Castle Nut...

[068]

How in the world do I remove the thing? Trying to add a sling point but can't get the nut to budge.

[copemech]

AR wrench, they are tight and peened!

[068]

A freaking gorilla must have put that thing on. I used an AR wrench and all I succeeded in doing was rounding off one of the spots that the wrench hooks into.

[MostlyHarmless]

Google "ar-15 remove castle nut" or similar. It's a great big internet out there.

You might find that using a drill or dremel tool to grind out the staking will help. Be prepared to replace the nut and plate afterwards- removing staked parts is not always pretty. Mileage will vary.

Make sure your receiver is adequately held in good vise blocks or similar. Trying to remove staked parts can be a good way to mangle an aluminum receiver if it's not held properly.

[centuryan1]

Could not get mine to move!!! Took it to a guy at a pawn shop it took the both of us to finally get it off