870 Express mag tube loading issue

[GunnerGSP]

OK. I have a Rem 870 Express with factory +2 extension. I should be able to go 6+1 but loading the 6th shell into the tube is a nightmare.

After the 5th, inserting the 6th is a crap shoot. Sometimes it will insert with no issue, other times I jam away at it and eventually it will give in and load. Unfortunately, my thumb is pressing with some force and when the 6th shell finally gives way and goes in, my thumb follows quickly behind jamming into the mag tube. Man, that hurts!

Factory spring and follower are installed.

Any ideas what I can do to remedy?

[Synchronizor]

This is usually due to the first shell catching on a gap where the magazine tube ends and the extension tube begins. The Remington extensions mate the tubes together with a coupling nut, but if the tubes aren't butted together inside the nut, there will be a gap there. A common reason for this is pinching a coil of the magazine spring between the tubes during installation. The coil will come loose when the magazine is loaded, but the gap will remain. If you're not using a clamp, or if the clamp is too loose, the extension tube can also come loose on its own as the gun is cycled and fired.

Try taking the extension tube clamp off, removing the extension tube, then make sure the coupling nut is tightened down firmly. Then, screw the extension tube about 3/4 of the way on, and load the magazine with 6 shells (you may need to fiddle with the still-loose extension tube to get the stack of shells past the gap). Once the tube is loaded, screw the extension tube down the rest of the way and snug it up firmly. Then re-install the clamp to keep the extension tube from backing off.

By loading the magazine before tightening the extension tube down, the spring will be completely inside the extension tube, where it can't get pinched and cause a gap. Test the magazine now, and see if that fixed the problem.

Professional 870 builder J.D. McGuire has a video on YouTube where he talks about and demonstrates proper installation of a Remington extension. He addresses proper coupling and how to avoid snagging the spring, though his method is a little different than mine.

[GunnerGSP]

You know, I tried JD's method 3 or 4 times before I read your reply. I think I may have finally got it.

However, I do like your method as well and if what I did so far does not help, I will definitely try it.

Thanks...