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Posted: 3/20/2014 2:45:59 PM EDT
| So this is my first AR and last as long as I live in Maryland. Its a Core15 complete rifle. I will try to explain this as clearly as possible but may be confusing. I took everything apart to pretreat and inspect before firing. I loaded a mag(pmag) pulled charging handle, released and the round jammed between the bolt and reciever below feed ramp. So then I tried to lock the CH and release it and the round fed in the chamber so I dropped the mag and went to clear the chamber(not planning on firing gun just checking function) and I could not pull the CH back. I had to hold the rifle with my feet and pull it with everything I had to get the bolt(or whatever) unstuck. So I switched to the mag that came with the gun(cheap master molder) and the round fed fine when charging by hand but when releasing the locked bolt it go stuck again. Theres a clear difference in the angle of the bullet between the 2 mags. Magpul is flat and other one is angled up. but Im not sure about everything getting stuck. any ideas. Before I call Core I want to make sure In didnt screw anything up. Also there is marring on the rim of the rounds I cleared after bolt got stuck. thanks |
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without a mag in the gun, and no live ammunition. If you lock the bolt back then hit the release, is it still hard to pull back after the bolt was in battery?
If it is, your BCG may be suspect as the bolt isnt rotating properly, or as freely as it should. If it pulls back fine, and it is only when there is a round chambered, I would suspect the chamber is fubar and the round is being forced into a chamber that is too tight causing you to have to yank out the round harder than you should have had to. If im understanding everything correct can you post pics of your barrel extension/feed ramps and of your BCG from multiple angles? |
| Also for safety sake, if the BCG is stuck forward with a live round, place the rifle on safe, hold it vertical with muzzle straight up. While pulling on the charging handle, hit the buttstock downward on a firm surface. This will give the BCG downward momentum and making the extraction of the round much easier and more safe. |
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Ok so when I let the ch down easy its stops as shown in the first picture. Not sure if this is normal? Here are some pics of the feed ramps and where the bullet its the feed ramps with the pmag(I thought it was just below but I was wrong) Like I said the other mag works fine. I slammed one round in and it got stuck and there is marring and scarring on the bullet but cartridge seems to be ok. I will post pic soon thanks
http://i43.photobucket.com/albums/e356/payperwayte/IMG_0310_zps923ca2c8.jpg http://i43.photobucket.com/albums/e356/payperwayte/IMG_0311_zps60aa3a95.jpg http://i43.photobucket.com/albums/e356/payperwayte/IMG_0314_zps651c41eb.jpg |
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Quoted:
Ok so when I let the ch down easy its stops as shown in the first picture. Not sure if this is normal? Here are some pics of the feed ramps and where the bullet its the feed ramps with the pmag(I thought it was just below but I was wrong) Like I said the other mag works fine. I slammed one round in and it got stuck and there is marring and scarring on the bullet but cartridge seems to be ok. I will post pic soon thanks <a href="http://s43.photobucket.com/user/payperwayte/media/IMG_0310_zps923ca2c8.jpg.html" target="_blank">http://i43.photobucket.com/albums/e356/payperwayte/IMG_0310_zps923ca2c8.jpg</a> <a href="http://s43.photobucket.com/user/payperwayte/media/IMG_0311_zps60aa3a95.jpg.html" target="_blank">http://i43.photobucket.com/albums/e356/payperwayte/IMG_0311_zps60aa3a95.jpg</a> <a href="http://s43.photobucket.com/user/payperwayte/media/IMG_0314_zps651c41eb.jpg.html" target="_blank">http://i43.photobucket.com/albums/e356/payperwayte/IMG_0314_zps651c41eb.jpg</a> You need to thoroughly clean the chamber, lube the BCG with CLP, and then test using ammo other than soft point. |
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I had this exact issue with my Spike's Tactical Dissipator upper. Rounds were getting stuck on the left feed ramp but not on the right. I carefully filed down the sharp edges of the feedramp with a jeweler's file until they weren't digging into the rounds anymore. I finished by polishing the filed areas with stone. Rifle feeds flawlessly now.
Picture I took of what it was doing: 
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there could be so many things wrong with this.
what i would first check is make sure extension is install properly and indexed right to the bolt. if rifle give you inconsistent engagement/relesae of the bolt from extension.. check and see if the barrel moves from the upper.. i had rifle where the index pin wore the upper receiver slot to big and my barrel was rotating even with proper barrel nut torque. i ended up replacing the upper receiver. |
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Ok heres the bolt. I guess if this is an issue with the rifle and not my fault Im gonna contact Core seeing how its brand new. Im still learning about this platform but I just know something off. I will clean the chamber out and see if anything changes.
http://i43.photobucket.com/albums/e356/payperwayte/IMG_0319_zps1482d41d.jpg http://i43.photobucket.com/albums/e356/payperwayte/IMG_0317_zps49ca71a7.jpg |
| You have 'bolt override' where the bolt doesn't pick up the case head on the way forward. Naturally the round stops and the bolt continues over it until jams, in the process usually ruining the round. Several reasons for this, usually a mag or mag catch problem. First, though, you always 'drop' the bolt when loading - that is, you hit the bolt release and let the bolt fly. Loading slowly can cause problems, esp. in new rifles. Before trying to load again, remove the charging handle and bolt carrier. Spray some kind of cleaner/lube into the upper and wipe it out. Spray it on the BCG and wipe off. Reassemble and hand-cycle at a fast rate without magazine or ammo( yank charging handle all the way back and release, about 100 times). Repeat the field strip/lube but this time leave the parts more wet than before. Now you can point the rifle in a safe direction and try to load again. Lock back the bolt, insert a mag with 3 rounds and drop the bolt. It should load. |
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From OPs pic I'm seeing bolt override too and a BCG in need of lube. Bolt lug corners have some shiny spots that I wouldn't think you would see on a new rifle. Feed ramps look like crap. Has ledge and not lined up possibly causing impact marks on bolt and making hard to extract cartridge. I'd ask for an RMA and tell CORE to take a class on AR assembly. These are just the problems easily seen from a couple pics. Who knows what other problems it has. JMO though.
ETA: Looking at second pic of bolt doesn't look as bad. Hard to tell from a pic. Assembly still looks sloppy though. |
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Quoted:
You have 'bolt override' where the bolt doesn't pick up the case head on the way forward. Naturally the round stops and the bolt continues over it until jams, in the process usually ruining the round. Several reasons for this, usually a mag or mag catch problem. First, though, you always 'drop' the bolt when loading - that is, you hit the bolt release and let the bolt fly. Loading slowly can cause problems, esp. in new rifles. Before trying to load again, remove the charging handle and bolt carrier. Spray some kind of cleaner/lube into the upper and wipe it out. Spray it on the BCG and wipe off. Reassemble and hand-cycle at a fast rate without magazine or ammo( yank charging handle all the way back and release, about 100 times). Repeat the field strip/lube but this time leave the parts more wet than before. Now you can point the rifle in a safe direction and try to load again. Lock back the bolt, insert a mag with 3 rounds and drop the bolt. It should load. This. You also might try fully loading your Pmags and let them sit for a few days. Also try downloading your mags by 2 And see if that helps. |
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Quoted:
You have 'bolt override' where the bolt doesn't pick up the case head on the way forward. Naturally the round stops and the bolt continues over it until jams, in the process usually ruining the round. Several reasons for this, usually a mag or mag catch problem. First, though, you always 'drop' the bolt when loading - that is, you hit the bolt release and let the bolt fly. Loading slowly can cause problems, esp. in new rifles. Before trying to load again, remove the charging handle and bolt carrier. Spray some kind of cleaner/lube into the upper and wipe it out. Spray it on the BCG and wipe off. Reassemble and hand-cycle at a fast rate without magazine or ammo( yank charging handle all the way back and release, about 100 times). Repeat the field strip/lube but this time leave the parts more wet than before. Now you can point the rifle in a safe direction and try to load again. Lock back the bolt, insert a mag with 3 rounds and drop the bolt. It should load. I will try this tomorrow and report back but in everyones opinion should the upper be sent back to Core regardless of how it turns out tomorrow? thanks everyone for all the help. |
| I see the problem the ramp cuts on the upper are not smooth to the barrel extensions ramp looks like there is a lip where the nose of the round is hanging up...I dont know if its the angle but the ramps on the receiver dont look like factory ones I have on CMT,BCM and Colt uppers or any factory upper ive built on....looks like a lip could be the uppers ramps were not cut right shape and nagle wise. |
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