Just ground around to installing my standard Cam Pin with a PF 308 NP3 Coated Roller Cam Pin in my Aero M5 w/Aero Bolt Carrier and JP Enhanced 308 Bolt.



For starters, the POF Roller Cam pin fits with plenty of room to spare without removing the gas key.

It seems to remove a lot of the grittiness when pulling the bolt carrier group back using the charging handle back.

A lot of the scraping and grittiness you feel when you pull the bolt back with the charging handle is the square end of the cam pin sliding down the
cam pin channel cut into the top of the upper receiver.  Makes sense this would make it a lot smoother.

Yeah, its an interesting design.

I have one on one of my AR15's but haven't shot it yet.  This picture provides some historical context:

Interesting.  Wonder why it never caught on?  I'm guessing it was a a buck more expensive so it was replaced with the standard solid cam pin with a square head.

Even Colt forgot what they had.  The guys that did the engineering on the AR10A were probably long gone by the 1970's.

Why is this a big innovation? Im not well versed on tiny parts.

On the .308 AR10 and similar guns, there can be a lot of rotational torque.  My guess is that they wanted to deal with this using the roller cam.

When POF re-introduced it several years ago, a lot of people were whining about the wear inside the upper receiver where it transitions from the cam pin recess to the track, not that this is even noticeable performance-wise.