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Posted: 11/17/2012 8:24:52 AM EDT
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Rifle: PSA upper w/M4 feed ramps. Spikes lower.
Owner: Novice to ARs Fail to feed ammo. This issue cropped up during my last two range outings. Pull charge handle and drop the bolt and the round only partially chambers. Pull the mag and it will fall out and have two dents in the case. Next round usually chambers but I will get this issue during firing about every 10 rounds. It doesn't matter if the magazine is full or near the last round. I have put about 1500 rounds through the rifle prior to this with no issues. When this 1st started I assumed improper lube since I used 30wt motor oil after my last cleaning session. After the next cleaning I used RemOil with no difference in performance. I have disassembled the bolt after every outing but I have only flushed the extractor with brake clean or BoreBright, no disassembly. I usually flush the gas tube as well or use compressed air. I have been shooting with a CMMG .22LR conversion kit. I always run a mag of 223 when I am done with the .22. It gets the rifle filthy inside so I always try to do a thorough cleaning when done http://i95.photobucket.com/albums/l148/supercobrajet/BE49AFA7-6781-4625-8115-1CA1AD00C787-234-000000154833A767.jpg Factory PMC XTAC 556 Tried 3 different mags, two Magpul 30 round and one Tapco 30 round. Upper and lower seem to be properly engaged, tiny bit of play. I am going to the range next week with some other plinking ammo and the rest of my XTac. I will try to borrow my buddy's GI steel magazine. I plan to take notes and see what happens Other than this, what can I look for to troubleshoot? It seems to me to be an ammo issue but this thing should eat anything I throw at it right? |
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Edited since the post contained no useful information, especially in the case of a new member how may not have yet grown the thick skin often needed on the site regarding off humor.
In the future, remember that poking one with a stick as an opening response statement is allowed (if done in light colorful humor), so long as it just your opening line, and then you get down to solutions to the problem in the rest of your post as well. Cheers, Dano |
| OP - FTFeed issues are generally mag related. Your mags a considered good, at least the Pmags. Inspect the mags and try in a different gun also. The 30wt motor oil should be GTG but are you lubing the right places? Are you lubing the bolt after you take brake cleaner to it? Inspect the feed ramps for any changes? Are you scrubbing down the the chamber and feed ramps with solvent after use? |
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Rem oil should be fine, but will find that BreakfreeCLP (spray can form) has a tad more cleaning agent in it, and less exspensive when you are comparing it to a 16oz of BreakfreeCLP as less than $10 a can.
As for the bolt over feed problems on initial feed, it steaming from one of two problems. 1. The mag is not being retained high enough in the mag well, and here, all you need to do is confirm that the threaded part of the bolt catch is flush with the face of the bolt release button. If with the catch set correctly against the mag release button, you find that the mag still has a lot of front to back rock, then take the catch one more thread inward, threaded part of the catch one thread proud of the face of the button. Note: if you are using the mag for a grab point during the charge, could just be you that are canting the back of the mag downward, and allowing the needed distance of the bolt to over run the rim of the top round in the mag. 2. The mag is either spring failing, or just fouled packed with so much debris, that it can not get the top round completely to the top of the mag for a clean bolt strip (rims side of the round sitting low, and when the bolt come forward to strip the round, rim is below the bolt line, so the but just grabs the top round via the middle of the case instead to try to force it out that way). Solution here, just pull the mag apart and CLP clean it. Also before putting the mag back in service, load a few rounds in the mag, shove the rim side of top round downward, and allow it to snap back up under it own power. The top round should snap back up to seat completly against the bottom of the feed lip. |
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Quoted:
Rifle: PSA upper w/M4 feed ramps. Spikes lower. Owner: Novice to ARs Fail to feed ammo. This issue cropped up during my last two range outings. Pull charge handle and drop the bolt and the round only partially chambers. Pull the mag and it will fall out and have two dents in the case. Next round usually chambers but I will get this issue during firing about every 10 rounds. It doesn't matter if the magazine is full or near the last round. I have put about 1500 rounds through the rifle prior to this with no issues. When this 1st started I assumed improper lube since I used 30wt motor oil after my last cleaning session. After the next cleaning I used RemOil with no difference in performance. I have disassembled the bolt after every outing but I have only flushed the extractor with brake clean or BoreBright, no disassembly. I usually flush the gas tube as well or use compressed air. I have been shooting with a CMMG .22LR conversion kit. I always run a mag of 223 when I am done with the .22. It gets the rifle filthy inside so I always try to do a thorough cleaning when done http://i95.photobucket.com/albums/l148/supercobrajet/BE49AFA7-6781-4625-8115-1CA1AD00C787-234-000000154833A767.jpg Factory PMC XTAC 556 Tried 3 different mags, two Magpul 30 round and one Tapco 30 round. Upper and lower seem to be properly engaged, tiny bit of play. I am going to the range next week with some other plinking ammo and the rest of my XTac. I will try to borrow my buddy's GI steel magazine. I plan to take notes and see what happens Other than this, what can I look for to troubleshoot? It seems to me to be an ammo issue but this thing should eat anything I throw at it right? It looks like you may need to replace the buffer spring. |
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Quoted:
It looks like you may need to replace the buffer spring. ??????? What does the recoil spring have to do with the bolt passing over the back end of the rim end of the round in the mag? Am I missing something, and we are talking about a recoil spring that is too long to begin, and needs to be replaced with shorter spring? The way that I read the ops problem, its just the first round being hand cycled into play that he is having the problem, and not the following feeds as the rifle is self cycling. |
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Quoted:
Quoted:
It looks like you may need to replace the buffer spring. ??????? What does the recoil spring have to do with the bolt passing over the back end of the rim end of the round in the mag? Am I missing something, and we are talking about a recoil spring that is too long to begin, and needs to be replaced with shorter spring? The way that I read the ops problem, its just the first round being hand cycled into play that he is having the problem, and not the following feeds as the rifle is self cycling. HAHA...Hi Dano. I accidentally posted that answer on the wrong thread, even on the wrong site. Had three different sites open at the same time.....Anyways, after reading about the OP's issue, it looks like the damaged cases are gouging against the sharp edges of the ramps. He said it happens 2 - 3 times per mag. He has 1500 rounds through it. The issue only recently started. I'd say either a mag-related issue (possibly dirty mag) or a slight possibility of a batch of ammo that has a few bad rounds of soft brass mixed in. |
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Quoted: Quoted: Quoted: It looks like you may need to replace the buffer spring. ??????? What does the recoil spring have to do with the bolt passing over the back end of the rim end of the round in the mag? Am I missing something, and we are talking about a recoil spring that is too long to begin, and needs to be replaced with shorter spring? The way that I read the ops problem, its just the first round being hand cycled into play that he is having the problem, and not the following feeds as the rifle is self cycling. HAHA...Hi Dano. I accidentally posted that answer on the wrong thread, even on the wrong site. Had three different sites open at the same time.....Anyways, after reading about the OP's issue, it looks like the damaged cases are gouging against the sharp edges of the ramps. He said it happens 2 - 3 times per mag. He has 1500 rounds through it. The issue only recently started. I'd say either a mag-related issue (possibly dirty mag) or a slight possibility of a batch of ammo that has a few bad rounds of soft brass mixed in. I don't see feed ramp gouges, I see gouges from two lugs of the bolt head after the round is picked up by the carrier instead of the bolt. |
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Not the carrier, but the bolt lugs themselves.
The problem is is that either the bolt is not getting behind the rim of the top round on the way back, or the top round is not high enough for the bolt to get behind the rim to push it forward out of the mag correctly, with either of the problems, the bolt stripping the top round out of the mag via the middle section of the case, not from behind the rim. The tip of the round get shoved into the barrel extension, then the bolt comes to rest on top of the middle of the round to cause the two indents. So we are back to square one, and the if its a first round hand charging the round in problem, then mag all the way, being either not getting the top round all the way up in the mag, or the mag not high enough in the mag well to begin with. If this is happening during live fire strings when the rifle is self feeding, the it still the same as the above, but we had to determine if the rifle is full stroking to begin with (and correctly lubed and cleaned so it does choke out on it own fouling during the shooting strings). So let take it from the top to determine if the rifle is first full stroking. Clean an lube the rifle correctly (we have a whole forum here to cover that, so go to it if you have question on how to correctly clean and lube the rifle. Now load only a single round into a mag, charge the round while leaving the empty mag in the rifle, and fire for effect. The correct effect if the rifle is full stroking will be the spent case ejected about 10' to 15' out of the port, and the bolt locked back on the empty mag. To take it a step farther, that 10' to 15' ejection distances should be for all rounds, and if you find that at some point in the shooting session, the spent casings are starting to dribble out instead, then the rifle is due for a re-cleaning and lubing. Now if we determine that the rifle is full stroking correctly to begin with, then we can move onto seeing if the problem is either a mag that is not recovering quick enough to get the top round back upwards before the bolt charges back forward, or as stating from the beginning, a mag that is not sitting high enough in the well instead. |
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THANKS GUYS!!!
I'll print these posts out and take them to the range this week. I will report back and close the info loop on this one. As for the 1st reply. don't worry. I am an AR noob but not a forum noob. I can take the heat but I ido appreciate the troubleshooting assistance from you guys. |
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Quoted: THANKS GUYS!!! I'll print these posts out and take them to the range this week. I will report back and close the info loop on this one. As for the 1st reply. don't worry. I am an AR noob but not a forum noob. I can take the heat but I ido appreciate the troubleshooting assistance from you guys. Any update on this buddy? If you haven't been to the range yet, hit me up. |
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