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Posted: 7/14/2007 1:34:09 PM EDT
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Ok, I've searched the forum and web...only to find conflicting info. Do the gas rings need to be offset from each other or is it OK if they line up? Thanks for any clarification. Lex |
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You really don’t need to alternate them on a perfectly functioning AR. But throw into the works a possible reduction in gas flow or some other type of cycling problem, and you just might be looking at short cycle issues. Alternating the gas rings takes just seconds, and was engrained in me 22 years ago in the military.......so I still do it out of habit. ETA: photo 
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Your welcome. I added more info as well. Some here will tell you that they’ve run their rifle on ONE ring and the rifle functioned fine. I believe them and that’s a great test of the health of your rifles gas system. But........if your rings happen to be aligned and excessive gas escapes past them, along with say a loosening gas key or a gas tube on the verge of blockage or partial blockage, then you might be looking at short cycle problems. It’s so simple to stagger the gas rings during assembly….why should you not do it?! It’s simple insurance. Just my personal opinion. 
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| The gap in the rings is minimized as the bolt is inserted into the carrier and the rings are compressed. The Colt armorer class covers this, but I will have to admit that I was among those that tried running the gun with two, then just one ring. It ran fine, but I would never leave it that way. Nothing more than having fun, since it was not tested under harsh conditions with a high round count. If it makes you sleep better at night, take the 5 seconds to stagger them. |
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The whole thing is, on a perfectly running and well maintained weapon, gas ring alignment should not pose a problem. But, as I stated, if other factors come into play then you might run into problems. What I’m trying to explain is referred to in aviation maintenance as “The Swiss Cheese” effect. This idea can be applied to anything, but is mostly used to illustrate the sequence of events which lead up to an incident or accident. . You can have numerous conditions, which when occurring simultaneously end in a certain result. The slices of Swiss cheese represent each condition. When the situation permits that the “holes in the cheese” line up, then you get the end result. In my illustration below we have four conditions, that when combined with each other could lead to a short cycling rifle. Sure, each condition it self, if serious enough could result in a short cycling rifle. But, lets say each condition is not severe enough to cause a short cycle on it’s own, so none of the “holes in the cheese” line up. Now we throw into the mix, bolt gas rings which are aligned. Now our “holes in the cheese” have lined up. Now we have a short cycling rifle. Lining up the gas rings could have possibly avoided this situation. I hope this clears up how I personally perceive the importance of such a simple act as the couple seconds it takes to line up the rings. 
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What QUIB describes is called "tolerance stack up" in the engineering world. Complex engineered items like aircraft, cars and even weapons are designed around the various different parts operating together with a certain tolerance for each item. This + or - tolerance can stack up as QUIB describes in his "Swiss Cheese" analogy and failed or unwanted type operation can occur. Each individual item can be within it's own tolerance but coupled with the other items tolerances, can throw things out of wack. These tolerance stack up problems are sometimes the worse to troubleshoot and repair as any one item you pull out for measurement and/or bench check, can check out good. Hootbro |
TM 9-1005-319-23 Unit And Direct Support Maintenance Manual M16A2, M4, M4A1 |
The fit between the smaller round tail part of the bolt and the hole it fits in in the carier leaks a lot of gas. Key vents between the rings and the rear part. Notice the amount of carbon on the firing pin. |
Ok, I see what your saying. I guess that area is not critical to the function of the rifle. If it was I’m sure there would be some type of inspection criteria. |
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