- My Forums
- Tiger Rant
- LSU Recruiting
- SEC Rant
- Saints Talk
- Pelicans Talk
- More Sports Board
- Fantasy Sports
- Golf Board
- Soccer Board
- O-T Lounge
- Tech Board
- Home/Garden Board
- Outdoor Board
- Health/Fitness Board
- Movie/TV Board
- Book Board
- Music Board
- Political Talk
- Money Talk
- Fark Board
- Gaming Board
- Travel Board
- Food/Drink Board
- Ticket Exchange
- TD Help Board
Customize My Forums- View All Forums
- Show Left Links
- Topic Sort Options
- Trending Topics
- Recent Topics
- Active Topics
Started By
Message
AR15 having issues
Posted on 10/1/22 at 10:11 am
Posted on 10/1/22 at 10:11 am
LINK
I provided a link to some pictures. I recently had an upper built by a local gun store in BR. The lower is a complete BCM lower with an H buffer. The upper is a Colt upper receiver, Sons of Liberty Gun works 13.7 Combat Barrel, Sons of Liberty BCG, Aero Precision Gas Block and Gas tube. The gas system is mid length. I took it to the range and shot 350 rounds of brass PMC and various steel case. The first 150 rounds shot were brass. The very first bullet in the very first magazine jammed. Throughout the 350 rounds shot I probably had over 30 plus failure to feeds, failure to ejects, multiple times the bolt went forward but didnt load a round into the camber, and one time the bolt got so stuck trying to eject a round I had to physically use all my strength to pull the charging handle back to get it unstuck from the feed ramps on the barrel. For reference, I was using 5.56 and .223, the magazines I was using were Gen 3 PMAGS and Surplus USGI Colt magazines. They have been used on multiple other guns with no problems and yes the gun was lubed properly. I took it back to the gun store that put it together and it was a young 20 something year old Marine who politely told me that 1. the feed ramps cannot be misaligned on an AR15 and thats a myth and he knew what he was talking about because he was a Marine and operated million dollar weapon systems. 2. that I didnt have it lubed properly. 3. That the steel case ammo was the problem. 4. he then said that the gun just needed to be run harder and that his Daniel Defense rifle had that problem at first and his new Sig Macro jammed the first round. He took my gun and said he would take it to the range and shoot it himself and try to figure out what is wrong. I had a former US Army 91f Armorer take a look at these pictures and he said the feedramps are not aligned, to check the headspace and gas tube alignment and said that kid was a moron and was wrong and to take the gun to someone else before they frick it up even worse. The rounds are getting hung up on the feed ramp. One of the pictures I included is a picture of the BCG not going all the way forward into battery when I rack a round which to me seems like the feed ramps arent aligned causing the BCG lugs to not sit properly in the feed ramps. If anyone has any suggestions on what they believe is the problem or who I should take it to other than this gun store I would appreciate it.
I provided a link to some pictures. I recently had an upper built by a local gun store in BR. The lower is a complete BCM lower with an H buffer. The upper is a Colt upper receiver, Sons of Liberty Gun works 13.7 Combat Barrel, Sons of Liberty BCG, Aero Precision Gas Block and Gas tube. The gas system is mid length. I took it to the range and shot 350 rounds of brass PMC and various steel case. The first 150 rounds shot were brass. The very first bullet in the very first magazine jammed. Throughout the 350 rounds shot I probably had over 30 plus failure to feeds, failure to ejects, multiple times the bolt went forward but didnt load a round into the camber, and one time the bolt got so stuck trying to eject a round I had to physically use all my strength to pull the charging handle back to get it unstuck from the feed ramps on the barrel. For reference, I was using 5.56 and .223, the magazines I was using were Gen 3 PMAGS and Surplus USGI Colt magazines. They have been used on multiple other guns with no problems and yes the gun was lubed properly. I took it back to the gun store that put it together and it was a young 20 something year old Marine who politely told me that 1. the feed ramps cannot be misaligned on an AR15 and thats a myth and he knew what he was talking about because he was a Marine and operated million dollar weapon systems. 2. that I didnt have it lubed properly. 3. That the steel case ammo was the problem. 4. he then said that the gun just needed to be run harder and that his Daniel Defense rifle had that problem at first and his new Sig Macro jammed the first round. He took my gun and said he would take it to the range and shoot it himself and try to figure out what is wrong. I had a former US Army 91f Armorer take a look at these pictures and he said the feedramps are not aligned, to check the headspace and gas tube alignment and said that kid was a moron and was wrong and to take the gun to someone else before they frick it up even worse. The rounds are getting hung up on the feed ramp. One of the pictures I included is a picture of the BCG not going all the way forward into battery when I rack a round which to me seems like the feed ramps arent aligned causing the BCG lugs to not sit properly in the feed ramps. If anyone has any suggestions on what they believe is the problem or who I should take it to other than this gun store I would appreciate it.
5
Posted on 10/1/22 at 10:22 am to AdmiralApe
I had a problem with a bolt face being machined wrong.
Wouldn't load a round in the chamber and if it did it would come out.
Mic'd the ID of the bolt face and got online and looked up bolt face IDs and got as close to a common round as possible.
They labeled a 6.5 Grendel I think it was as a 7.62 bolt.
Close but enough for a micrometer to tell the difference.
Swap a bolt from another and see if it does it.
I had to use everything I had to get that damn charging handle back to eject the round stuck in there.
Previous post on the bolt face. stamped wrong.
Wouldn't load a round in the chamber and if it did it would come out.
Mic'd the ID of the bolt face and got online and looked up bolt face IDs and got as close to a common round as possible.
They labeled a 6.5 Grendel I think it was as a 7.62 bolt.
Close but enough for a micrometer to tell the difference.
Swap a bolt from another and see if it does it.
I had to use everything I had to get that damn charging handle back to eject the round stuck in there.
Previous post on the bolt face. stamped wrong.
This post was edited on 10/1/22 at 10:26 am
Posted on 10/1/22 at 10:25 am to thejudge
I swapped a BCM BCG into it from a friends rifle for one magazine and it had no problems but not every magazine I fired with my BCG had a problem so I don’t know for certain if thats a problem. I wish I had used his BCG in my rifle for a bit longer but we ran out of ammo unfortunately.
Posted on 10/1/22 at 10:32 am to thejudge
quote:. 6.5 gr and 7.62x39 are the same bolt face, FYI
They labeled a 6.5 Grendel I think it was as a 7.62 bolt.
OP. No idea if the ramps are misaligned. It may be the upper that is cut incorrectly.
Is see that the barrel’s ramps and the uppers ramps are off slightly.
The barrel has an index pin on the top of the barrel that aligns the barrel and upper via a slot in the upper.
Swap your BCG and see if that helps.
Also, really clean that barrel and chamber. May have an imperfection in the chamber that is messing you up.
Posted on 10/1/22 at 10:33 am to AdmiralApe
I have a BCM and had issues with it not wanting to lock in a magazine. You really had to jam it in there just right and hard. 3rd time to the range with it and it started working fine. I read later sometimes their is a paint buildup or some little piece of debris in the way and that could of been what it was. Never had any issues besides that and once it went away it never came back.
Posted on 10/1/22 at 10:59 am to ReadyPlayer1
Don't load your mags all the way full and that may fix any hard mag catching issues.
Typically, you're supposed to load a "30 Rd" with 28 or 29.
Typically, you're supposed to load a "30 Rd" with 28 or 29.
Posted on 10/1/22 at 12:01 pm to AdmiralApe
Step 1. Name the place that charged you to build that upper.
Step 2. Have someone who has the proper tools and know how to assemble an upper to take that upper down and rebuild it.
Look, feed ramp alignment isn't critical, it just isn't however it is EASY to line up perfectly when assembling an upper. If this "gun smith" didn't take the time to align the barrel properly what else did they not do correctly? Was everything torqued correctly? Did they bother to check headspace? (I know it is virtually impossible to get headspace wrong on an AR15 that is properly assembled from proper parts but that assumes everything is proper, if you are charging you should check). Anyway the gun could work even if the ramps weren't even cut in the receiver.
I'd be curious to see what kind of spring or o ring was installed in that BCG. BCM has a upgraded version that is too strong and causes the issues you describe. I'd grab a pack of mil spec or "standard" springs and see if that helps before you do anything else.
Step 2. Have someone who has the proper tools and know how to assemble an upper to take that upper down and rebuild it.
Look, feed ramp alignment isn't critical, it just isn't however it is EASY to line up perfectly when assembling an upper. If this "gun smith" didn't take the time to align the barrel properly what else did they not do correctly? Was everything torqued correctly? Did they bother to check headspace? (I know it is virtually impossible to get headspace wrong on an AR15 that is properly assembled from proper parts but that assumes everything is proper, if you are charging you should check). Anyway the gun could work even if the ramps weren't even cut in the receiver.
I'd be curious to see what kind of spring or o ring was installed in that BCG. BCM has a upgraded version that is too strong and causes the issues you describe. I'd grab a pack of mil spec or "standard" springs and see if that helps before you do anything else.
Posted on 10/1/22 at 12:02 pm to Jack Ruby
quote:
Don't load your mags all the way full and that may fix any hard mag catching issues.
Typically, you're supposed to load a "30 Rd" with 28 or 29.
Why?
Posted on 10/1/22 at 12:11 pm to bbvdd
quote:
6.5 gr and 7.62x39 are the same bolt face, FYI
Yea I went back anD looked.
It was a 6.8 they sent me.
Couldn't remember which.
Posted on 10/1/22 at 1:21 pm to armsdealer
The store that assembled it was Louisiana Firearms off Old Hammond. They didnt even offer once to take it apart and reassemble it, nor did they even for one second admit they might have done something wrong, all they offered to do was take it to the range for me and shoot it and see whats wrong but I have to pay for the ammo. I highly doubt they checked the headspace or checked to make sure everything was fit correctly. He had the entire upper assembled in 20-30 minutes and 10 minutes of that was them trying to find the hand guard because they lost it.
Posted on 10/1/22 at 2:31 pm to Jack Ruby
quote:
Don't load your mags all the way full and that may fix any hard mag catching issues.
Typically, you're supposed to load a "30 Rd" with 28 or 29.
That's not an issue nowadays, especially with Pmags.
Posted on 10/1/22 at 9:01 pm to AdmiralApe
Thanks for naming the store, I will definitely stay away from there. Any reputable store would stand behind their build.
This post was edited on 10/1/22 at 9:03 pm
Posted on 10/1/22 at 9:04 pm to MetroAtlantaGatorFan
why not just buy a std gun that works cheaper
Posted on 10/1/22 at 9:14 pm to AdmiralApe
quote:
Louisiana Firearms off Old Hammond.
I don't know who is running that one, never stepped foot in it.
You can build an upper in 20 minutes properly, but they built it and did not test fire? That's lazy. I would be interested in what tools they used. You don't need fancy stuff but having some upper blocks and a reaction rod or similar with some good AR wrenches is important (not some multitool)
I still think you probably have the Extra strength BCM extractor spring/o ring and that causes a TON of the problems you described.
Posted on 10/2/22 at 8:04 am to AdmiralApe
Gas tube alignment
Strip down your bolt carrier group to just the carrier and see if it slides freely into the gas tube like in that guy’s video.
Feed ramps aren’t perfectly aligned but it might not even be your problem. I would check the gas tube alignment first. If that doesn’t work I’d try a different bolt carrier group.
Put one round in and see if it ejects around the 3 o’clock or 4 o’clock position. If the BCG and gas tube are aligned and it isn’t ejecting, your buffer spring or weight may be too stiff or you may not be getting enough gas (check your gas block alignment and port set screw). Once you get it cycling that way, still use one round at a time but this time insert a mag. Each cycle should lock the bolt back. If that works, then move on to multiple rounds in the mag at which point you’ll know if you need to realign or carefully file and smooth the ramps.
Or bring the whole gun to an armorer and be done.
Strip down your bolt carrier group to just the carrier and see if it slides freely into the gas tube like in that guy’s video.
Feed ramps aren’t perfectly aligned but it might not even be your problem. I would check the gas tube alignment first. If that doesn’t work I’d try a different bolt carrier group.
Put one round in and see if it ejects around the 3 o’clock or 4 o’clock position. If the BCG and gas tube are aligned and it isn’t ejecting, your buffer spring or weight may be too stiff or you may not be getting enough gas (check your gas block alignment and port set screw). Once you get it cycling that way, still use one round at a time but this time insert a mag. Each cycle should lock the bolt back. If that works, then move on to multiple rounds in the mag at which point you’ll know if you need to realign or carefully file and smooth the ramps.
Or bring the whole gun to an armorer and be done.
Posted on 10/3/22 at 1:36 pm to Squirrelmeister
quote:
Feed ramps aren’t perfectly aligned but it might not even be your problem. I would check the gas tube alignment first. If that doesn’t work I’d try a different bolt carrier group.
90 percent of what I see at the range is exactly this problem. Trying different mags might help
Posted on 10/3/22 at 7:52 pm to TideHater
quote:
exactly this problem.
Feed ramps, gas tube alignment, or BCG? Sorry I just want to make sure I understand your comment.
Posted on 10/3/22 at 8:18 pm to AdmiralApe
I have a 12.5 5.56 that was built by them that short strokes real bad
Posted on 10/4/22 at 5:40 pm to slinky225
I really hope they are aligning the gas blocks, that is really hard to actually frick up. You almost have to do it on purpose, everything has to be lined up to finish assembly...
Page 1 of 1
Back to top
Follow TigerDroppings for LSU Football News