My clamp keeps moving......

[kotengu]

I have a magazine/barrel clamp with sling swivel on my 870, and under heavy use it slides forward slightly. Not really noticible shot-to-shot, but after 75rds or so I can look down and see it's shifted forward about 3/4" or more.

Is there anything I can do to stop this, or should I just torque the sucker down and loc-tite the retaining nut? I'm a little gun-shy to try to torque things too much - I don't want to strip the clamp or damage the barrel/magazine extension.

[Devonai]

My solution was to place strips of electrical tape on the inside of the clamp, sticky side away from the barrel/tube. It created enough friction between the clamp, barrel, and tube to keep it in place. The tape needed to be replaced every once and a while, but it's fast and easy.

[HSMITH]

Blue Loc-Tite, or 609 Loc-Tite. The drift is history, and the "repair" temporary and 100% removable.

[9mmMike]

My factory extensions have a groove around them that the barrel clamp screw lays in. They never move. I run these on my 870's & 1100's and they get used a ton. What kind of extension do you have?
Mike

[kotengu]

Advanced Technologies, IIRC - I made sure to search out the metal (not plastic) extention, and I believe the clamp/sling swivel stud was made by them as well.

That's a good idea about the groove and screw - maybe I'll figure out something similar that I can do to mine......

[Badger Arms]

If it's only a 2-shot extention, just leave the barrel clamp off. I've got a 21" barrel and I feel better with the clamp on there. Wilson Combat makes a sling attachment that sandwiches between the mag extention and the barrel lug. That definitely WON'T jump forward when you shoot. It also won't wear the finish on your barrel. Only $10 at Brownells too!

http://www.brownells.com/aspx/NS/store/ProductDetail.aspx?p=12519

http://www.brownells.com/Images/Products/800100003.jpg

[Sgt]

Take the freakin' barrel clamp off you don't need it !!!!

[Dave McCracken]

Actually, Sarge, in the REAL world, barrel clamps have several advantages. The big one happens to be that clamping a thin shotgun barrel to another steel tube in effect both stiffens the barrel and makes the harmonics more consistent, thus aiding accuracy with slugs. Often group size is halved. And binding the front end together makes it stronger, and less likely to glitch when bumped.

Some people do buy the clamps for the Cool Factor, and shoot better serendipitiously. A happy accident...

[kotengu]

Sorry sarge - I'm an all "function" and forget about the "form" kind of guy, so the cool factor isn't even an issue. I got it for the reasons listed above, as well as providing a good sling swivel stud.

Can anyone post a couple pics of the factory extension and clamp, with a good view of the cross pin and detent?

I noticed the nut had backed off, so I cleaned everything up and loc-tited it all together, while torquing it to a fairly firm feel. Hopefully that will help - if not, I may be setting it up on the mill.......

[Sgt]

Well Dave,

In my world...let me check, I'm pretty sure it's real....uh...yep...still real ;) Whew!!

Some of this crud is just a waste of time and money....

But whatever looks cool....is obviously the way to go nowadays....

Hey, do they make them in Carbon Fiber?

[Badger Arms]

What function does the barrel clamp provide other than a sling swivel (which the Wilson product serves much better as)? On a 2-shot extender, the mag is only hanging 6 away from the end of the mag tube!

The big one happens to be that clamping a thin shotgun barrel to another steel tube in effect both stiffens the barrel and makes the harmonics more consistent, thus aiding accuracy with slugs.Okay, Dave, I'm gonna have to take issue with you on this one. If it makes groups smaller, what happens as it slips? What happens when you take the barrel clamp OFF as you have to do with it each time you wish to clean the gun? Why does this matter so much when most rifles (more accurate) have barrels that hang 24" or so beyond the front of the receiver when free-floated? A steel tube is tremendously strong and stiff. Clamping a loose clamp to hold two pieces of steel tubing together is unnecessary and I don't even think it looks any better.

The primary advantage of the Remington tube and clamp system, in addition to being recoil proof, is that you can remove the Remington barrel with its magazine tube still clamped to the barrel IIRC. The remington tube has a separate nut that screws on the the standard mag tube... again IIRC.

[Dave McCracken]

Badger, note the difference in thickness between shotgun barrels and even a light contour rifle barrel.

Dunno what happens when it slips, hasn't happened with the one Choate and one Remington extensions here. Both have that detent.

As for dismounting, I rezero as a matter of course. I can clean the thing properly without dismounting after general use, the stripdown and deep clean take place the day after deer season ends.

As to the reduction in groups size, try it and see what you come up with...

Sarge, do a little research in the Archives. I'm no fan of Cool, but run strong on pragmatics. This works, so I use it.

[9mmMike]

Another thing that I like about the clamps is that many of my barrels to not have the detent ball. The extensions w/clamp make sure that my barrels do not come loose. Even if the nut for the extension shakes loose, the clamp holds the extension, and barrel, in place.
It's sort of a visual aid to a loosening barrel. If the clamp stays put, then I know my barrel is not moving. Otherwise, I am constantly checking the mag cap.
Without the clamp, I have had the barrels shake loose. This has never been a problem on my older barrels with the detent ball though.
Mike

[Badger Arms]

Here's the only picture I could find of the Remington Mag extender.

http://www.remingtonle.com/images/access/magext_18b.jpg