Originally Posted by
armatac
I can't tell what you are referring to,
(feeding)
If you are pushing on the bolt, and pushin on the back of the carrier,(which all AR types do) The cam pin is biased by the inside of the receiver to not allow the bolt to rotate. fact
This is a sliding friction, the part sliding is the lengthways stretch of the cam pin, Friction = coefficient of dynamic frictionXNormal load (normal load is a function of main spring, and cam path),
If you had a pure roller, there isn't really a friction loss in relation to the force supplied by the main spring.
Bearing vs. Bushing