Superficial receiver extension thread wear?

[praythenspray]

Well, I am a bit pissed at myself. Newb mistakes.

Story,

I have a Wheeler group beam type torque wrench and Armorers tool combo. I bought a BCM intermediate tube kit. I had the QD end plate(from the kit) on my lower and decided to go to just a basic one. So, I unstaked it and then used the Wheeler armorer tool to loosen the castle nut.

Here is where the pathetic newbness kicks in. When using the Wheeler wrench, apparently I was not careful enough and the teeth actually contacted the threads when untorquing the castle nut. Also, when unstaking it, apparently the end plate had some burrs or wasn't the exact shape it was before, so I had to work to get the old end plate off. So after all is said and done, the threads of the receiver extension has some shiny spots. The threads themselves are still functional, just the annodizing has been scrapped off. The castle nut still threads on and off without issue.

I cleaned it up and used Alumi-black on it and it has darkened the areas back up.

I would assume this would be more of an actual issue if it happened with a steel barrel nut and upper receiver threads(possible galvanic corrosion?). So, am I correct in assuming it is fine and just superficial finish wear? I would hate to have to replace the whole tube because of this, it still functions, just has some finish(now doctored) damage.


P.S.
Feel free to laugh at my goof, lord knows to the more experienced out there, this bone-headed mistake might cause a chuckle.
I have since ordered a BCM KMR(and castle nut) wrench. Good night what a difference! I installed everything back together, took one look at that thread marring unwieldy Wheeler wrench and fired that turd across the yard.

[26 Inf]

The support and alignment function for the buffer tube are accomplished by the portion of the tube that is screwed into the lower receiver. The castle nut serves more of a jam nut type purpose to keep the tube from backing out.

You are just fine.

Pick up the wrench, clean it and sell it on ebay.

Good luck.

[tigershilone]

Pretty much what 26 Inf said, if you didn't do severe damage to the threads that are actually in the receiver you will be gtg.

If I recall properly, BCM makes their RE's out of 7075 so they will take the load just fine. That said, I have never seen a failed 6061 alloy RE either, but 7075 is at least a good third stronger than 6061 and is stronger than several low grade mild steels. 6061 is no slouch either, both are vastly superior to the 5000 series alum alloy that most commercial alum parts are made out of.

Just double check for any cracks in the RE, very unlikely in your case. You said the castle nut goes on without issue, so unless you are missing big chunks out of several threads you are ok.

[praythenspray]

Thanks for the replies.

Now, some of the anodizing loss on the threads DID occur on the portions that screw into the lower. The end plate was boogered and I tried my best to remove it gently. So when I said shiny spots i meant over ALL the threads. When I examined it, it was just a loss of anodizing. None of the threads were completely smashed down or bent over. The alumiblack added the black color back to it and like I said, the castle nut screwed on effortlessly as did the tube screwing back into the lowers threads.

On a side question, for whoever with experience who is kind enough to comment. Hypothetically, if one were to have an older used buffer tube and lower that both had threads with anodizing wear that you could see aluminum, would there be any issue in using them and running the firearm? Would those threads not having their anodized coating and being fitted together possibly be a point of failure since they don't have their "protective coating" on them?

[tigershilone]

Are you going to be dunking it in salt water on a regular basis? IF not, then you really don't have any issues. If it bothers you could either paint them or use your alum-black again.

Reality is that if you lube your rifle you will get some lube in these threads from gravity if stowed barrel up and that will also guard against corrosion, or you could apply a light coat of grease when installing the parts together. There isn't a lot of chance of dissimilar corrosion to happen here as they are both aluminum. Assemble them and go forth with confidence.