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Discussion Starter · #1 ·
I'm the guy who posted about the stove pipe jams in a new XCR a couple days ago. I was told that firing it another 220 rounds should cure the problem. I'm preparing to do that tomorrow and was giving it a very thorough cleaning tonight. All the parts slide very smothly, so I'm a little dubious that shooting it more will fix it, but I'll give it a try. Before I go out and shoot $100 worth of ammo hoping to fix the problem, I have a couple questions about the fit of a couple parts on my XCR. The owner's manual says the problem I'm having can be caused by the gas setting too low. I have mine on 4 and these things could cause low gas pressure. I can't find anything in the manual to answer these questions and don't have access to another XCR to look at, so I'm hoping someone here can answer these questions.

Is the gas valve supposed to be really loose in the gas block? Mine wiggles around easily (about 1/16") while held in place with the detent, and if it is moved to the position where it can be removed it will fall right out. It certainly is not making a tight seal in the opening. Is this normal? My only other experience with rifles that have a gas valve similar to this are an Aug and an MSAR STG-556. With either of those the valve fits rather tight even when clean and requires a pull to get it out after moving it to the removal position. My concern here is that gas is leaking out around the valve to the point that it is reducing the force on the piston. There is a groove around the gas valve about 1/8" in from the flange that holds it in place. Is there supposed to be a seal of some kind in that grove, or do the gas valves just fit really loose?

Is this normal for the gas tube to have a little bit of back and forth movement? I suspect it is, because the gas block is seated all the way against the shoulder on the barrel and is tight, but I've seen a new Springfield M1A that wouldn't cycle at all because the part similar to the gas block was not properly aligned with the hole in the barrel at the factory. That was easy to fix.

One other question that is just a curiosity. What is the "Barrel Extension?" There are references in the manual to cleaning it and inspecting it, but it is not shown in the disassembled view in the manual and I don't see anything I would call an extension on the barrel.

Thanks for any answers to these questions.
 

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Yes, the gas valve is a little loose, that is normal. It fits a little loose but it works. I have had both gas blocks and the new one is way better than the old one that never moved (except with a wrench).

Again, it sounds like your gas tube is normal.

I believe the part refered to as the Barrel Extension is the fairly large part on the chamber end that slides into the upper reciever. It looks to be press fitted to the barrel.

I know you don't want to go out and waste a bunch of ammo, Make sure you have a couple good quality mags, you would be amazed how many failures are due to mags. Pick up a few of the P-mags, at $15 each you really can't go wrong. The only stove-piping I have had on mine was when I tried to turn the gas setting down too soon.

I am sure you will get it all worked out...
 

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No reason to be "wasting" that ammo... would you be shooting it any differently if you were not getting some stovepipes? Whatever you were planning to do with that ammo, I'm sure you can still do it. Just, maybe, with the occasional stove pipe.

Your gas valve sounds normal. Can't comment about your gas tube; I've yet to remove mine.

To clean the barrel extension and make sure it is free of debris, you will neet some Qtips. They are talking about the enlarged round area between the chamber opening and the locking lugs on the upper. I.e., the area where the locking lugs on the bolt rotate in the receiver. You're probably fine there, as excessive debris in that area would just keep it from going all the way into battery.

The only other thing I have not seen you comment much on is lube. *You need lube. Lots of it.* I use Breakfree CLP.

After 300 rounds are through the gun, you can see areas where parts have worn into each other. These areas need to be lubed, I would presume, especially during break in. Get some Breakfree or Remoil, or whatever your favorite is, and put lots of it on the bolt/carrier, inside and outside, for the remainder of the break in. Good luck...
 

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The only other thing I have not seen you comment much on is lube. *You need lube. Lots of it.*
Well said, Lube is essential during breakin. Everyone has a favorite, mine is Militec1. Whatever lube you use, just make sure you use plenty of it. Just when you think it is lubed, add a little more. As the parts wear together you will need less and less.
 

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Discussion Starter · #5 ·
Thanks for the answers. Sounds like my gas plug is fine. As for the lube, I had cleaned it and applied a lot of CLP before shooting it the first 80 rounds. In fact, I was sort of surprised at how much was in there when I took it apart last night. I've got a bottle of Militec1 and will thoroughly lube it with that this morning when I put it back together. I've also got a variety of mags to try today. A couple of the stainless steel C-Products and a couple of new Colts, one with the green follower and one I put a Magpul follower and spring in, and the one that came with it.
 

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Yes, don't worry too much about the valve. If your valve was bad, you would experiencing things like the rifle not cycling at all or almost 100% failures to eject.
Bad gas valves are NOT fun. :-\
 

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If the oil is dripping out the bottom of the lower it might be overlubed - maybe. I was using cheap ammo for my break in period and had some initial problems like you described but lots of lube and a few hundred more rounds made it perfect.
 

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Discussion Starter · #8 ·
Not dripping out the bottom, but a little was seeping out the sides where the upper and lower meet. I was hoping to get out and try it again today but something came up. Tomorrow for sure.
 

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You can be generous with the lube but DO NOT lube the chamber. If you do make sure it is very lite and not WET as you will cause fired casings to stick in the chamber or general extraction problems.

MadDog
 

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Discussion Starter · #10 ·
Thanks for the advice. I've been shooting for many years and know better than to lube the chamber on anything, but I can see how some folks might make that mistake. Took the XCR out to try it again today after a thorough cleaning and lubing it wth Militec1 this time. No improvement. The last mag of 20 rounds of American Eagle (rounds 300-320 through the rifle)got the same stovepipe jam half way through that I got with the first mag full when it was new. If they were becoming less frequent with usage, I'd keep at it, but 320 rounds made no difference at all. The dealer where I bought it was near the range, so I left it there and he's sending it back to Robinson, so I wouldn't have to deal with finding a cardboard box to put over the hard case it came in. Hopefully when it gets back it will work as good as the early XCR that I had and foolishly sold last year. It was 100% from day one.
 

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Discussion Starter · #13 ·
Thanks, Terra! I'm sure there's no need to say this, but please take as much time as required to make sure it's right. I'd rather have it working 100% than to get it back quicker. I don't tend to buy cheap ammo, but for what it's worth my old XCR on setting 3 with a total of 300 or 400 rounds through it would even function 100% with some they were selling at the range that wouldn't cycle my FS2000 reliably. It was a well known American made brand, but just weak. I'm hoping this one will be like that when I get it back.
 

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The problem with a lot of cheaper ammo is that manufacturers cut costs. One batch of Wolf and Silver Bear 9mm 115FMJ ammo failed to go beyond 1000 fps, while Fiochi was pushing 1200fps. Same thing with rifle ammo. Also by using cheap bullets the grouping sucked.

The adjustable gas system on the XCR should allow you to adapt to this however, and Terra will get it fixed for you.
 

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Just wanted to say... for the record... You didn't do anything wrong. It's something on the rifle, and I will definitely fix it.

I don't want any of you boys to think we blame you for the issues that come up from time to time. We had a production guy that let a lot of things slide. He's gone, and the guys working out there now are very, very nitpicky.

If your rifle works perfectly... I did it. ;) lol... j/k. I do help with a lot of the production and assembly, though, in all seriousness. ;D
 
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