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7/1/2014 6:20:33 PM EDT
i have an ar15 by core15 i only shot 300 rounds out of it and after the last bullet gets fired my bolt doest stay lock back
and i have to keep charging it even putting a new mag in and i have no idea what can do this i dont know if my bolt catch is missed or recoil spring or what

i got check out where i bought it and they said it could be my mags and i only us p-mags from magpul


and i ideas will help
7/1/2014 7:14:04 PM EDT
[#1]
what kind of ammo are you using?
7/1/2014 7:17:04 PM EDT
[#2]
Start with a thorough cleaning and lubrication of the rifle.  Look around the front sight base or gas block area for any carbon build up like there is a gas leak.  Check the gas key staking.  What type of ammunition are you using, and have you tried a different ammo just to make sure that ammo is not the issue?


CY6
Greg Sullivan "Sully"
SLR15 Rifles
TheDefensiveEdge.com
(763) 712-0123    

7/2/2014 10:46:56 AM EDT
[#3]
I would check to see if the magazine follower lip makes contact with the bolt catch. If it doesn't then I'd get a metal mag. I've found the plastic versions can vary a bit so not to make the connection.
Sometimes it's also due to the spring in the mag not being strong enough to do the job. Check on that too.

Impala
7/4/2014 2:57:12 AM EDT
[#4]
that ammo i use is american eagle fmj  i don't remember what grain it was
but i toke it to a gunsmith near by he did a presser check of the gas block and said its working just fine
he look at all the mags i have and tried a metal mag and saw a little bar where the mag is sitting getting stuck for some reason and there was
some weird markings on the bolt its self
7/4/2014 2:57:56 AM EDT
[#5]
i lub and clean it once a week to make sure even if i dont fire it
7/4/2014 3:28:55 AM EDT
[#6]
Quote History
Quoted:
i lub and clean it once a week to make sure even if i dont fire it
View Quote

Way too much cleaning
7/4/2014 9:21:37 PM EDT
[#7]
i get bored a lot and have to much time on my hands lol plus i dont over lub it
7/5/2014 7:05:14 AM EDT
[#8]
Quote History
Quoted:
that ammo i use is american eagle fmj  i don't remember what grain it was
but i toke it to a gunsmith near by he did a presser check of the gas block and said its working just fine
he look at all the mags i have and tried a metal mag and saw a little bar where the mag is sitting getting stuck for some reason and there was
some weird markings on the bolt its self
View Quote


EvaCore,

I'm still pretty sure your issues in not with your bolt. I still believe it's your mags. It's still possible the mag springs are weak when it's constantly compressed with ammo. Wether metal or plastic they all can hang up slightly.

Your Magpuls.....push down on the follower and see if it's springs back up fast to make contact iwth the lips. It should be a fast motion. If it's slow then you know it has to be your spring as the condition happens oon the last round fired.

The metal ones give them a cleaning and apply a thin coating or oil oon the inside to minimize hang-up and smoother operation of the follower.

Impala
7/5/2014 9:48:09 AM EDT
[#9]
all the springs in the mags are fast going up even on the last round when i load the mag in place
with out the upper attached to the lower at all i wanted to see whats going on and
what i saw was some little metal bar or latch thing that the bolt catch was linked to
when u load a mag it hits this metal thing and it gets in the away of the mags
7/5/2014 7:48:26 PM EDT
[#10]
Quote History
Quoted:
all the springs in the mags are fast going up even on the last round when i load the mag in place
with out the upper attached to the lower at all i wanted to see whats going on and
what i saw was some little metal bar or latch thing that the bolt catch was linked to
when u load a mag it hits this metal thing and it gets in the away of the mags
View Quote


EvaCore,

I wonder if your mag walls vibrate under shooting and when your on your last round perhaps the mag vibrates/shifts a little in the mag well. How loose is it when your on the last round???Get a dummy cartridge and insert it in the mag. Perhaps it wobbles a little in the well.

Impala
7/6/2014 7:21:21 PM EDT
[#11]
Try loading a single round into each magazine, the firing it and see if it locks back on any of the magazines.  Can you manually cycle rounds through the rifle and get it to lock back on an empty magazine?

CY6
Greg Sullivan "Sully"
SLR15 Rifles
TheDefensiveEdge.com
(763) 712-0123
7/7/2014 1:30:54 PM EDT
[#12]
did you build the lower ? are you sure you put the right springs in the bolt catch and the plunger ? if that's not it have a look at this thread http://www.ar15.com/mobile/topic.html?b=3&f=66&t=479984
7/8/2014 8:58:24 AM EDT
[#13]
stack core 15 ar from the factory and the mags sit in the lower with out that much movement and i did a full cycle with out firing and still doesn't lock back
7/8/2014 8:59:48 AM EDT
[#14]
springs in the bolt catch and the plunger i can see being instill wrong by the factory
7/8/2014 9:41:10 AM EDT
[#15]
does the mag even lock in place or can you pull it out with out pushing the mag release
7/8/2014 9:50:35 AM EDT
[#16]
Do you have any friends with AR's where you can borrow a couple mags other than PMags? You need to try other mags before finding fault with the bolt or the bolt catch.

After trying different mags and getting the same result, give Core15 a call. they have very good customer service.
http://www.core15.com/
7/8/2014 8:21:26 PM EDT
[#17]
the mags lock in place and im the only out of my friends that only an AR sadly and i told the gunsmith if it need to be fix ether he can fix it or he can send it in to core15 for me so yea
7/11/2014 7:50:01 AM EDT
[#18]
Quote History
Quoted:
the mags lock in place and im the only out of my friends that only an AR sadly and i told the gunsmith if it need to be fix ether he can fix it or he can send it in to core15 for me so yea
View Quote


EvaCore,

If your smith can repair it as it only sounds like a parts replacement is necessary then I'd go for it.

In addition bear in mind that on my rifles they don't always lock back on the last round fired every time either. I really don't worry about it cuz all I looks for is a good cycling of the bolt itself and feeds well and the gas system is fine. Like I said before plastic injected mags can vary regardless of the brand and so that's why I don't worry about it.

Good luck and I hope everything works out well for you.

Impala
7/12/2014 4:54:53 AM EDT
[#19]
ok and i just pick up my ar from the smith he said when fired it and did a full breakdown of the ar he found the bolt catch and the where it sits wasn't milled right and repaired and milled the place where its sis and did anther fire test and it locks back every time
7/14/2014 5:54:07 AM EDT
[#20]
Quote History
Quoted:
ok and i just pick up my ar from the smith he said when fired it and did a full breakdown of the ar he found the bolt catch and the where it sits wasn't milled right and repaired and milled the place where its sis and did anther fire test and it locks back every time
View Quote


EvaCore,

I'm much glad everything worked out fine in your favor! It's kinda funny how everything say it's Mil-Spec and it turns out it's really not at all.
Heck even my issue with my rifle BCG turned out fine after I ran out and bought another completed BCG. Now my rifle races like a horse now.


Impala
7/16/2014 2:08:28 PM EDT
[#21]
yea ur right about that and i went to the range fired 100 roudsa and i notce the part needs some a braking due to some times it sticks closes but im not going to rant over a new part u know
but one thing for sure is i need to do some serious upgrades trigger for better pull and ect
7/31/2014 2:18:01 PM EDT
[#22]
contact Core!!!it doesnt matter where you bought it or if you bought it used...They have a LIFETIME NO BS WARRANTY..And trust me .....They stick to it....They will fix it....
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