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Posted: 12/18/2013 6:52:59 PM EDT
I have a bcm 14.5 midlength upper which has been having some issues. Yesterday I took it to the range and shot 30-40 rounds of 5.56 ammo which worked fine. Then I started using this american eagle .223 55 gr fmj ammo and that where the problems started. It started jamming the casing in between the bolt and the chamber opening when loading a new round. Then it started becoming a single fire rifle. I had to charge the weapon after each shot. In the beginning i was using an h buffer but then switched to a c buffer when I started having the ftf problems. This did not help. Im not sure if the american eagle is just underpowered, but i was under the impression it was full powered ammo. I got about 100 rounds total in this range trip before i gave up and left frustrated. This seems to always happen to me when going to the range. The first couple mags are fine but then when the rifle gets heated up it starts jamming up on me. I know bcm's are made to run with full power 5.56 ammo, but i feel like my rifle shouldn't be having this many problems just because the ammo is .223 or slightly underpowered. Especially since I am about 600 rounds into the rifle. Do I need to get my gas port drilled wider? Help me out, thanks!
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Need more detail, such as what solvents you use to clean and lube the rifle, and if you are using a chamber brush to clean the chamber?
Have you check the key to see if it leaking against the top of the carrier? Same with how the gas block was installed (if loctite was used), and if it is leaking against the barrel? The fact that the gun will run when fresh and cold, then to start to have problems at is heats up, points to the one of the above problems. |
| If you dont' have a standard carbine buffer in her try that first. Also make sure shes very well lubed. Other things to check are gas block alignment as well as the gas tube and also make sure your key on you bcg is not loose. Like I said in the beginning make sure you aren't running a heavier buffer before you do anything else. |
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Need more detail, such as what solvents you use to clean and lube the rifle, and if you are using a chamber brush to clean the chamber? Have you check the key to see if it leaking against the top of the carrier? Same with how the gas block was installed (if loctite was used), and if it is leaking against the barrel? The fact that the gun will run when fresh and cold, then to start to have problems at is heats up, points to the one of the above problems. I use EWL and lubed it very well this last trip to the range. Yes I use a chamber brush. No I have not check to see if there is gas leakage in the carrier or gas block. How do I check this? And I dont know how the gas block was installed. I bought the complete upper from BCM |
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If you dont' have a standard carbine buffer in her try that first. Also make sure shes very well lubed. Other things to check are gas block alignment as well as the gas tube and also make sure your key on you bcg is not loose. Like I said in the beginning make sure you aren't running a heavier buffer before you do anything else. I started using a c buffer mis way through the range trip and this had no effect. I used plenty of EWL lube. How do I check gas block alignment and the gas tube? |
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What type of 5.56 ammo were you using when it was working fine? Were you using a different magazine when you were having problems, or the same magazine? If you let the rifle cool down, will it the cycle fine again until it gets hot?
CY6 Greg Sullivan "Sully" SLR15 Rifles TheDefensiveEdge.com (763) 712-0123 |
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What type of 5.56 ammo were you using when it was working fine? Were you using a different magazine when you were having problems, or the same magazine? If you let the rifle cool down, will it the cycle fine again until it gets hot? CY6 Greg Sullivan "Sully" SLR15 Rifles TheDefensiveEdge.com (763) 712-0123 It was bulk federal ammo xm193. I swapped out different mags with the .223 american eagle ammo and all 4 of the pmags i used had problems, so I dont think its the mags. I did not try letting it cool down completely, ill try that next time and see what happens. |
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I don't think its the warm up, but rather the use of very underpowered loads, in a brand & model that is well known for not performing well with anything other than full power loads. Pretty much the same answer I gave in OP's other thread. Next range trip I will try nothing but high powered 5.56 rounds and see what happens. However I would still like to know if there's anything else to be done aside from getting a new upper. I want a rifle I can depend on, not a high maintinance rifle that only shoots the best ammo. Plus I've heard of other peoples 14.5 middys doing just fine with cheap ammo |
| I have this exact same upper from BCM and I had the exact same problem you had! After relubing my BCG it only has loading issues now. If you find a answer to your problem please post it on here! Im close to figuring out the issue but im guessing its because I didn't lube the BCG enough. |
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That carrier does not look very wet to me. Is it your picture or is one corner of your cam pin deformed? Also post a picture of the upper where the cam pin does it's magic... It was right after shooting so it wasnt as wet as usual. No i dont think its deformed, ill post a couple more angles just to make sure though. And ya ill post a pic of the inside of the upper. 
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I have this exact same upper from BCM and I had the exact same problem you had! After relubing my BCG it only has loading issues now. If you find a answer to your problem please post it on here! Im close to figuring out the issue but im guessing its because I didn't lube the BCG enough. Exactly what loading problems are you having? I will post if I find an answer. I contacted BCM so we'll see if they give me a fix |
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I have this exact same upper from BCM and I had the exact same problem you had! After relubing my BCG it only has loading issues now. If you find a answer to your problem please post it on here! Im close to figuring out the issue but im guessing its because I didn't lube the BCG enough. Exactly what loading problems are you having? I will post if I find an answer. I contacted BCM so we'll see if they give me a fix My situation was similar to yours - I built a new rifle - essentially a BCM 14.5 LW Midlength barrel + BCM gas block, took out to shoot, put around 80 rounds through it flawlessly and then the rounds started jamming between the BCG and magwell opening at a 45 degree angle. Even with a fresh magazine it turned out to be single shot/failure pattern. After talking with some people it seems to be a BCG problem since I didn't lube it enough. I relubed it with some generic grease, took it out shooting but the BCG extractor now wont "latch" onto the rounds correctly. Everything it pointing to a defunct BCG unfortunately, but I plan on trying 1 or 2 more things before getting a new one. Let me know what BCM tells you, most people have never heard of this problem before at all so it seems to be a BCG or BCM barrel problem, at least to me. |
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What brand is your BCG? could answer alot of questions.
I have a BCM 14.5 BFH Middy and it runs great with a spikes t2 buffer, I have also ran a C, H1, H2 without issues. Keep it well lubed. The only ammo I have found that she does not like is Tula crap. It will function fine with it but will not lock back the bolt after the mag is empty. |
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From the pics the bolt lugs are too dry, and the pic of the inside of the upper receiver and barrel lugs (barrel extension) looks to be bone dry. Put a drop of lube on each bolt lug so that it is wet, use a good quality lubricant like Slip2000 Extreme Weapons Lube "EWL" (my favorite). I would also suggest either wetting down the entire bolt carrier so it is wet, or wet down the inside of the upper receiver. Lack of lubrication will allow more friction as the bolt carrier travels forward and backwards, this rubbing friction produces heat, and that heat causes expansion of parts, which that expansion results in more friction (rubbing) due to tolerances being swelled, basically a vicious circle, so to reduce the friction (heat), you need to lubricate where metal rubs metal, thus reducing friction. Also the gas key staking looks like it is a little light, but I don't suspect that this is the current problem, only a possible future one. The gas tube looks like it is tweaked over to the ejection port side (right), which leads me to suspect that the barrel nut indexing is off, which will eventually result in erosion of the gas tube and carrier key (gas key), to fix this I would re-index the barrel nut so the gas tube free floats with a little left/right play in it so there is no excess friction as the carrier key mates with the gas tube, this is actually a very common problem that we see on many guns that cross our paths when teaching armorer courses.
CY6 Greg Sullivan "Sully" SLR15 Rifles TheDefensiveEdge.com (763) 712-0123 |
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Thanks, I will contact them Quoted:
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I agree. I do not like picky guns. Is this a complete upper build by BCM? You should contact them and have them check it out. They have excellent customer service. Thanks, I will contact them What did they say? Doesn't look like a Bravo BCG, which one did you use? |
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That's not a BCM marked BCG, leading me to believe it's another brand. Quoted:
That's not a BCM marked BCG, leading me to believe it's another brand. It's got some funky looking wear on the bolt lugs also 
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took it out shooting but the BCG extractor now wont "latch" onto the rounds correctly. Everything it pointing to a defunct BCG unfortunately, but I plan on trying 1 or 2 more things before getting a new one. If there's a rubber O ring around the extractor spring, get it out of there and see if that fixes your issue. The O ring is a fix for an issue with certain configurations, your configuration is pretty much the opposite and the O ring can cause a problem where the extractor is too stiff to snap over the case rim. Could also have a damaged or improperly made extractor. Extractors are not that expensive to get another and swap it out to test it, extractors are a good spare to have on hand in any event. Let me know what BCM tells you, most people have never heard of this problem before at all so it seems to be a BCG or BCM barrel problem, at least to me. I don't know what people you are talking to but this particular brand and barrel configuration is well known for cycling issues from insufficient gas when using non-5.56/military pressure ammo. I haven't had one in hand to measure the gas port but it seems to me like they need a slightly larger gas port if that user is going to shoot low powered ammo. |
| I don't know about all that I've done over 1k of tula through my bcm 14.5 middi with h2 buffer and have never had any problem except a ftf. If your BCG is not even budging your gas block is not aligned or something has completely clogged you gas port like a fresh rifleing bur. |
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