|
BK1133, I don't think it's the extractor spring on the M4 that's the problem. I think the gas port is a might big.
The bolt and carrier are getting a mighty blast of gas from the gas tube and the whole bolt carrier assembly is getting a boot to the rear -- the centrifugal force of the bolt turning as it unlocks is causing the extractor to literally FLY off the rim, giving failure to eject malfunctions. The little black extractor rubber nub (sorry for nomenclature failure) helps keep the extractor snapped over the case rim.
If the gas port were to be drilled a couple of thousandths smaller or the entire gas system extended out two inches (like Armliate's and Rock River's mid-length gas system) your port pressure will be WAY lower.
|