Forward sling mount for 870 with XS mag tube extension?

[gato naranja]

FWIW, this is a big reason why I stick with Vang or Wilson tube extensions that include the sling mount. I don't like the ones that sandwich between the extension and the main tube, as it reduces the thread engagement of the extension.

If the tolerance stacking is running against some particular combination of mag tube, barrel, plate and magazine tube cap (or extension), it really can result in alarmingly meagre thread engagement.

Back when I still wanted to run a sling plate on an 870 that required no tools or extra time to take down, I cut my potential losses by running a Wilson +1 extension with the integral plate... whether I wanted the extra round or not. If I couldn't find a REM extension with a factory clamp today, I would go back to a Wilson or Vang extension with an integral plate. Those mag tube threads make me nervous as a cat in a room full of rocking chairs.

[Dorsai]

I've got this on my 870.

https://www.gggaz.com/remington-870-...tachments.html

[Pnut]

If the tolerance stacking is running against some particular combination of mag tube, barrel, plate and magazine tube cap (or extension), it really can result in alarmingly meagre thread engagement.

Back when I still wanted to run a sling plate on an 870 that required no tools or extra time to take down, I cut my potential losses by running a Wilson +1 extension with the integral plate... whether I wanted the extra round or not. If I couldn't find a REM extension with a factory clamp today, I would go back to a Wilson or Vang extension with an integral plate. Those mag tube threads make me nervous as a cat in a room full of rocking chairs.

I run a GGG sling plate on my setup and never ran into problems. With the plate in place, you’ll only lose maybe 1/2 to 3/4 of a rotation on the end cap/extension tube.

[gato naranja]

I run a GGG sling plate on my setup and never ran into problems. With the plate in place, you’ll only lose maybe 1/2 to 3/4 of a rotation on the end cap/extension tube.

I had no problems with sandwiched plates on most of the 870's I have owned or used, but that particular problem would arise because either a mag tube was shorter than "spec" or a barrel had the magazine ring located too far forward. Shouldn't happen, but it did. When it gets down to only one thread's worth of engagement with the magazine cap or extension, that is - IMHO - cutting things too fine to justify a sandwiched plate.

[gato naranja]

This is a "thing" with some 870 parts. Sometimes it seems like tolerance stacking, but not always. The aftermarket clamps are the most frequent bad actors, but I have even seen some factory extension tube and clamp combinations that do what you describe, and they flat-out bent the tube down too far. In one case, Remington wanted the problematic one back to look at and then sent me a replacement that was good to go. The tubes and the barrel bore axis should be more-or-less parallel.

UPDATE:

I went back through the shotgun annex of my box full 'o' crap and found a notation to myself to use the factory clamps that have an "X" stamped on one side; this must date to the time I returned a clamp to Remington and they sent me a new one. I think the general idea was that clamps without an X are for 870's with older, less thick barrels, while the ones stamped with an X are for MOST of the modern 870's.

So if you have an issue with a factory clamp not fitting your particular mag tube/barrel combo, look for the presence or absence of the X. As for aftermarket clamps, "caveat emptor."