I recently finished building a 300 blackout and after cycling 3-4 rounds it wants to jam to the point I have to force the bolt back. First I thought it may be bad head spacing but swapped out another BCH and it functioned fine, I know BCH aren't very expensive but I was curios if there was something to look at with the one I have to figure were it may be causing my issue before I do purchase another.
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malfunctioning BCH
- Thread starter GunNut365
- Start date
tango1niner
New member
Let the games begin...
"...swapped out another BCH..." Another BCH what?(whatever a 'BCH' is.) If you just changed the bolt you may, and probably have, created bad headspace. Bolts are not interchangeable.
"...have to force the bolt back..." A failure to extract is an indicator of bad headspace, but that's not the only cause of extraction issues. You assemble the barrel and receiver using proper headspace gauges or just screw the barrel in and hope?
"...have to force the bolt back..." A failure to extract is an indicator of bad headspace, but that's not the only cause of extraction issues. You assemble the barrel and receiver using proper headspace gauges or just screw the barrel in and hope?
My opinion is your cam pin is galled and binding in it's track due to lack of lubrication.
"If you just changed the bolt you may, and probably have, created bad headspace. Bolts are not interchangeable."
Referring to an AR 15: Headspace of a low round count bolt and barrel extension most likely will not be adversely affected by exchange of another low round count bolt. I know this is counter to all the stuff we've heard BUT it's common practice for military units to dunk a handful of bolts/carriers in a tub of solvent or diesel before cleaning. After cleaning, the bolts/carriers go back in whichever rifle is being re-assembled next.
I don't do it that way but apparently it's not such a big deal.
"If you just changed the bolt you may, and probably have, created bad headspace. Bolts are not interchangeable."
Referring to an AR 15: Headspace of a low round count bolt and barrel extension most likely will not be adversely affected by exchange of another low round count bolt. I know this is counter to all the stuff we've heard BUT it's common practice for military units to dunk a handful of bolts/carriers in a tub of solvent or diesel before cleaning. After cleaning, the bolts/carriers go back in whichever rifle is being re-assembled next.
I don't do it that way but apparently it's not such a big deal.
arquebus357
New member
How provincial. OP thinks everyone knows the acronyms he and his friends use when texting. hahahahaha.
An example of "provincialism" .... A guy from Spirit Lake, Iowa walks into a Brooklyn, NY Italian deli and orders a "vinny's big dago sub".
An example of "provincialism" .... A guy from Spirit Lake, Iowa walks into a Brooklyn, NY Italian deli and orders a "vinny's big dago sub".
Take the bolt carrier group out and grease (not oil) the cam pin and the backs of the 7 bolt lugs. Shoot 5 rounds and grease the backs of the bolt lugs again. Shoot 10 rounds and oil the bolt so it is sloppy wet. An AR-15 bolt carrier group may need to run wet with oil until it breaks in. Once broken in, you can back off on the amount of oil.
"Take the bolt carrier group out and grease (not oil) the cam pin and the backs of the 7 bolt lugs. Shoot 5 rounds and grease the backs of the bolt lugs again. Shoot 10 rounds and oil the bolt so it is sloppy wet. An AR-15 bolt carrier group may need to run wet with oil until it breaks in. Once broken in, you can back off on the amount of oil."
Yupper. Oil oozing out of every hole and smoking like it's on fire for the first 10-20 shots. That's the way I do it. No joking, it works.
Yupper. Oil oozing out of every hole and smoking like it's on fire for the first 10-20 shots. That's the way I do it. No joking, it works.
tango1niner
New member
Maybe he meant to type "BCG" = bolt carrier group...
The "g" and "h" are right next to each other on the keyboard...
The "g" and "h" are right next to each other on the keyboard...
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