I ordered a super duty Geissele complete upper . The rail and upper receiver have a key lock tab for anti rotation purposes. Being a lefty I don’t like upper receivers with forward assists. I’m going to have a gunsmith replace the factory Geissele upper with a vltor mur upper (no fa). He’s going to machine a recess into the vltor mur upper for the rail to lock into it with the key tab. He said the upper receiver part that will be cut will be bare aluminum. He said he uses alumablack. Should I go that route or have it sent of to someone to be cerakoted? I just want it refinished in a plain black color.

Would doing this to a vltor mur upper
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Yeah, it might just be the edges that may not be perfect.

@snackgunner

What rail is on that upper?

If it has those 2 locating ears on the bottom also, it's not going to fit on an MUR without further modification....

Anderson and Aero both make slick side uppers, and would probably cost less than the machine work you want to have done.
I have used both, and they are good to go.

Mk16 superduty rail 10”

Except the machine work needed is machining the indexing notch on the top of the receiver. So the machine work would be the same regardless of which upper is used.

Ok, I misunderstood where the tabs were.

Disregard:: FirePyro answered the question

@snackgunner

So, I tried to put a G rail on my Noveske/MUR upper and those two lower locating ears would not fit over the receiver.

I ended up getting a MilSpec slick side upper to use and that worked fine.

Your upper receiver may be different. But, check the width at the bottom front to be sure.

Was it a older version of the vltor mur? I think the older ones had problems with the geissele rails but not the newer ones

Can anyone confirm what mcw is talking about?

Also I don’t believe the superduty mk16 rails have tabs on the side

Which geissele rail was it that you tried putting on your mur upper? @mcw