I recently purchased a Choate 2+ mag extension tube for my 870, but the thing won't work on my 870.  The problem is, Remington replaced the older spring-retaining compression clip with a notched piece of plastic, which slots in to the two notches and holds the spring in place.  These notches are pressed in from the outside of the magazine tube, which creates the two notches inside the magazine tube.  Unfortunately, these two notches block the rim of the shells inside the tube.  Is there any way to press these back out without damaging the mag tube, or will I simply have to Dremel the damn things off (which will subsequently leave two small holes in my mag tube).  What should I do?

Simple answer and what I did, drill them out, deburr it and splash some cold blue on the holes. No harm, no foul. You will waste mucho time screwing with a Drimel, IMO.

yep

Bingo!  Metal-appropriate drill bit large enough to remove the indentations.  I've done this on all of my later-production 870s with no ill effects (except that if you go back to the original magazine end-cap you will have to hold the plastic spring-retainer in place under spring-tension until you start threading on the cap - it won't stay there by itself anymore, no biggie).  [:)]

I’ve never done it myself, but I understand some folks simply drill them out.

Brownells sells a magazine tube dent remover (basically a mandrel) that I’d think would do it; but it goes for $50.

You might want to contact Choate for suggestions – I suspect they encounter this question constantly.

Edited to add that, as usual, all sorts of folks here type faster than I do!!  [:D]

I used a dremmel and it worked perfect.

Don't sweat it, no big deal.  I drilled mine out too.  I picked a drill bit at or slightly under 1/4" I think.  Basically, I just picked one that fit in the slot.  After drilling, I had some small pieces of the bumps left on either edge of the hole and I simply filed them down with a curved files.

It's not even close to a high-stress area, and even if it was, those round holes probably wouldn't matter much.  The barrel-band will also cover them when the gun is assembled so you will never see them.

Now, the issue you will have to worry about is the spring and detent that were used to keep the cap from unscrewing during firing (yes, it WILL come unscrewed during firing, had it happen to me).  That's what they used to use, newer models used the notches on that plastic goober to do the same thing.  Now that your bumps are gone and you are using an extension (that is also set up for the old detent and spring) you will need to get the detent and spring.  My barrel on my HD model had the hole for them and I merely dropped the spring into the hole followed by the detent.  I have been meaning to get to a smith to have them permanently fixed into there, but until then I am just carefull when dissasembling.  You could also get a mag-tube clamp to hold it in place.  Amazingly, brownells doesn't carry the detent...at least not when I checked last about a year ago.  I ordered the spring and detent directly from remington.

-G

drill it out on each end.
polish with some 400grit and cold blue.

DING!DING!DING!DING!......WE HAVE A WINNER!!!!

I did it a few years back using a deep well socket that just fit in the end and slowly tapped it in and it basically forced the indents out.  No holes that way.

I've done 3 with a Dremel and they never went all the way through.

Drill the holes, you won't see them under the foregrip.

Just be sure to deburr the inside.

Whole project shouldn't take more than 10 minutes.

Edit to add:

Since my original reply, I just hammered out the dimples in my newest 870 using a 17mm Craftsmen socket, followed by a larger 11/16 Easco socket...(Perfect fit)
The Craftsmen 11/16 socket is too big.

Hehe...[LOLabove]

Took me all of 13 minutes start to finish. [:D]

my gunsmith used the dent tool on my tube. now it is perfect.

Thanks for all the info!  So, how difficult it is to hammer out the dimples?  Does it take a lot of force?  Thanks!

Jason