870 mag extension (interior) coating

**rayh059** · May 3rd, 2011, 09:45 AM

I installed a magazine extension on my 870 express. As you know doing this requires grinding off the 'nubs' on the inside of the tube.

I did learn that if they aren't finished smooth, the orange follower plug can hang and cause problems feeding.

Now that its nice and smooth and feeding well, what should i use to finish the exposed metal? Right now I have a coating of rem oil.

**son of the revolution** · May 3rd, 2011, 11:16 AM

Originally Posted by rayh059

I installed a magazine extension on my 870 express. As you know doing this requires grinding off the 'nubs' on the inside of the tube.

I did learn that if they aren't finished smooth, the orange follower plug can hang and cause problems feeding.

Now that its nice and smooth and feeding well, what should i use to finish the exposed metal? Right now I have a coating of rem oil.

If it was me I'd probably just fog it lightly with some flat black spray paint. Your obviously going to need to make sure you get all the residue from the oil completely off if you want the paint to stick.

**JayBell** · May 3rd, 2011, 03:07 PM

if it wa me, and I did this recently, its better to leave it unfinished and use a light oil.

even better would have been to have swaged or pressed the dimples out with the appropriate size socket or round bar, and a small hammer.

use the hammer to punch the socket into the tube, knocking the dimples flat into the tube wall, then tapping many times lightly with the hammer to make the dimples part of the round tube again.

simple, and does not destroy the finish, nor does it fill your gun with metal bits and abrasives

**rayh059** · May 3rd, 2011, 03:19 PM

I did pull a rag up from the breach just short of the grinding spot before I started, then pulled it completely out (in that same direction), careful not to pull pieces down toward the breach.

I could see the pounding out method may be better. Next time.

**allglock** · May 4th, 2011, 10:21 PM

They do make a tool for it..... But I forget where I saw it.... Sorry.

**gold cup abuser** · May 5th, 2011, 05:57 PM

Brownells does make the tool to press out the dimples without damaging the finish, but for a one time only job it is kinda pricey. I recall that tool being in the 60 dollar range.....

Get the oil out of there and get some cold bluing compound and apply it with some q-tips. Hit it a few times and you should be good to go.