View Full Version : how to add extension tube on 870p

April 20, 2011, 09:46 PM
I am trying to add a 2 round extension tube on my 870p, and this is what I have after remove the Magazine Cap Sling Swivel on the mag tube.

Anyone knows how to take out this thing without damage it.

Many thanks


T. O'Heir
April 20, 2011, 10:31 PM
Hi. That's just the mag spring retainer. Go here and look at the manual. Page 11 about putting in the mag plug. There may be a couple of 'dimples' that will have to come out too. Wee drill.

April 20, 2011, 11:20 PM
thanks T. O'Heir, I got the retainer out.
One more question, the wilson combat 2 round extension tube I got does not have a sling mount, do you know any sling mount that will fit it.
the extension tube I got is this one



April 21, 2011, 01:17 AM
If you have an 870P it won't have the dimples and I believe the spring retained in your photo is the type used on a P style 870. The dimples are found on most of the 870 Express mag tubes. The 870 magazine tubes with dimples have a different kind of spring retainer that engages the dimples of the mag tube. If you add a mag extensioin you won't be using the spring retainer. Some info on mag extensions is found on the AI&P Tactical site. http://www.aiptactical.com/How-To_Videos.html

April 21, 2011, 06:13 PM
An excellent sling mount and barrel clamp is a close copy of the excellent Remington factory clamp sold by Tank's Rifle Shop.
This clamp was actually made by Uncle Mike's but they no longer catalog it.

You want a clamp because if you drop of give the gun a good bump, the extension can break off the gun. That ruins the gun's magazine threads, and that's a trip back to Remington for a replacement.


For just a swivel, you can install a plate between the extension and the barrel support.
These are available with the sling mount on the right or left side, or the bottom:



April 21, 2011, 08:55 PM
thank you guys.

have a great weekend!!!

April 21, 2011, 10:32 PM
Well the other fellas beat me to helping out! You should post the pic of the final product.

April 21, 2011, 11:18 PM
Dfariswheel. I oftened wondered about the wisdom of mag extensions without barrel clamps. I usually don't use my Remington 2+ because removing and reinstalling the barrel clamp is a pain and I swap barrels several times a week for either going to the range or shooting drills, while I keep my only shotgun set up the rest of the time for HD with the short barrel. It's nice to know that clamp serves a purpose even if I don't attach a sling to it. Also, I had thought of just mounting the extension without the clamp and now I know better.