I have been trying to get a friends BCM 11.5 to calm down for lack of a better term. It is what I thought to be way over-gassed. I installed an adjustable gas block, fresh carbine spring, Sprinco blue spring, carbine, H, H2 and H3 buffers and the buffer still smacks the receiver extension during recoil. It is one of their assembled uppers with the standard profile BFH barrel and BCG. No matter what I have tried the thing just seems to have a "harsh" recoil for a 5.56 AR platform. It feels like an old blowback Colt 9mm carbine I shot years ago instead of a regular DI AR.
I checked the carrier travel to make sure its not hitting the receiver. No issue there either. Tried different types of ammo including some lighter handloads I made for it. The lighter loads helped but he wants to run 556 since that is what he uses in his other rifles.
I was able to get the ejection pattern to change from about 1:00-2:00/2:30 with the buffer/spring change and the gas adjusted to just barely reliable. I have assembled several uppers for myself and friends and all of them run great or need some slight tuning, but this one is just angry for some reason.
I have not tried an A5 extension and buffer yet. I was hoping someone here might have been through an issue like this and have some insight. Or maybe point me in the right direction as to what I could check that I might have missed.
I checked the carrier travel to make sure its not hitting the receiver. No issue there either. Tried different types of ammo including some lighter handloads I made for it. The lighter loads helped but he wants to run 556 since that is what he uses in his other rifles.
I was able to get the ejection pattern to change from about 1:00-2:00/2:30 with the buffer/spring change and the gas adjusted to just barely reliable. I have assembled several uppers for myself and friends and all of them run great or need some slight tuning, but this one is just angry for some reason.
I have not tried an A5 extension and buffer yet. I was hoping someone here might have been through an issue like this and have some insight. Or maybe point me in the right direction as to what I could check that I might have missed.