Remington mag extension misalignment

[ever0095]

Recently picked up a used 870P with a 2 shot Remington mag extension. Broke it down, cleaned, reassembled, and noticed that the extension clamp, when screwed on, would force the extension tube slightly downward. If I loosen that clamp slightly, the top of the clamp will not fully wrap around the barrel.

Feel like I'm missing something obvious here. Any ideas?

20150728_075306.jpg (84.86 KiB) Viewed 5725 times

[Synchronizor]

It looks like you have the wrong bracket. As I understand it, Remington makes different extension brackets for high-spaced and low-spaced barrels. Using a high bracket with a low barrel or vice versa will pull the extension tube out of alignment.

[ever0095]

That would make perfect sense. I've spend around 30 minutes just now looking for reference to differently sized clamps and haven't had any luck. Any idea on where to purchase? Also, if my barrel/mag extension is compatible with another brand of clamp that includes a light rail, even better.

Thanks for the help.

[knucklehead211]

That would make perfect sense. I've spend around 30 minutes just now looking for reference to differently sized clamps and haven't had any luck. Any idea on where to purchase? Also, if my barrel/mag extension is compatible with another brand of clamp that includes a light rail, even better.

Thanks for the help.

Almost all clamps work with the factory extension; that said, Mesa Tactical and CMD both make well received clamps that can also accommodate a light or rail.

[Banshee]

Remington sell two different clamps




it appears you need the "X" marked one.

From what I have been told the
“X” marked clamp for the rifle sight “Police” barrels.
Taller, unmarked clamp for the standard bead sight barrels.

[ever0095]

Thanks for the help guys. I've found the right version on Remington's part site. Just need to make a choice on going that route vs. a Mesa/CMD clamp with light mount.

[Synchronizor]

Keep in mind that many aftermarket clamps with rails have more tacti-cool side-mounted sling attachment points rather than a traditional bottom-mounted sling stud. Most factory 870 stocks only have a bottom sling attachment point, so you may have to buy additional hardware if attaching a sling is important to you.

[Hangernade]

I recently purchased a used 870p and I too have tube droop. What makes a different clamp needed? My son has an express with an extra barrel. Both of those measure the same outside diameter as my rifle sight barrel where the clamp makes contact. Is it the factory mag extension that is thicker then? Is it strictly the 870p's that have this issue?
If I just snug the screw lightly it makes the mag tube stay in line but the clamp is not properly seated on the barrel. I'm mainly concerned because I was looking at the S&J bayonet clamp. Will I have the same problem with this or any other mag clamp? Haven't decided if I'm going to do anything about a sling mount if i get the S&J clamp.
Haven't located those larger stamped steel bayonet mounts yet. Not sure if I'm really liking them but they do look strong, and have a built in sling mount.

[Synchronizor]

The issue isn't so much the diameter of the extension tube or the barrel (though there are some specialty light-contour and heavy-wall barrels that have nonstandard outer diameters), but the center-to-center spacing between the barrel and the magazine. Some barrels sit up a little higher than others, and therefore need a taller bracket to keep the extension aligned.

The S&J Hardware bayonet mounts are meant for lower-set standard-diameter barrels. I have a high-spaced Wingmaster barrel with the traditional adjustable Remington rifle sights, and if I pair it with a factory extension and the S&J bayonet mount clamp, the extension gets pulled up out of alignment slightly. If your extension gets pushed down when you use a tall bracket, like in the image in the original post, you probably don't have a high barrel, and the S&J bayonet mount should fit properly.

[Hangernade]

Outstanding. After my last post I researched that other bayonet mount. Turns out it's the m870 military one that is no longer produced and yeah, I'm not spending that kind of money for one.
My son says I should see if someone wants to trade a short clamp for my tall one but I think the odds are against finding someone interested in doing so.