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Posted: 4/5/2015 9:20:06 PM EDT
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A bit of backstory and Disclaimer.
I did not build my AR and although I know the basics of its functionality dont talk as though im a seasoned veteran, Thanks. I bought my AR a while back and after having some problems with double feeding and rounds failing to fire, I had one round that fired but also blew off a part of my BCG. After a ton of cleaning and check over the rifle and installing a new BCG I took it out to see if it all works good. It fires great, feels like it always had as well. It doesnt seem to double feed anymore either. Now it seems that after every 5-6 rounds I get one that stovepipes. It does fire, opens the bolt all the way, grabs and chambers a new round, but the spent casing kept getting stuck on its way out. I dont have a picture but hope im explaining it pretty well. Any help or ideas would be great, I love shooting my AR but if this keeps up i may have to get rid of it. Thanks. |
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Also does the bolt lock back on the bolt catch (catch in front of the bolt face, and not just on the bottom of the carrier) after the last round is fired from the mag.
When you pull the charging handle all the way back, does the face of the bolt retract back past the last edge of the ejection port window, or does the face of the bolt stop around 1/8" to 1/4" in front of the back of ejection port window edge. Also when you are pulling the charging handle all the way back, does the last inch'ish of the pull seem harder than the rest of the pull? |
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I haven't seen many problems with ejector springs, but I have seen problems caused on other people's ARs by bad extractors, extractor springs, and missing extractor spring inserts.
Sometimes the lip on the extractor that slips over the cartridge rim is not formed properly. This can cause the extractor to fail to grip and pull the case from the gun's chamber. The extractor spring insert (black is he new color, the older blue ones work fine too) is supposed to be located inside the extractor spring (current extractor springs are gold, the older ones were black, they both work fine). It help the extractor to clamp onto the cartridge rim by applying tension to the extractor's lip, helping it hold onto the cartridge and extract it from the chamber after firing. A defective extractor, or a defective extractor spring can cause extraction problems and leave the spent cartridge casing anywhere in the gun, and may look like a double feed, when it's really a casing extractor failure. If you have spares, I'd recommend trying to replace the extractor, extractor spring, and the extractor spring insert. If not, it's time to order a field or critical parts spare parts kit. |
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Quoted:
Also does the bolt lock back on the bolt catch (catch in front of the bolt face, and not just on the bottom of the carrier) after the last round is fired from the mag. When you pull the charging handle all the way back, does the face of the bolt retract back past the last edge of the ejection port window, or does the face of the bolt stop around 1/8" to 1/4" in front of the back of ejection port window edge. Also when you are pulling the charging handle all the way back, does the last inch'ish of the pull seem harder than the rest of the pull? It does lock back with the catch in front of the bolt face after the last round. When the charging handle is pulled it retracts all except about 1/4" of the bolt past the ejection window. The last bit does not feel hard at all, very smooth pull. This Whole BCG is brand new only bout 50 rounds on it, could it be sticking as part of a break in period? |
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Ejector/extractor issues then,
Pull the B/C, hook a spent case on the extractor and cam the ejector into the bolt face channel a few times to make sure that the ejector is under a great deal of spring tension, but it is not binding in it's travel in the bolt channel. If the extractor is binding, then it will need to be pulled (side roll pin)/ the channel and extractor cleaned, then the extractor reinstalled with the roll pin (use a spent case to hold the extractor in place while you drive the roll pin back through the relief slot of the extractor for the roll pin. Next, remove the extractor, and check the very bottom side edges on the grabbing claw for burs. Also, just below the claw, check the ends of the rim relief channel for milling burs. If found remove the burs, but do not dull the grabbing claw edge. Lastly on the extractor, go to a hardware store, pick up a $60 O ring (about a dime) and before you put the extractor O ring around the extractor spring and install the extractor back in the bolt. This will add some tension to the extractor, and in cases where the chamber is slightly on the new rougher side, will make sure that the spent case is not dropped by the extractor on chamber pull (until the chamber self polishes out through live fire and cleaning). The O ring should last around 500 rounds before CLP does it in, and at that time that the O ring is falling apart, if the O ring is still needed, then replace the extractor spring with a M-4 type extractor tension extractor spring (do not use a O ring with an extra tension extractor spring). 
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check out my thread on the matter
http://www.ar15.com/forums/t_3_66/668480_Poor_extraction_with_5_56_but_not__223___WHY___.html it was solved by changing out the spring on the extractor. it was quite worn out. |
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check out my thread on the matter
http://www.ar15.com/forums/t_3_66/668480_Poor_extraction_with_5_56_but_not__223___WHY___.html it was solved by changing out the spring on the extractor. it was quite worn out. |
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On a new rig, would dare to guess new chamber on the rougher side, and the chamber will self polish out threw live fire and cleaning, and the O ring/extra tension Extractor spring will not be needed in a few hundred rounds.
In the mean time, the spent case is a touch harder than normal for the extractor to pull the spent case that is still pressure welded to the chamber walls at extraction under bore residual pressure, and would dare to guess that the extractor loosing grip of the spent case rim now (case not still on the bolt face to the end of stroke, to be pivoted off the bolt face at the back of stroke). Also to add, you do not use a extra tension extractor spring, and a O ring/Defender at the same time!!!!! The extractor still has to climb over the case rim at loading, and if the tension is too much on the extractor, then the extractor will not climb over the rim, but instead just failure for the bolt to fully lock up reliably instead. |
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