Has anyone used Norrells Moly resin on a Carbine buffer tube ? I'm wondering if it will wear with the stock movement.

I have done cerakote on them.  It does wear, the inside of the coated metal CAR stocks are rough, but so did the original coating.

Yes. I did Xm colt gray on a Tonys custom uppers aluminum stock buffer tube 7 years ago. Tube is commercial spec and was a very smooth semi gloss black. The stock had a dull gray rough finish almost like it was parked. I used gloss black high temp engine paint on the stock and latch lever and baked in a toaster oven. I degreased and did one coat moly Resin on the buffer tube and baked per instructions.
There’s some streaks in it now revealing the black underneath but it’s not bad enough for me to have pulled it to redo.
If I was going to do it again I would do 2 coats and bake the first one longer. I believe norrells says that this will result in a slightly green tent to the gray like greenish parkerizing. Then I would do a second coat at the normal time/temp.
Putting it on a tube with anodizing may yield better results vs the extremely smooth/slick finish on the Toney’s buffer tube.
It ant museum quality but I’ve been generally pleased with the results considering it’s been 7 years now.
I’ve also done the back end of charging handles too.
Hell maybe I’ll pull it and fallow my own advice.
John44

Yes it will wear on a very slick/smooth finish.  I love the stuff but the surface area must be blasted or porous for best result.  No worries if you or a friend has a blasting cabinet.

I recently coated a KAK 2 position buffer tube with Norrells Colt Gray-Black Flat.  The tube's original anodizing had a distinct green tint to it, which didn't work for me.  Here's a picture of the buffer tube with Molyresin:



I did a light grit blast, but for the most part except for cleaning with brake cleaner, I just applied the Molyresin over the existing anodizing.  This rifle doesn't get a lot of use as it's a display rifle, but the stock has been cycled dozens of times so far and the Molyresin has held up pretty well.  That's a Colt N stock on it, so a metal stock (like the one pictured below) might wear on the finish more.

Here's a pic of an old Essential Arms buffer tube that has been cycled thousands of times (it's nearly 20 years old):



I expect the buffer tube with Molyresin to get a similar wear pattern over time, but I'm okay with that.  If it doesn't hold up as well, I'll just recoat it.