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Posted: 8/4/2013 12:44:21 PM EDT
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I recently purchased a new Ar. I took out the original BCG and replaced it with a chrome one. This may have been a mistake. After taking it to the range for sighting I had no issues originally, but after getting out this weekend and trying to put it through the paces I ran into some extraction and double feeding issues. Singe fire was generally fine, but If I tried to put any rapid shots down range I would run into the problem of the case (I only shot .223 brass before you ask) not extracting and some cases actually getting stuck to where I would have to hit the charging handle on a hard edge to get it and the BCG unstuck.
Each time this occurred, I would also get a double feed, some to the point it would shove the actual bullet deep into the casing. I've done quite a bit of research (yes, I used the search feature here in the forums) and can't come up with much. I'm a lonkg time lurker, actual new member, so posting was a bit of a last resort. I'm not a complete rookie when it comes to ARs, but I'm by no means and expert either. Any help would be greatly appreciated before I decide to buy a new BCG or send the rifle itself back to the manufacturer. Additional info: When I baby the BCG into the receiver, it sometimes doesn't completely seat, needing the forward assist to help it. This is usually once every 20 times. I know to let the rifle do it's job, but none of my other rifles have this issue whatsoever. Also I have tried one other M16 BCG with only one extraction issue. Finally, I do not know the make of the problem BCG in question. It was just a standard milspec group I bought from a trusted in house dealer. He said they were GTG. That's all the info I can give. Now pictures. Receiver (Sorry for the feet :/) http://i.imgur.com/ihMqAhfl.jpg http://i.imgur.com/d6QeSgbl.jpg http://i.imgur.com/kOpUTHKl.jpg http://i.imgur.com/acpvJ6ul.jpg From the Ejection Port http://i.imgur.com/8jUngUXl.jpg Bolt http://i.imgur.com/ogrq5tQl.jpg http://i.imgur.com/kxEv6RJl.jpg Group Face (That is an indention on the right side not fowling) http://i.imgur.com/NcuQBQEl.jpg And the brass. I couldn't get a bette picture, but that is where the extractor holds the brass. It definitely doesn't look normal. http://i.imgur.com/E2xI3gel.jpg |
Well it appears your problem is the pubic hair in the chamber (second pic). Your rifle could use some manscaping.  In all seriousness though we need to know who made the BCG and the barrel.
Eta: is it a chromed BCG or a coated BCG (NiB, Ceramic or what ever). Sometimes these coatings can cause the BCG to be out of spec. This is usually only from the lower end manufacturers. |
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The make is Smith and Wesson MP15 ORC. I did not add this as I didn't feel it was relevant. As I stated I don't know the maker of the BCG. I bought it from a local police officer who is also a class 3 dealer. He runs things from his house. He bought them from a distributor website in bulk. The were just standard milspec groups, no markings to indicate who manufactured them, or what company they would eventually go to.
I also stated I used regular .223 brass. Just brass. And I replaced the original with the chrome for easier cleaning at range sessions. Just wipe and go. Also I'm an idiot. |
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Yea, sorry I didn't bother cleaning it before hand. Was just frustrated and wanted it fixed. I have 3 cats so keeping hair away from a well lubed rifle is kind of hard.
The barrel is on a Smith and Wesson MP15 ORC 1/9 Twist. I guess they just recently started using these, because my understanding is that they used to have the 5r barrels. And again the bolt carrier group is chromed. So that could be the issue as I don't know the actual manufacturer. |
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Yea, sorry I didn't bother cleaning it before hand. Was just frustrated and wanted it fixed. I have 3 cats so keeping hair away from a well lubed rifle is kind of hard. The barrel is on a Smith and Wesson MP15 ORC 1/9 Twist. I guess they just recently started using these, because my understanding is that they used to have the 5r barrels. And again the bolt carrier group is chromed. So that could be the issue as I don't know the actual manufacturer. There's your first problem. A BCG is one of those components which should be purchased from a known manufacturer, or at least one whom meets certain specifications. If the chrome is not flaking off, a chrome lined BCG should be fine, if it is a quality BCG to begin with |
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I think you just stated your problem right there. Quoted:
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As I stated I don't know the maker of the BCG. I bought it from a local police officer who is also a class 3 dealer. He runs things from his house. He bought them from a distributor website in bulk. I think you just stated your problem right there. Well, by in bulk, I mean he bought a few of them. These are bolts manufactured for actual AR companies (DPMS, S&W, Colt, Stag, etc.) to purchase and label or put in their ARs. |
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Just for the limited info you wont get many answers. Did the gun run before you switched? What mags? With the double feeds its can be a mag issue. What ammo? Bottom line, you need to put 1 round in a mag, shoot it, see if the bolt locks back. Try that with 556 as well as 223. If it fails its a gas problem. If it doesn't, I would bet a mag problem. If that still doesn't work, known good ammo, and known good mags, it would look at extractor/ejector. After that its a headspace problems or something else. All I got time for without shooting it. |
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Just for the limited info you wont get many answers. Did the gun run before you switched? What mags? With the double feeds its can be a mag issue. What ammo? Bottom line, you need to put 1 round in a mag, shoot it, see if the bolt locks back. Try that with 556 as well as 223. If it fails its a gas problem. If it doesn't, I would bet a mag problem. If that still doesn't work, known good ammo, and known good mags, it would look at extractor/ejector. After that its a headspace problems or something else. All I got time for without shooting it. This. Also, can we see a pic of the extractor/spring/insert/o-ring? (I missed that pic) Is the extractor claw dull? |
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Group Face (That is an indention on the right side not fowling) http://i.imgur.com/NcuQBQEl.jpg The lug on the bottom of the carrier is apparently nowhere near square, and the rest of the carrier looks quite a bit off from symmetrical. That's bad. I think it's obvious that your chrome BCG is the culprit, but since you don't have another group to swap it for, it's really not going to help you for anyone to tell you "it's the X on the Y that's causing the problem. Honestly, there seem to be multiple problems with this BCG. Fortunately, standard, parkerized carriers are coming down in price enough that having a spare is beginning to be a practical thing. You may have to skip lunches for a little while while you save up, but I'm pretty sure you need a new, standard bolt carrier group from a known good source. |
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Just for the limited info you wont get many answers. Did the gun run before you switched? What mags? With the double feeds its can be a mag issue. What ammo? Bottom line, you need to put 1 round in a mag, shoot it, see if the bolt locks back. Try that with 556 as well as 223. If it fails its a gas problem. If it doesn't, I would bet a mag problem. If that still doesn't work, known good ammo, and known good mags, it would look at extractor/ejector. After that its a headspace problems or something else. All I got time for without shooting it. I never ran it with the original BCG. Standard Gen 2 & 3 Magpul PMAGS. They have never given me issue before through my other ARs. The ammo was Gecco .223 target, two boxes or PPU .223 brass, and one magazine had standard CMC 5.56 NATO Surplus. All gave me issues. The bolt locks back just fine once the last round in the magazine is shot. It's mostly rapid fire is when issues occur. |
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This. Also, can we see a pic of the extractor/spring/insert/o-ring? (I missed that pic) Is the extractor claw dull? Quoted:
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Just for the limited info you wont get many answers. Did the gun run before you switched? What mags? With the double feeds its can be a mag issue. What ammo? Bottom line, you need to put 1 round in a mag, shoot it, see if the bolt locks back. Try that with 556 as well as 223. If it fails its a gas problem. If it doesn't, I would bet a mag problem. If that still doesn't work, known good ammo, and known good mags, it would look at extractor/ejector. After that its a headspace problems or something else. All I got time for without shooting it. This. Also, can we see a pic of the extractor/spring/insert/o-ring? (I missed that pic) Is the extractor claw dull? I'm not 100% sure. I'm not quite that knowledgable as to what a worn one looks like. It did take a beating when having to strip the stuck bolt carrier out however. |
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Funny you should comment, I just purchased a new BCG from you guys to replace this one. Hope you guys work out better than this one. Quoted:
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That's a uniquely shaped BCG. Funny you should comment, I just purchased a new BCG from you guys to replace this one. Hope you guys work out better than this one. Oof. Did you get my message? 
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[Tilc']INDEED![/Tilc'] OP, you need to get your money back on that carrier, it is beyond fubar. Quoted:
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That's a uniquely shaped BCG. [Tilc']INDEED![/Tilc'] OP, you need to get your money back on that carrier, it is beyond fubar. Nah, nothing he can do, unfortunately. No way to tell who made it. I'm sure it'll turn out alright, though. I guarantee it, in fact.
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What does your buffer spring measure from end to end?
What is the weight of your buffer? What is the diameter of your barrel's gas port? Is the AR a carbine or mid-length gas system? What is the barrel's length? Being it's a purchased AR; unless you have the tools or a gunsmith check it, knowing the gas port diameter is not possible. What has me wondering is that the weapon shoots single shots, and locks back on the last shot fired; but rapid firing in semi-auto is causing the malfunctions, and makes me wonder if its a gas timing problem that is jamming things up. |
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Let me guess, you want that one to be the star attraction in your own personal Bolt Carrier freak show so you are going to make him an offer he can't refuse? I'm not going to say I have a freak show BCG paperweight collection. I won't deny it, but I'm not saying it either. 
But seriously, every manufacturer has their defects, as you well know. It's the nature of the beast. |
| The picture of your extractor (I don't know what problems it can cause) check to see if your extractor spring is upside down; the wider end of the spring is placed into the extractor, making sure it's seated by twisting it as you press down per TM 9-1005-319-23&P. |
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The lug on the bottom of the carrier is apparently nowhere near square, and the rest of the carrier looks quite a bit off from symmetrical. That's bad. I think it's obvious that your chrome BCG is the culprit, but since you don't have another group to swap it for, it's really not going to help you for anyone to tell you "it's the X on the Y that's causing the problem. Honestly, there seem to be multiple problems with this BCG. Fortunately, standard, parkerized carriers are coming down in price enough that having a spare is beginning to be a practical thing. You may have to skip lunches for a little while while you save up, but I'm pretty sure you need a new, standard bolt carrier group from a known good source. Quoted:
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Group Face (That is an indention on the right side not fowling) http://i.imgur.com/NcuQBQEl.jpg The lug on the bottom of the carrier is apparently nowhere near square, and the rest of the carrier looks quite a bit off from symmetrical. That's bad. I think it's obvious that your chrome BCG is the culprit, but since you don't have another group to swap it for, it's really not going to help you for anyone to tell you "it's the X on the Y that's causing the problem. Honestly, there seem to be multiple problems with this BCG. Fortunately, standard, parkerized carriers are coming down in price enough that having a spare is beginning to be a practical thing. You may have to skip lunches for a little while while you save up, but I'm pretty sure you need a new, standard bolt carrier group from a known good source. It's not suppose to be square, if it's not ramped off angle, it's not to what folks around here would argue is "Mil Spec" It's suppose to look like that. |
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It's not suppose to be square, if it's not ramped off angle, it's not to what folks around here would argue is "Mil Spec" It's suppose to look like that. Quoted:
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Group Face (That is an indention on the right side not fowling) http://i.imgur.com/NcuQBQEl.jpg The lug on the bottom of the carrier is apparently nowhere near square, and the rest of the carrier looks quite a bit off from symmetrical. That's bad. I think it's obvious that your chrome BCG is the culprit, but since you don't have another group to swap it for, it's really not going to help you for anyone to tell you "it's the X on the Y that's causing the problem. Honestly, there seem to be multiple problems with this BCG. Fortunately, standard, parkerized carriers are coming down in price enough that having a spare is beginning to be a practical thing. You may have to skip lunches for a little while while you save up, but I'm pretty sure you need a new, standard bolt carrier group from a known good source. It's not suppose to be square, if it's not ramped off angle, it's not to what folks around here would argue is "Mil Spec" It's suppose to look like that. |
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What has me wondering is that the weapon shoots single shots, and locks back on the last shot fired; but rapid firing in semi-auto is causing the malfunctions, and makes me wonder if its a gas timing problem that is jamming things up. I was thinking the same thing. As others have mentioned, you need to eliminate variables.
Best of luck to you. Edited to fix blockquote |
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The lug is supposed to be parallel to the flat on the top of the carrier. The front is supposed to have a bevel front-to-back. That one has the lug at an angle left-to-right... That's what I meant by "square." I thought that was pretty obvious, but I guess I should be specific... Quoted:
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Group Face (That is an indention on the right side not fowling) http://i.imgur.com/NcuQBQEl.jpg The lug on the bottom of the carrier is apparently nowhere near square, and the rest of the carrier looks quite a bit off from symmetrical. That's bad. I think it's obvious that your chrome BCG is the culprit, but since you don't have another group to swap it for, it's really not going to help you for anyone to tell you "it's the X on the Y that's causing the problem. Honestly, there seem to be multiple problems with this BCG. Fortunately, standard, parkerized carriers are coming down in price enough that having a spare is beginning to be a practical thing. You may have to skip lunches for a little while while you save up, but I'm pretty sure you need a new, standard bolt carrier group from a known good source. It's not suppose to be square, if it's not ramped off angle, it's not to what folks around here would argue is "Mil Spec" It's suppose to look like that. I must be missing something, it looks just fine to me, the feature directly below the gas key is a little wierd ( right in front of the cam pin slot) but I don't see anything out of the ordinary beyond that. OP, is there any markings inside the extractor pocket on the bolt? |
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I must be missing something, it looks just fine to me, the feature directly below the gas key is a little wierd ( right in front of the cam pin slot) but I don't see anything out of the ordinary beyond that. Unless there's a trick of the light going on and all I'm seeing is the bevel on the front, the bottom of that carrier looks like it is at a significant angle, where it should be flat enough to let the carrier rest flat on a table. |
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Unless there's a trick of the light going on and all I'm seeing is the bevel on the front, the bottom of that carrier looks like it is at a significant angle, where it should be flat enough to let the carrier rest flat on a table. Quoted:
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I must be missing something, it looks just fine to me, the feature directly below the gas key is a little wierd ( right in front of the cam pin slot) but I don't see anything out of the ordinary beyond that. Unless there's a trick of the light going on and all I'm seeing is the bevel on the front, the bottom of that carrier looks like it is at a significant angle, where it should be flat enough to let the carrier rest flat on a table. Enhance... Enhance!!!... ENHANCE!!!!!!!.... 
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question....
Why did you change out the BCG in the first place? Was it to have a cool chrome BCG? Best advice is to actually shoot the rifle before you get all tacticool because well... you found out the hard way what could happen. When you hear people say "Buy Once Cry Once" it is for a good reason. Quality yeilds the best results! |
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You said it jammed with other BCG's, right?
It sounded like a mag issue to me, but p-mags are pretty good. If you are having to mortar the rifle or pull hard on the CH to get the round out of the chamber, then you have other issues. Are the jammed rounds unfired? If they are, then you might be dealing with an overgassed rifle that damages the brass going up the feed ramps. I had one rifle that would do that when new. Replaced the buffer with a Spikes T2 and put several thousand rounds through it. It was fine after that. If its a carbine gas with a standard buffer, then I'd start there. If its double feeding and the jammed round is fired, then look at your extractor. Combo of a tight chamber and weak extractor can cause that. I see an extractor o-ring. Those scare me. I run the BCM springs and have had great reliability without the o- ring. With the o-ring my cases were getting pretty buggered up. Otherwise.... Give that thing a real good cleaning with solvent and a chamber brush. I've had dirty, tight new chambers cause issues with reputable rifles. ETA: missed that last picture. That carrier is FUBAR. Who made that thing? Geez... |
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Yep, you're right. Disregard my drivel. That's still one funky looking carrier though. Quoted:
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Enhance... Enhance!!!... ENHANCE!!!!!!!.... Yep, you're right. Disregard my drivel. That's still one funky looking carrier though. Even in it's enhanced state, it still looks a little off to me now that I look at it, I think you are correct, It looks a little wanky. 
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I must be missing something, it looks just fine to me, the feature directly below the gas key is a little wierd ( right in front of the cam pin slot) but I don't see anything out of the ordinary beyond that. OP, is there any markings inside the extractor pocket on the bolt? Quoted:
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Group Face (That is an indention on the right side not fowling) http://i.imgur.com/NcuQBQEl.jpg The lug on the bottom of the carrier is apparently nowhere near square, and the rest of the carrier looks quite a bit off from symmetrical. That's bad. I think it's obvious that your chrome BCG is the culprit, but since you don't have another group to swap it for, it's really not going to help you for anyone to tell you "it's the X on the Y that's causing the problem. Honestly, there seem to be multiple problems with this BCG. Fortunately, standard, parkerized carriers are coming down in price enough that having a spare is beginning to be a practical thing. You may have to skip lunches for a little while while you save up, but I'm pretty sure you need a new, standard bolt carrier group from a known good source. It's not suppose to be square, if it's not ramped off angle, it's not to what folks around here would argue is "Mil Spec" It's suppose to look like that. I must be missing something, it looks just fine to me, the feature directly below the gas key is a little wierd ( right in front of the cam pin slot) but I don't see anything out of the ordinary beyond that. OP, is there any markings inside the extractor pocket on the bolt? No no markings to mention. |
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