870 Technical Question

[blood_donor]

How is the magazine tube on a Remington 870 (Express) attached to the receiver? Is it user-replaceable, or does it have to be soldered or something by a gunsmith?

 

[Banshee]

it is silver soldered in.

 

[dfariswheel]

The magazine tube is not a user replaceable part, and it's not a good idea to allow a local gunsmith to attempt it either.
It's brazed in place with a special high-temp brazing compound.

Since the tube absolutely MUST be perfectly aligned and positioned, replacement is considered to be a factory ONLY job.
If the new tube is misaligned even slightly, the barrel will not assemble to the receiver properly.

At the factory, the receiver is totally stripped of ALL parts, including the shell releases and the entire ejector assemble.
The old tube is removed by heating the receiver until it can be removed, and the receiver cleaned of all the old braze.
A special alignment jig is attached and used to align and position the new tube absolutely perfectly with the receiver, and the entire assembly is put in a special electric furnace to re-braze the new tube in place.

After brazing, the shell releases and ejector assembly are installed and the receiver is refinished.

Due to the near impossibility of getting the new tube perfectly aligned in the receiver without the special assembly jig, and the need to totally refinish the receiver, this is best sent in to Remington to insure a quality job.

They do a perfect job and usually at as good a price as any local 'smith will.

 

[Fred Fuller]

Thus the frequent reminders to those who add aftermarket magazine extensions to 870s to use a clamp to reinforce the extension. Damage to the threads on the magazine tube, or to the magazine tube itself, will require factory level repair...

lpl/nc

 

[blood_donor]

Lee: BINGO!

I added a 2 shot extension tube. I had to drill out the punched in tabs that kept the plastic end cap in place. The result is not pretty, but seems to work.

 

[Fred Fuller]

Drilling out the dimples is the best way to go IMHO as it gets rid of them completely. The holes are covered by the barrel ring, no big deal there, and there is no residual metal from the dimples left in the wrong place to cause feeding problems later as is often the case when some tries to 'iron' them out.

The clamp is a definite asset and should ALWAYS be used with any 2-shot or larger extension. It isn't to reinforce the extension but to keep a blow on the extension from exercising leverage sufficient to damage the magazine tube threads or the magazine itself.

Stay safe,

lpl/nc

 

[Simon Yu]

Quick question, what do you mean when you say magazine tube threads? Is it a part of the tube where it connects to the receiver, something inside the tube, etc.?

 

[Banshee]

the magazine threads are the ones under the little cap on the end that keep the barrel in place.