Originally Posted By BravoCompanyUSA:
Originally Posted By Winn:
Additionally, a specific question for Paul ...
Which "combination" do YOU suggest/recommend for use in your 16" midlength uppers, as opposed to your 14.5" carbines?
IOW, for the 16" mid would you suggest … your BCM:
5 coil spring + black insert + O ring (the "full boat")
5 coil spring + black insert, but no
(or perhaps some “other” configuration for a 16" mid ... not sure what that would be though)
I always believe there is more than one way to skin a cat. Therefore there are a variety of different extractor set ups working well for the shooter.
We have seen too much tension exhibit itself in the form of not fitting over the rim of the casing (and not feeding). We have also see it where it fits over the rim of the casing, but upon the ejection part of the cycle, the grip is so strong that it fails to eject. And once we saw a very strong extraction system work ok when everything was clean, but after high round counts and having a bolt gunked up, the extractor moved less freely, resulting in new extraction issues.
If using a BCM extractor spring, I have not found a carbine that “needed” the o-ring to increase extraction power and run properly. However, it has been theorized that the o-rings may offer additional assistance in extractor float issues.
Whichever way you set up the BCM spring, o-ring, BCM (“real deal”) black extractor buffer, we have yet to see a circumstance where it could not fix extractor tension issues.
16” middys will require less extractor tension to run properly than a 14.5” would.
On a 16” middy, we run a standard CAR buffer or H. (for auto, we run H)
On a 14.5”, we run a H or H2 (for auto, we run H2)
For me personally I just run the BCM spring and BCM black buffer insert in my BCGs. It has been 100% in the MK18s, BCM 11.5”, M4’s, Middys, and Rifle systems.
Hope this info helps,