Re: POF roller cam pin
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: KevinB-KAC</div><div class="ubbcode-body"><span style="color: #FF0000">In DI guns with extraction, the bolt is pressurized against the barrel extension. In piston guns this does not happen and the piston rockets everything to the rear, so the delays on the bolt unlocking do not occur, and the can pin tends to tear a larger trough in the upper than DI guns (high round count DI guns will show this too).</span>
Hence the roller cam pins, and the rounded corner cam pins etc. Remember the DI cam pin is only square so you can get it aligned while under the gas key, so its a legacy part on a piston system </div></div>
This is good information and falls basically along the lines I was trying to explain in my earlier post. However, I fail to see how the "delay" has any bearing on the force with which the cam pin travels. The BCG is still "rocketing" back, which still forces the Cam pin along its slot... in a hurry. From what I've experienced, and I probably spent more time than I should have on this, it's the tension of the bolt inside the BCG created by the gas rings that causes a "softer", if you will, movement of the cam pin in a DI gun. I'd venture to guess that if you left the gas-rings on the bolt in a Piston gun the gouge would not appear as quickly. Might even act just like a DI gun with regard to this.
Oh, and by the way, I DO think the roller Cam-pin is a Great thing and should be standard on ALL AR's.