[mrskeet410]

By gas chamber I mean the cylinder under the barrel with the gas ports and into which fits the rings and magazine tube. I don't know the real name. I've always heard it call the 'gas chamber' and will use that term here. I hope you can figure out what I'm talking about.

I have and 1100 with two barrels. One always functions. The other frequently malfunction with light loads that work the other. Gas ports open. Gas chamber clean. Same size gas ports, and two in each barrel.

In the barrel that works, the chamber is a smooth as a baby's bottom. There are machining marks in the barrel that malfunctions.

If I get my gunsmith to polish out the machining marks, will that just make it worse because there is now more room between the rings and the gas chamber? Thoughts?

 

[Brian in Oregon]

First, "gas chamber" is the official name Remington gives to what we'd otherwise call a barrel hanger, especially on a pump gun.

In the photo above, The gas chamber is a horrible rusted mess. I carefully polished it, but it was impossible to get rid of dozens of pits without opening the diameter up to the point where the rings would no longer be of sufficient size to seal. Even with all of these pits, the gun now cycles OK. The point here is as long as the traveling surface for the rings are smooth, you need not worry about machine marks UNLESS they were in the same direction as ring travel, which could cause a gas leak IF they are deep enough.

If the problem continues, there may be other problems:

A misaligned gas chamber:

A misaligned slot of the barrel tang (which engages a locating stud in the receiver to index the barrel);

Failure to properly seal with the o-ring at the back of the gas chamber. One way you can sometimes cure this is to place the o-ring further out on the mag tube and let the gas chamber push it into place, instead of placing it in the groove on the mag tube. If this works, reassemble that way every time. Some have found they can cram two o-rings in there;

It may be that if all else fails the gas ports may have to be carefully opened up with step drills, testing as each incremental size is used. My gut feeling is that this is going to be the real issue. Remington barrels work well based on average loads. They get iffy for consistency with very light loads. I have some field barrels that cycle light loads, and identical twins that will not. Most of these are lighter than what Remington officially says the guns will cycle.

 

[Paladin]

Very informative, Brian.


One of the best Rem semi-auto posts in years.

 

[superxjeff]

Cgheck and make sure that your action spring is not binding. If it has never been replaced that could be part of teh problem. So many things it could be. My last ditch effort when all else has failed involves using a drill bit. Those holes are tough to undrill when you find out that it's not the ports. I have seen them plugged with a tiny screw before but that is a big pain as well. make sure your magazine tube is well cleaned and don't be afrid of a few drops of rem-oil on the action bars and a few on the magazine tube. Good luck! Jeff

 

[halfmile]

Take note of the gas ring construction. The upper ring is beveled on the bottom and fits into the lower which has a matching bevel.

When the gun is fired the upper bevel forces the lower ring to expand.

You would have to have an awful large diameter to lose sealing with this system.

HM

 

[mrskeet410]

Halfmile - Take note of the gas ring construction. The upper ring is beveled on the bottom and fits into the lower which has a matching bevel.

When the gun is fired the upper bevel forces the lower ring to expand.

You would have to have an awful large diameter to lose sealing with this system.

HM

I never thought of that. Good point.

 

[mrskeet410]

SuperXjeff - "I have some field barrels that cycle light loads, and identical twins that will not."

That's what I have as well. Ports are open on both, and the same size.

 

[halfmile]

Skeet, I have like at least a dozen 1100 barrels. If I encounter a problem I get out the number drills.

They are like women, no 2 alike.

HM