Yep, I'm finally happy with my MCX's new Carriage Assembly!! After 2 February trips to Exeter, a new Upper, plus installing POF's Roller Cam Pin - She ran 90rds of mixed Federal & PMC 5.56 and .223 ammo today - Perfectly!!
We have vertually NO cam path wear, and only a slight line in the alloy finish inside the upper where the Firing Pin Retaining head rubs.
Her bolt locked back on every empty mag for a variety of Magpul and Lancers too.
Here's the Upper's cam path with only SIG's test fire and my manual cycling.
Here's the same Upper's cam path after 90 rounds today.
Here's couple shots of POF's clever Roller Cam Pin's installed. This little trick provides a noticeably smoother action in both this MCX and my SIG516s.
She's not perfect though. The Firing Pin Retaining pin sticks out just enough to make this line mark in the Receiver's finish.
And wears the finish off a small spot on the head of this Retaining pin.
I mentioned my 2 Exeter trips for this rifle's Carriage Assembly recall to our range officers today. They said they've heard that a lot - 2 trips seemed pretty standard. But, I think we're now good to go!!