So, this is a home build. Aero M5 receivers, BCM 762 handle. Barrel torqued with an action rod - i did not use a clamshell.

I took it to the range for the first time and it ate 3 mags in a row no problem. Mechanically it functions just perfect. But i noticed a ton of wear inside the upper where the handle rides back and fourth when you rack it. I think i've racked this thing ~50 times since owning (just playing with it really). The right hand side of the upper (2nd pic) is so deep that it feels almost jagged! As in you could cut your finger. Yes, i put oil on the handle, though i shouldn't have to in the first place.

Handle looks brand new surprisingly, there's zero wear on it at all.

Anyone have any ideas on this? Did the process of me having it baked for cerakote end up ruining the anodizing on the inside? Or defect? Ive never had an upper do this. Im literally at beyond-bare metal and ive only cycled the handle <50 times. Again, barrel was torqued with an action rod, the upper is not twisted - unless it was fucked from the factory that is.


TOP side




LEFT side of upper (jagged edge that literally will cut you):





For those curious:

That's a great question. I have a very similar experience recently with my Aero Precision upper in .308 with the BCM charging handle. I was having some failure to feed issues that I wondered if they were related, they were not. Now I have against my initial leanings spread the Aero shell armorer's grease like peanut butter all over the inside of the upper, exterior of the BCG and all over the charging handle. After about 100 rounds downrange, I have cleaned it all up and now just use CLP. It appears to have resolved the issue. I'm going out on a limb to guess it was a case where all moving parts had to wear in to each other?  I really can't say other than that because that is just one guy's experience with this issue.

Wow... that wear is definitely excessive. Have you tried a different CH to compare to? I've read reports that the M5 upper does not like BCM CH's (in those reports, people said they switched to Raptor's and those worked fine). Maybe try a Raptor or SI?

Here's another thread on the same issue:
http://www.ar15.com/forums/t_3_121/666009_Aero_Precision_M5_receiver_and_BCM_charging_handles.html

Ugh, i would be mad if i had to switch. God i payed like $50 for this damn thing.

Im considering it right now though. I do know that i tried out a standard CH and it wouldn't even close! But i've heard this to be an issue on most M5s (hence why i bought the BCM).

Im already thinking about having this completely stripped and re-coated. This time on the inside too.



I have one upper with thousands of rounds through it that was cerakoted inside too, and there's literally zero handle or bcg wear on it. Its ridiculous how durable properly applied cerakote is.

You are being kinda ridiculous with this.  Kinda laughing at thought of redoing coating. Its simple, known issue with m5 uppers and bcm ch.  Get a new one....problem solved.

If, dimensionally, that CH is digging into the upper... any coating will be worthless. Instead of cerakoting the interior, I'd opt for either:

A) get a different CH (easiest/fastest solution). As mentioned, SI and Raptors seem to work well in the M5 uppers. Not sure about GA SNACH, maybe try that one too? Perhaps take it to a gun store and politely ask to try others that may be in rifles on the rack (I'm sure they won't open new packages for you)?
Or...
B) modify your BCM to fit properly (people have claimed you need to file/grind down the nubs and lower handle portion for it to fit (it's simply, dimensionally, too tight to work properly in that upper).

If you coat it, that CH will just eat through the coating just like it did to the hard anodizing.
Just my .02

My handle already closes perfect, and it isn't tight at all - its actually loose. This isnt an issue with the latch. Its an issue with too much lateral play. Grinding it down will only make it that much worse.

Its only on the left side and top, the right hand side has zero wear anywhere. To me this means twisted upper or its not straight.

Ill go buy a raptor, but dont see how it will fix anything as this is not an issue with my latch not closing.