View Full Version : 870 Magazine Extension Issue

05-17-2012, 8:43 AM
A quick search didn't produce anything informative, so here goes:

I recently purchased a TacStar 2-shot extension for my Remington 870. It looked like a decent piece of equipment, but seems to have a serious design flaw. With the magazine cap removed, there is about 8mm of threaded magazine tube protruding past the barrel-mounting-flange-thing. But the inside of the magazine extension has about 20mm of threading before the diameter decreases to match the inside of the main magazine tube. This means that when installed, there is a roughly 1cm gap between the two inner surfaces where the inner diameter is larger and threaded, with a sharp ledge that is catching the magazine follower, rendering the entire extension completely useless.

Am I missing something? The 870 is at least 20 years old and doesn't have the retention dimples of the newer versions. Did Remington extend the magazine tube at some point? Does anybody make one that will function properly with my older 870? Help! And thanks.

05-17-2012, 10:20 AM
Your 870 is the same as the new 870's except for the mag dimples. All accessories fit them all.

Try this for help, I'm not familiar with the TacStar. Mine are Wilson:


ETA: Be careful if at work. This guy (like a lot of other morons) think in-your-face music at the beginning is a good idea.

05-17-2012, 10:28 AM
Also not familiar with this problem. I use Wilson / Scattergun or Remington OEM. Mag length on the older gun is the same as the mag length now.

From the OP's description the threaded collar on the is longer / larger than the threaded end of the mag tube?

Also... make sure your barrel is fully seated. There should be more than 8mm of threading out past the barrel lug.

05-18-2012, 7:19 AM
The barrel is fully seated, and I've installed/reinstalled several times, watched the above video, and several others. The follower still hangs up at the transition every time. Here's a picture of the end of the magazine tube with the barrel full seated:


OK, that didn't work. Maybe a URL:


8mm of tube to engage with the retaining cap (which really isn't more than 9mm deep) or the TacStar extension tube, which has about 13mm of threading, leaving about a 5mm gap which is causing the problem. How much threading does the Wilson Combat extension tube have?

05-18-2012, 7:39 AM
Are you anywhere close to Sacramento?

05-18-2012, 9:01 AM
Nope, Los Angeles.