Slosolo2
Here to be happy
A friend has a 300blk pistol that isn't cycling more than 2 rounds before failure.
Not sure what length barrel, more than 8 less than 10. H2 buffer. No suppressor. A2 flash hider.
Went to the range today and did some testing. Started by firing 5 sub and 5 supersonic from my gun to confirm function then fired the suspect gun to confirm it still had a problem. It failed to eject on first round mangling a brand new casing.
We then swapped uppers between the lowers.
Fired 5 of each type through the suspect gun lower with my upper without malfunction.
Suspect upper on my lower didn't go well.
Supersonic
First round ford and cycled correctly
2nd round fired but 3rd round failed to feed as in it was still in the magazine so third trigger pull was click no bang.
Subsonic
First round failed to eject and 2nd round was stripped from mag. Both the spent and unfired round tried to enter the chamber. They were jammed but easily dislodged.
Took it home and squirted wd40 through the gas tube whole looking down the barrel. First squirt nothing came out but the second squirt did and it seemed to push a clump of something out. Note this gun has less than 30 rounds through it total. Upper was purchased fully assembled from the oem.
Ran a patch but didn't get a clump just the usual carbon.
Pulled the handguard.
Gas block looked to be properly aligned.
Pulled the gas block but not flag hider.
Barrel hole is unobstructed.
Didn't un-pin the tube.
Checked the bolt for proper function. It stands up without collapsing but is easy to push down. I did suggest he disassemble and check to ensure it's built correctly and lube it generously.
My thoughts are that it needs more gas or less buffer.
My fear is the upper is not machined square and binding the bolt. Is that even possible?
Anyone have suggestions or insights on further testing or what might be wrong with it?
Not sure what length barrel, more than 8 less than 10. H2 buffer. No suppressor. A2 flash hider.
Went to the range today and did some testing. Started by firing 5 sub and 5 supersonic from my gun to confirm function then fired the suspect gun to confirm it still had a problem. It failed to eject on first round mangling a brand new casing.
We then swapped uppers between the lowers.
Fired 5 of each type through the suspect gun lower with my upper without malfunction.
Suspect upper on my lower didn't go well.
Supersonic
First round ford and cycled correctly
2nd round fired but 3rd round failed to feed as in it was still in the magazine so third trigger pull was click no bang.
Subsonic
First round failed to eject and 2nd round was stripped from mag. Both the spent and unfired round tried to enter the chamber. They were jammed but easily dislodged.
Took it home and squirted wd40 through the gas tube whole looking down the barrel. First squirt nothing came out but the second squirt did and it seemed to push a clump of something out. Note this gun has less than 30 rounds through it total. Upper was purchased fully assembled from the oem.
Ran a patch but didn't get a clump just the usual carbon.
Pulled the handguard.
Gas block looked to be properly aligned.
Pulled the gas block but not flag hider.
Barrel hole is unobstructed.
Didn't un-pin the tube.
Checked the bolt for proper function. It stands up without collapsing but is easy to push down. I did suggest he disassemble and check to ensure it's built correctly and lube it generously.
My thoughts are that it needs more gas or less buffer.
My fear is the upper is not machined square and binding the bolt. Is that even possible?
Anyone have suggestions or insights on further testing or what might be wrong with it?