I just got a preban ar15, colt match hbar lower, the upper doesn't have any markings so I'm not sure what it is. The problems I am having are the bolt doesn't stay open when the mag is empty, that's annoying but no big deal, the main problem I am having is when I put the mag in and hit the bolt release it doesn't push the round into the chamber it gets stuck. This only happens on the first round of every mag, it cycles fine when its shooting. one last thing, last time I was shooting it one cycle felt rough so I popped the mag out and the top round had a dent in it about an 1/8th of an inch deep and a little over a half of an inch long, this only happened once. can any one tell me what would be causing these issues. Any input would be greatly appreciated.
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Problems with my ar15
- Thread starter vin
- Start date
First are you shooting handloads or factory ammo? I'd say strip it down and give the rifle a through cleaning,bore,chamber the works. i'm no authority on ARs but the first thing that come to mind is check the bolt face and make sure that there is no crud under the extractor. The second thing I'd try is a new recoil spring. Yvor mags may need an overhaul as well. Do you know anyone with an AR that might let you try the rifle with their mags? As i said I'm no Ar expert but these thing would be the top of my check list.
Clean the gun and try overhauling your mags also make sure your not over stuffing your mags. My money would be on the mag
What type mags are you using? GI,Thermold,Orlite? 20 or 30 rd? If you decide to rebuild your mags Brownell's has rebuild kits with new springs and followers or you could get just the springs Wolff is probably the best bet on that item.
MetalgodZ
NES Member
Regarding the poor cycling, failure to feed w/ a dent in the round, and failure to lock the bolt back, I'll definitely agree that you should look at the mags...specifically sounds like a weak spring. Have you tried a known good mag?
Is there a forward assists on the upper? When it fails to chamber the first round, do you pull out the round, or are you pushing the bolt closed somehow? Does it feel gritty or do you get any hesitation if you chamber it slowly?
The 1st round failing to chamber might be the mag, but also might be something else. You say that the upper has no markings but the lower is preban, so I kind of suspect that the upper has seen a lot of rounds, and maybe the buffer spring has gotten weak or there is crud in the buffer tube from someone lubing it and then grit/dirt getting in there.
Is there a forward assists on the upper? When it fails to chamber the first round, do you pull out the round, or are you pushing the bolt closed somehow? Does it feel gritty or do you get any hesitation if you chamber it slowly?
The 1st round failing to chamber might be the mag, but also might be something else. You say that the upper has no markings but the lower is preban, so I kind of suspect that the upper has seen a lot of rounds, and maybe the buffer spring has gotten weak or there is crud in the buffer tube from someone lubing it and then grit/dirt getting in there.
the mags are 30rd gi, they are worn but don't seem to have any noticeable flaws
I usually pull the bolt back a few times to bump the round forward then use the forward assist if needed.
I will check the buffer tube to see if its got some crap in it
edit
Ok, I checked the buffer tube it was a little dirty but not too bad.
I usually pull the bolt back a few times to bump the round forward then use the forward assist if needed.
I will check the buffer tube to see if its got some crap in it
edit
Ok, I checked the buffer tube it was a little dirty but not too bad.
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Run us a list:
Type of ammo:
Followers on mags - black, green, other:
Upper - full size, (20"), mid-length, cabine:
Stock - full size or collapsable:
Bolt carrier group - (Colt factory, M-16, AR-15, other)
Also, does your bolt stay back with an empty magazine inserted and manually pulling the bolt back?
Type of ammo:
Followers on mags - black, green, other:
Upper - full size, (20"), mid-length, cabine:
Stock - full size or collapsable:
Bolt carrier group - (Colt factory, M-16, AR-15, other)
Also, does your bolt stay back with an empty magazine inserted and manually pulling the bolt back?
55-56 gr wolf, pmc, and russian golden tiger (havent used the golden tiger yet)
mags followers are black
the upper is an unmarked flat top with a 20" barrel the barrel is marked 556 but I can find any other markings on it unless the gas block is covering them up.
stock is full sized
bolt carrier group im not too sure about its not marked. any tips on how I would tell.
and no the bolt doesnt stay open even when the mags are empty
mags followers are black
the upper is an unmarked flat top with a 20" barrel the barrel is marked 556 but I can find any other markings on it unless the gas block is covering them up.
stock is full sized
bolt carrier group im not too sure about its not marked. any tips on how I would tell.
and no the bolt doesnt stay open even when the mags are empty
does your bolt face look like
THIS
OR THIS
THIS
OR THIS
Hey Vin, where are you located? You can eliminate a lot of the possible issues if you're side by side with another AR (swap out magazines, swap uppers, compare bolts, etc). There are plenty of guys, myself included, who'd be happy to meet up with you.
This +1 if anything we have posted so far hasn't worked then get together with a fellow NES'r near by and start trouble shooting.
Your BCG seems fine. The FTF problem im almost certain is bad mag spring tension. As far as the bolt catch not holding I am leaing towards the bolt catch itself being damaged or not installed right. Coiuld you get some detailed pics of your lower from the top?
I'm with the try under loading the mags first crowd (28 rounds).
That may or may not be the problem, but it's the simplest start.
One of the most common arguments with AR owners is regarding "should I, or shouldn't I under load my mags"?
Whether or not one agrees with that is dependent on the situation... is this a SHTF or combat scenario, or casual shooter/plinking gun?
Mag springs could be weakened and need to be replaced at times (with result being failures to feed), but that's not the reason for under loading.
The reason for under loading is that in the event that the bolt carrier is fully forward, and a mag change is needed, inserting the mag can be difficult.
Regarding the dent in the casing (and since the bolt catch isn't functioning properly), if you're loading the mags to full capacity, and the bolt carrier was closed, and you had to force the mag in order for it to seat, it's possible that could be the cause for the dent.
Is that your problem? Maybe.
Another more likely possibility, is that the dent was already there when you loaded the mag and just didn't notice it.
That may or may not be the problem, but it's the simplest start.
One of the most common arguments with AR owners is regarding "should I, or shouldn't I under load my mags"?
Whether or not one agrees with that is dependent on the situation... is this a SHTF or combat scenario, or casual shooter/plinking gun?
Mag springs could be weakened and need to be replaced at times (with result being failures to feed), but that's not the reason for under loading.
The reason for under loading is that in the event that the bolt carrier is fully forward, and a mag change is needed, inserting the mag can be difficult.
Regarding the dent in the casing (and since the bolt catch isn't functioning properly), if you're loading the mags to full capacity, and the bolt carrier was closed, and you had to force the mag in order for it to seat, it's possible that could be the cause for the dent.
Is that your problem? Maybe.
Another more likely possibility, is that the dent was already there when you loaded the mag and just didn't notice it.
I will try underloading my mags next time. Also if the is no mag in the ar15 and I pull the bolt back and press the bolt release to get the bolt to stay open it doesnt, it slips off and slides forward. the only way I can get the bolt to stay open is to grab the brolt release with my thumb and forfinger and pull it back as far as it will go and then usualy it will stay open.
It is mostly a plinking gun for now, unless I decide to go for a diferent build later.
lets say I decide get a new bolt carrier group, does it matter what kind I get or do I have to get the exact same design as the one I have now,
It is mostly a plinking gun for now, unless I decide to go for a diferent build later.
lets say I decide get a new bolt carrier group, does it matter what kind I get or do I have to get the exact same design as the one I have now,
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So with no mag the bolt shouldn't lock on it own that's normal. By the way you explained it there it seems
like you don't have a detent spring. As far as a new BCG any one will work just buy a quality piece (LMT,BCM,SPIKES)
like you don't have a detent spring. As far as a new BCG any one will work just buy a quality piece (LMT,BCM,SPIKES)
If the bolt carrier photos are just as the carrier came out of the rifle, it's dry. Run the bolt carrier really wet! Put some lube into the vent holes on the port side of the carrier, work the bolt back and forth a few times, add a bit more oil. Do not use grease on a bolt carrier.
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Am I the only one who thinks this could be a gas tube issue? It sounds like the bolt isn't being thrown back far enough. Could also be a lack of lube as someone else pointed out.
By the way, I'm no AR expert but when I built my NES AR it wasn't cycling because the hole in the gas tube block was slightly out of alignment and the gun wouldn't feed and/or stay open on an empty mag.
By the way, I'm no AR expert but when I built my NES AR it wasn't cycling because the hole in the gas tube block was slightly out of alignment and the gun wouldn't feed and/or stay open on an empty mag.
i would think that too but it seems he is having the problem during the charging cycle not just the firing cycle.
