View Full Version : mag extensions

01-31-2004, 08:00 AM
Has anyone had problems with binding springs when using plus two mag extensions? I have had good luck with the vang plus two extension on my 18" barrel 870, except that the spring has softened quickly. I am going to try a replacement spring from wilson combat. I had a problem with the mag spring binding up in a different 870 (Rem Express HD, 18" barrel, 6-round mag tube). I bought it from Big 5 with a factory plus two mag extension already installed. I have already replaced the follower with a vang hi-viz follower, but have still experienced the binding spring problem. I have noticed that the spring that came with the Express HD is much longer and slightly narrower in diameter than the spring that came with the vang extension. I am wondering if the narrower spring and/or the factory mag extension is causing the problem. I just ordered a plus two extension from wilson combat, which comes with their extra power mag spring. Hopefully this will solve the problem. Any advice?

Lee P. Lapin
02-04-2004, 08:14 PM
Both the Vang and Wilson extensions you mention are quality items. I can't think why you would have problems with magazine springs that were related to the extension itself in either one of those, unless it was a QC problem from the factory. The factory Remington extension, I dunno- no experience with that one. And a 7 round extension is pretty conservative compared to what some people hang out there (what IS it with some people, some kinda John Holmes complex or something?)

Now some diagnostic questions:

Do you keep your magazine fully loaded, all the time?

Is your 870 an Express version which had the dimples swaged in the magazine tube?

Has the inside of your magazine tube been cleaned and oh so lightly lubed? How about the spring itself? The follower?

Kinked magazine springs are the big bugaboo for tubular magazines, but proper care and maintenance (and not 'crunching' the spring by loading the magazine completely full and trying to stuff in one more round, or loading full and leaving it) should prevent most of such problems. Think of a magazine extension as some _potential_ space instead of loading it full. I always leave one space open in a tubular shotgun magazine, both to 'relax' the spring a bit and to leave a space open for loading different ammo than what is in the magazine if needed for the first round up the spout.

I have used Choate extension kits (7- and 8-shot) for decades now with no problems. I have used several Tac-Star 7-round extensions on the 18" barrelled guns I have put together lately as well, with no problems so far.

Inspect the inside of your magazine tube closely, and experiment with different followers and springs as you are planning. If you stil have problems, bring it back up here.

Good luck, and Stay Safe,


02-04-2004, 09:29 PM
Lee's right if yours has the dimples, they need to be pressed out to function right, we got some a couple of years ago that had slipped thru QC, and once the dimples were pressed out they worked fine

02-05-2004, 10:01 AM
Thanks for the replies. My 870 express doesn't have the dimples, so that wasn't the problem. I just installed the wilson +2 extension with the wilson replacement spring. This seems to have solved the problem. I think part of the problem was that the factory spring is slightly narrower than the wilson and vang springs. I did notice that the wilson spring is longer than the vang, resulting in a more powerful spring tension. I keep my 870's loaded to full capacity(6 in the tube, empty chamber). I know this will probably accelerate spring wear, but I plan to replace the spring every several months anyway. I'm not sure if the factory extension was part of the problem, but I did away with it just to be sure. I now have a vang extension with wilson spring and wilson follower on one 870 and a wilson extension with wilson spring and wilson follower on the other 870. I've noticed that the wilson follower is slightly longer than the vang follower, and seems to slide a little smoother in the mag tube. I've inspected inside the mag tube and it's clean. I think the problem is solved, but I'll have to put both shotguns through their paces at the range to be sure. Thanks again for the feedback.