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Posted: 3/30/2015 10:17:12 PM EDT
ok, here we go.
I've been monkeying around with one of my ARs for quite a while now trying to cure a failure to feed issue. first off, the rifle is a Core15 (upper, lower, barrel, buffer tube). Last month I sent the upper assembly back to Core15 in Florida for them to diagnose the problem. Along with the rifle I sent all of my testing notes and examples of the damaged brass. They sent me the rifle back with a note saying that they polished the feed ramps, fired 20 rounds and that the rifle functioned properly. ... not the case when I put the lower back on and go shoot. I get failure to feeds every other round, sometimes every round when using magpul p mags. The rifle functions better with the metal GI mags but I still encounter failure to feeds while using them. HERE is the kicker: I also own a stock Colt M4 so today I decided to take both rifles out and start swapping uppers and lowers. Here is what I found after 200 rounds. Core15 upper on Colt lower = functions properly with both GI mags and magpul mags Core15 lower on Colt upper= functions properly with both GI mags and magpul mags Core15 lower on Core15 upper= fail what the crap is going on here ? has anyone else gone through this crap or am I just the luckiest sack of shit on the planet ? yes, something is out of spec. my gut feeling is that both the core15 upper AND lower are out of spec and that when the two of them get together everything gets out of alignment. |
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Quoted:
ok, here we go. I've been monkeying around with one of my ARs for quite a while now trying to cure a failure to feed issue. first off, the rifle is a Core15 (upper, lower, barrel, buffer tube). Last month I sent the upper assembly back to Core15 in Florida for them to diagnose the problem. Along with the rifle I sent all of my testing notes and examples of the damaged brass. They sent me the rifle back with a note saying that they polished the feed ramps, fired 20 rounds and that the rifle functioned properly. ... not the case when I put the lower back on and go shoot. I get failure to feeds every other round, sometimes every round when using magpul p mags. The rifle functions better with the metal GI mags but I still encounter failure to feeds while using them. HERE is the kicker: I also own a stock Colt M4 so today I decided to take both rifles out and start swapping uppers and lowers. Here is what I found after 200 rounds. Core15 upper on Colt lower = functions properly with both GI mags and magpul mags Core15 lower on Colt upper= functions properly with both GI mags and magpul mags Core15 lower on Core15 upper= fail what the crap is going on here ? has anyone else gone through this crap or am I just the luckiest sack of shit on the planet ? yes, something is out of spec. my gut feeling is that both the core15 upper AND lower are out of spec and that when the two of them get together everything gets out of alignment. View Quote Sounds like a bad marriage.... |
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Maybe the mag catch location is machined slightly too low on the Core15 lower, but the feed ramps are lower/more forgiving on the Colt upper?
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What are you using for ammo?
Should be Lake City M193 or M855 to be a fair test of how the gun was manufactured to function. The ammo you are using might be slightly low on power/pressure. |
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Quoted:
ok, here we go. I've been monkeying around with one of my ARs for quite a while now trying to cure a failure to feed issue. first off, the rifle is a Core15 (upper, lower, barrel, buffer tube). Last month I sent the upper assembly back to Core15 in Florida for them to diagnose the problem. Along with the rifle I sent all of my testing notes and examples of the damaged brass. They sent me the rifle back with a note saying that they polished the feed ramps, fired 20 rounds and that the rifle functioned properly. ... not the case when I put the lower back on and go shoot. I get failure to feeds every other round, sometimes every round when using magpul p mags. The rifle functions better with the metal GI mags but I still encounter failure to feeds while using them. HERE is the kicker: I also own a stock Colt M4 so today I decided to take both rifles out and start swapping uppers and lowers. Here is what I found after 200 rounds. Core15 upper on Colt lower = functions properly with both GI mags and magpul mags Core15 lower on Colt upper= functions properly with both GI mags and magpul mags Core15 lower on Core15 upper= fail what the crap is going on here ? has anyone else gone through this crap or am I just the luckiest sack of shit on the planet ? yes, something is out of spec. my gut feeling is that both the core15 upper AND lower are out of spec and that when the two of them get together everything gets out of alignment. View Quote Tolerance stacking of mediocre parts. |
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did you build the lower ? you may need to tighten up the mag catch so that the button is flush with the end of the threaded portion
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but why does this core15 upper function properly with the Colt M4 lower ? http://www.smugmug.com/photos/i-2SBVNk2/0/L/i-2SBVNk2-L.jpg pretty sure that i will never buy anything from core15 again. im not even going to waste my time dealing with them over warrantee issues. just disappointed. ill go ahead and order a new upper receiver and barrel from bcm or some other company and see what happens. View Quote Before you just throw in the towel... Just a though but what buffer weight is in the core15? have you checked the spring? You might have too much bolt velocity. It is normally not a good idea to start replacing parts, until you know the parts you are replacing are truly bad. Does it mis-feed when you hand cycle it? |
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This is what you go back from the factory???? Hence an Industrial partner here??? Core Rifle Systems, Inc. 4600 W. Hwy 326 Ocala, Florida 34482 http://www.ar15.com/forums/f_2/385_Core_Rifle_Systems.html |
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yep, that is what I got back.
before I sent it to them I double checked the gas block, twice for alignment. tried two different buffer springs tried one of those flat wound buffer springs purchased and experimented with: carbine buffer h buffer spikes t1 buffer, t2 buffer and t3 buffer swapped bolt carrier groups with, colt bcg, spikes Niboron bcg ... believe me, ive have tried every-fucking-thing. im stumped other than these feed areas. maybe the gas port is too small?? I didn't check that. . but why would it work with the colt lower on it ? I haven't inspected the buffer tube itself... maybe that's the problem.. but it works on the colt upper.. im not one to bitch and complain; it just bothers me when I cant figure out what the problem is. thought I would post on here to get some ideas 'cause im shit out of them. I think the best thing to do is let it die and vulture it for usable parts. edit: wow, I didn't know core15 had its own section on the forum. I used the phone number on their web site first. this is probably my 5th or 6th post so I really don't know where to find things on this site. to core15's credit they were easy to deal with on the shipping process and turn around time. |
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The feeding issue, is it one one side? The magazine feeds from both the right and left sides.
CY6 Greg Sullivan "Sully" SLR15 Rifles TheDefensiveEdge.com (763) 712-0123 |
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take the spring and buffer set out of the Colt and swap it with the Core15 and see what happens. somebody really outdid themselves on that ramp job
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Just IM'd Core15 to chime in on this thread.
I want to see what they have to say/respond, before I go savage on the upper receiver extended ramp butcher job and get staff involved as well. |
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I am a noob too, but not inexperienced at tinkering with stuff.
It LOOKS from that photo, that someone took a polishing wheel too big for the job and polished a section that's unrelated to the "ramp" part in "feed ramp." Cartridges don't contact where they polished. They contact further in (where the barrel and the other part meet), and I see no evidence of polishing there. The point is, don't give up on polishing the ramp, they didn't do it. So doing it, could still fix the problem. |
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That is fugley. They need to issue a return shipping label to have the complete rifle sent back.
In part, Core's warranty states: " If anything is not up to your standard, accuracy included, if anything goes wrong, gets bent, broken, cracked, misaligned, tweaked, snapped or otherwise, simply contact one of our professionals and we will work to make it right. If you are the 5th owner and the rifle has seen 40k+ rounds, it simply….doesn't….matter. We stand behind our products and we take care of our customers. That is our promise and your assurance." |
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As the previous post states, our warranty is unconditional. We will replace anything that is not functional. Our warranty department has contacted you to have the complete rifle shipped back for repair.
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I am not an expert nor a genius, but your ammo pictures look as the bolt is not moving as back as it should, and it is not feeding the ammo properly. You might have plenty of things to check. Too heavy buffer, too strong spring, carrier is loosing preassure somewhere, gas tube dont fits thw carrier properly, etc etc etc. But I am sure there are experts at this forum that will help you better than me. I had a similar situation, and tried what I told you. What it was I cannot tell, but after cleaning and checking this parts issue was removed. Now the gun works perfectly.
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I tried to refrain from commenting, but when I (or any competent gunsmith) "polish" feed ramps you can literally see your reflection in them. If they aren't stainless they should be cold blued (I use Oxpho Blue) so as to be "professional."
Good on Core15 for stepping up! |
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I received everything back from core15.
they replaced the barrel and the gas block/ front sight. (thanks!) they told me that the taper pin holes on my barrel were out of alignment <---------- the buffer tube was loose when I received it so I tightened that up. I sent them the barreled upper, lower and buffer tube. they put the rifle together and tested 30 rounds through it and it functioned properly after installing new barrel and gas block. I believe that it did function properly. I appreciate the effort by core15 but Im still apprehensive about this rig. its just not the one I would grab if I had to fight. i'll likely just permanently mount one of my scopes on it and run 10 round mags in it. |
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Quoted:
I received everything back from core15. they replaced the barrel and the gas block/ front sight. (thanks!) they told me that the taper pin holes on my barrel were out of alignment <---------- the buffer tube was loose when I received it so I tightened that up. I sent them the barreled upper, lower and buffer tube. they put the rifle together and tested 30 rounds through it and it functioned properly after installing new barrel and gas block. I believe that it did function properly. I appreciate the effort by core15 but Im still apprehensive about this rig. its just not the one I would grab if I had to fight. i'll likely just permanently mount one of my scopes on it and run 10 round mags in it. View Quote Thanks for the update. It isn't very encouraging that they fail to even correctly install/stake the receiver extension. |
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Quoted:
I received everything back from core15. they replaced the barrel and the gas block/ front sight. (thanks!) they told me that the taper pin holes on my barrel were out of alignment <---------- the buffer tube was loose when I received it so I tightened that up. I sent them the barreled upper, lower and buffer tube. they put the rifle together and tested 30 rounds through it and it functioned properly after installing new barrel and gas block. I believe that it did function properly. I appreciate the effort by core15 but Im still apprehensive about this rig. its just not the one I would grab if I had to fight. i'll likely just permanently mount one of my scopes on it and run 10 round mags in it. View Quote They said the taper pin holes on the barrel were out of alignment? What kind of gas block does it have? Front sight base? You said you checked it twice. Did you actually remove it, taper pins and all? When you said it was failing to feed....besides the pictures of the damaged ammo you posted what exactly were you seeing as the feeding issue? Were you getting stoppages during feeding....BCG getting jammed mid travel? Double feeds? Single round jams? You got a new barrel now so perhaps we might never know the real issue. Did they repaint/refinish the lower in the M4 Feed ramp area where it was buffed? |
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The problem was ID early on when the upper worked on the Colt lower. The mag is not being held high enough in the Core lower so you're getting bolt override instead of picking the round up by the case head.
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have you put some rounds down it since you got it back ? does it function right ? if not I would not pass judgment on it yet and say its going to be a range run only
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no, I have not reassembled it yet, however it is sitting on my workbench in all of its wobbly glory waiting for me to find a purpose for it.
no, they did not refinish the lower. it looks the same as the pictures above. when I get it back together and shoot a few paper plates with it ill report back; but that could be a while. |
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A friend of mine had the exact same problem with his Core 15. He took it to a gunsmith friend of his, and figured out the problem. The buffer retaining pin was binding on the bolt carrier during operation. I don't recall what the brass looked like on the rounds that failed to feed, but I definitely remember failures to feed with that rifle. Check the carrier and the pin to see if there is any unusual wear. You can also just take the pin itself out and try running the rifle without it to see if that's the issue or not.
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