear sight I have, and the post does look threaded when I peer at it from the bottom of the detached rail, and it’s easy to see that the side set screws have been turned in far enough to damage the threads; but the ring does not twist around the vertical axis at all, and I’ve torqued on it hard enough to be scared of shearing it off.

Now, I haven’t tried the penetrating oil, because it doesn’t look corroded; but I’ll do that.

Some dummy might have used Loctite on the rear sight threads. If the rear sight is metal, slide it out of the rail and heat it gently with a Propane torch. Even red Loctite turns loose at around 500 degrees, and that's not enough to hurt metal, even aluminum.
Jerry

Yup, that was it. I squirted it with WD-40, then loosened the set screws, put an appropriately-sized steel punch through the ring, and torqued it back and forth. After about three swings with no movement, it broke free and started turning under protest.

Maybe it was Loctite Red. Weird, though: it's a brand-new rifle, straight from Mossberg.

In other news, in case you're interested, I like it a lot except for a few things.

First, it doesn't have a third sling stud. I understand that Ching slings are expensive and Mossberg doesn't want to include one for free, but a Scout rifle without a third sling stud doesn't make sense.

Second, it's got a bull barrel. Haven't figured out why. Scout rifles are supposed to be light. This one's under seven pounds, barely, but it seems they could probably turn another half pound off the barrel.

Third, it comes with short rails bolted to the left and right of the stock up front. Lasers and flashlights and whatnot, I imagine. But a Scout rifle should not be contaminated with heavy, bulky extra crap: it's supposed to be light and handy.

Fourth, and this is a small one, I wish it had a three-position safety. Two is okay-I-guess, but I do like to be able to lock the bolt down. On the plus side, the safety is precisely where it should be for a right-handed shooter.

But there are plenty of things I like about it too. Short, handy, perfect cheek weld when thrown to the shoulder, trigger and bolt throw about as good as can reasonably be expected on a commercial-grade rifle. I put a nice Leupold FX-11 Scout (2.5x, 28mm) with low quick-release rings on it, and it's very nice too.

Anyway, it turns out that the WD-40 was indeed the special sauce. Thanks, Jim in Idaho, Hotrod_Lincoln, and Dave_in_WV.

Okay, that’s why it’s got a bull barrel. With 10- or 20rd box magazines, it can get really really hot surprisingly fast. My theory is that a thick barrel provides stiffness and thermal mass.

Still heavy, though.

Barak, you can use a high wattage soldering iron to break Loctite loose without harm to a rifle. You need to heat about 2 min. and then try to break the bond. Sometimes a bit longer.