ok, plug up the muzzle and chamber then try again. If there isnt any loss of pressure we are left with the bcg and its mating surface with the gas tube, which looked fine in the pic.
do you remember what the barrel port size was when you measured it?
No loss. Put 2 latex gloves over the end (don't laugh, it's all I could find) and blew them up. They held the air until I let it out.
Around .075-ish.
Around .075-ish.
Im not laughing! that was a good idea. sounds like the system thus far is solid. The port may be on the smaller side of what I have experienced; I think mine was .077 new, but that shouldnt be that big of a difference.
let me recheck that, be back quick
let me recheck that, be back quick
yep, .077. so far so good.
with it back together, how far into the upper receiver does the gas tube protrude?
with it back together, how far into the upper receiver does the gas tube protrude?
about half way into the carrier key cutout in the upper?
do you have an air compressor?
do you have an air compressor?
thats where it should be for sure. Dont worry about the compressor, it wasnt that important. Since the bcg is from bcm and new, it should certainly pass a gas ring test. Am I correct to assume the gas key is solid and no evidence of leakage around the interface of the bcg body and key?
does the gas tube to bcg gas key interface line up and seems tight?
If that checks out we have eliminated the gas system as a problem as far as I know. That just leaves the buffer and spring. Fortunately they are the easiest to check. Do you have another carbine spring and a carbine buffer?
does the gas tube to bcg gas key interface line up and seems tight?
If that checks out we have eliminated the gas system as a problem as far as I know. That just leaves the buffer and spring. Fortunately they are the easiest to check. Do you have another carbine spring and a carbine buffer?
