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Posted: 1/31/2016 3:18:25 AM EDT
| I've put maybe 300 rounds through my 16 inch middy I built. I have an st-t2 buffer kit and full auto BCM bcg. After only 200 rounds through rifle I started getting a lot of jams. My bolt will hold open but couldn't shoot without a jam after first mag. I give it to my gunsmith and he tells me the gas rings were broken on a brand new bcg. I send it to BCM to fix because that shouldn't happen on a new bcg. They replace it and send it back. Take it to the range and first mag went fine and then it jammed like before but gas rings are fine. Any reason why my gun jams when the gun gets hot? Bad bcg? |
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What barrel is on your rifle?
And what type of jams are you getting? Meaning in more detail or pictures would be nice. And have you tried different types of ammunition in your rifle, if not/so what types have you tried? When you say your bolt will hold open do you mean after firing the last round it will lock back on an empty mag? If so that should eliminate under gassing/weak ammo. |
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Still not for sure what you mean on how it is jamming - there are so many ways it can jam and each has a unique set of causes. From my understanding it isn't jamming on extraction correct? Meaning when it jams there is no fired casings in the rifle, they are already ejected. It is jamming when loading a new round? If so does it try to double feed, or get caught before going into the chamber on something? A picture really is worth 1000 words on these cases.
With a GM barrel I highly doubt it is a gas issue, and with a BCM BCG I really doubt it is an issue with the bolt. But anything is possible. I would check your mags, have you tried using a different magazine to see if the outcome changed? |
| Sorry no pics. The spent case is gettin jammed on the one being loaded in the chamber but it's not stove piping. Round won't chamber. It's not the mags. I've tried multiple. why would it work fine for 30-60 rounds with no issues and then when it gets hot it starts acting up? |
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Sorry no pics. The spent case is gettin jammed on the one being loaded in the chamber but it's not stove piping. Round won't chamber. It's not the mags. I've tried multiple. why would it work fine for 30-60 rounds with no issues and then when it gets hot it starts acting up? So, it's a double feed? |
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So, it's a double feed? Quoted:
Quoted:
Sorry no pics. The spent case is gettin jammed on the one being loaded in the chamber but it's not stove piping. Round won't chamber. It's not the mags. I've tried multiple. why would it work fine for 30-60 rounds with no issues and then when it gets hot it starts acting up? So, it's a double feed? Sounds like failure to eject/extract if I'm reading that right; empty case + fresh round getting jammed up |
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Sounds like failure to eject/extract if I'm reading that right; empty case + fresh round getting jammed up Quoted:
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Sorry no pics. The spent case is gettin jammed on the one being loaded in the chamber but it's not stove piping. Round won't chamber. It's not the mags. I've tried multiple. why would it work fine for 30-60 rounds with no issues and then when it gets hot it starts acting up? So, it's a double feed? Sounds like failure to eject/extract if I'm reading that right; empty case + fresh round getting jammed up Yeah I misread and skipped over the "spent" casing |
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Would taking out the o ring maybe help? Just a guess, but if the extractor claw is coming off the spent rim he probably oughtta leave the o-ring in place (since it provides additional tension). OP, I'd try cleaning the chamber. I'd check extractor tension on the bolt. Is the rim on the spent cartridge damaged (missing a chunk) or is the extractor easily slipping off the case rim? |
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There is some definite marks on the shell casings. What do I do if extractor is causing the problem? this is hard to diagnose without seeing it, but here are a few things I've run into...maybe they're similar to your situation. 1) Do you shoot steel cased ammo? Doing so and then switching to brass can lead to stuck cases. Clean your chamber with a proper chamber brush. 2) It's possible you're overgassed. Might explain the damaged gas rings. That's a barrel problem, not a BCG issue. 3) Have you tried a different bolt? If a different bolt works, we can eliminate the gas system. Then I'd look at replacing the extractor and spring. Kinda frustrating. I think we could fix/identify your problem in a couple hours at the range. ETA2: An extractor claw with the right tension is going to leave some serious marks on the brass case rim when it slips off. It'd be nice if you could post a pic of your spent casing, bolt, and bolt carrier. |
| If when observing the chamber you are seeing a spent case still in there it's an ejection issue. If the rims of the casings are ripping or showing damage it could be a dirty chamber or over gassing. When it is getting the brass out where are they landing on the ground in relation to your shooting position? If it's not shredding the brass it could be a weak or misshapen extractor or a messed up ejector. I agree with starting at trying a different bolt and see if the problem persists. |
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