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Discussion Starter · #1 ·
Took out my new 18" wilson combat barrel to the range today and had a few issues with it. First issue was it short stroking. It has a rifle length gas system. Im using a carbine buffer and carbine spring with 36 coils. Gas block is properly aligned. Use the dimple on the barrel to align it. Tried a few different bolts and carries and had same issue. The other issue was its causing a bulge on the case webbing. This is the first time I've ever had this happen on my reloads. Tried different ammo and brass through it and it did it to ever brand of brass from new unfired starline brass to resised Hornaday brass. I had a few different loads worked up ranging from 90 grain tnt's to 130 spear BT. Same issuse on everything I tried. Short stroking and bulging. I emailed Wilson Combat today about it. Probably hear back on Monday from them im sure. I was just wondering what would cuase the case bulging? Oversized chamber? too much headspace? All these loads run fine in my other barrels, Noveske and Yankee Hill barrel. Any input would be helpful! thanks
65759

65760
 

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I’d bet on an out of spec chamber on this one. Years ago I had a Japanese Arisaka that stretched brass like that, and I sold it to a collector with full disclosure.
 

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You can check the headspace by depriming the fired brass, measuring the case base to shoulder and comparing to unfired cases.

Why would an 18" have a rifle gas system?
 

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The bulging cases can cause the rifle to short stroke. There are few issues that can cause bulge cases. Other signs of overpressure on your handloads would be the first thing to check. Try lowering the powder charge or firing a couple factory loads. It could be a headspace issue. It is possible there is some blockage in the gas port or the block not being aligned.

The bulge can easily be caused by an improperly machined chamber or tight bore. It is difficult to tell from your pictures, is the bulge concentric to the case? Does it bulge evenly or to one side? If a case bulges to one side it will, effectively, wedged itself in the chamber and require more effort to eject it.

I am very curious to see how this works out for you. Please keep us updated. My wife's new Savage in 270 Win has the same issue. We just got the gun back from Savage this week. In typical Savage form, we have had no communication from Savage on what, if anything, was done.
 

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Discussion Starter · #6 ·
You can check the headspace by depriming the fired brass, measuring the case base to shoulder and comparing to unfired cases.

Why would an 18" have a rifle gas system?
Good question on the gas system. I guess you'd have to ask Wilson Combat about why they made it rifle length. I have a feeling the gas port is too small for that length. I tried a few different powders including h335 being the slowest, hoping the slower burning powder would cycle the rifle. It didn't make any difference other then blowing a huge flame ball out the muzzle.
 

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Discussion Starter · #7 ·
Update: I got a hold of a headspace gage today. When i insert it into the chamber it rattles around side to side. I think I found the problem here. The chamber must be cut too large.
 

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Good question on the gas system. I guess you'd have to ask Wilson Combat about why they made it rifle length. I have a feeling the gas port is too small for that length. I tried a few different powders including h335 being the slowest, hoping the slower burning powder would cycle the rifle. It didn't make any difference other then blowing a huge flame ball out the muzzle.
I wonder about the rifle length system also. My WC 18" barrel also came with rifle length gas system. I had to open the gas port two drill sizes, to .094" The bolt would not lock back before I enlarged it. FWIW, Wilson does not make their AR barrels. I think they come from Bartlein.
 

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first see if a round chamber and then extracts easily by hand. I had a grendel doing about the same. What i found out was i actualy had an overly tight chamber and when the bolt was sending the rounds home it would chamber them just enough to fine but not a 100 percent. The short stoking i thought i was having was because it took so much to extract them from the chamber that there wasnt enough gas left to complete the job. What cured it was just setting my press up to cam over harder on the shell plate. I mean hard enough that things on the bench jump. Might not be your problem but its easy to check. Just load about 5 rounds in your mag and run them by hand.
 

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Update: I got a hold of a headspace gage today. When i insert it into the chamber it rattles around side to side. I think I found the problem here. The chamber must be cut too large.
Adam Savage voice: "Well, there's your problem!"

I'd definitely take pics and/or video and e-mail them to WC. I hope this is a one-off issue, and not a broader problem. Other folks who don't know what to look for (and, therefore, would just crank on the gas block and keep running it) could end up getting seriously injured.
 

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headspace guages check head space. Not chamber dimentions. There made to drop in and close a bolt over.
 

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Wilson gas ports being undersized is pretty common, you can check it with a 3/32 drill bit. It should be interesting to see what they say about case bulges.
 

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Did you ever measure the difference between a fired case and an unfired case as suggested?

Sent from my moto g(7) play using Tapatalk
 

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Old school way of checking if you had a sloppy chamber and didnt have a set of calipers was to size a case. Dont prime it charge it or seat a bullet. Then drop in in your chamber and take a wooden down and give it a good tap with a hammer. If you tilt your barrel up and it falls out its on the loose side. But thats a crude test. I dont care how hard you pound on a head space guage its going to fall out. Its made to easily drop in because its not made to measure for loose chambers. It made to check the dimension to the shoulder. You can have a head space issue on the tightest chamber or a sloppy one.
 

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If you have a micrometer, measure the diameter of your case web. I can compare it to measurements from my rifles which I keep track. Include the brass manufacturer. Calipers can work too, just not as accurate.
 
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Discussion Starter · #20 ·
After talking with Wilson combat they had me send the barrel back for replacement. Well see it they say anything about it when the get it. I'm convinced theres a problem with the chamber. I understand the gas port being too small but I've never had case bulging issues like this before in the maybe 10 different 6.8 barrels I've owned. I used that headspace gauge on a few other barrels I have and it didn't rattle around at all like it did in the Wilson barrel. To be more specific about the rattle, what i mean is it would fall to one side like the chamber was out of round. That would explain to me the case bulge on just one side of the brass.
 
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