DPMS upper rusting

[Guns308]

So I bought a used AR that had this DPMS 60624 upper and the stainless barrel has some rust staining, not really pitted at all. The aluminum handguard has steel threaded inserts that are rusting pretty heavily. What is the best way to clean both parts, and how does the handguard remove?

https://www.opticsplanet.com/dpms-tpr-a3-20in-5-56mm-upper-receiver-assemby-barrel.html

 

[deemus]

handguard should have some allen screws on bottom and / or side.

No help on how to get rid of it.

 

[zackmars]

Brass brushes work the best, once you get it as clean as you wanted, either have it refinished or use something like hornandy one shot or boeshield t9 on it and keep an eye on it.

I believe the rail is threaded on the nut, and there's a "lock washer" that butts up against the rail.

Personally, I'd get a different rail. By the time you send the nut off to be refinished (assuming you go that route), you're well over halfway to a BCM MCMR or something

 

[popper]

Kroil and then CLR.