I would like to install a Magpul ASAP on my Colt carbine.
But I have noticed that the Locking Nut appears peened.
Would I be able to install the sling attachment or does someone with gunsmithing skills need to do it?
got a castle nut wrench? just gotta man through it.
You can do it yourself. You need to buy a castle nut wrench, Brownells is an excellent place to start. Be advised, It’s gonna take a shit ton of tourqe to break the staking. Start by placing the lower in a padded vice. Next, attach the wrench and slide a steel pipe over the handle for more leverage, then pound on it with a hammer. Let me know how it turns out.
start by placing the receiver extension in a padded vise… leather works good. you don’t want to smash your lower in the vise, nor is it ever a good idea to put that much torque on the magwell.
Good point. When I worked on mine I was very careful as to put just enough pressure on the lower to keep it in place, though I never thought about the amount of tourqe that would be excerted on the magwell. She still works flawlessly, so I guess I got lucky. Anyways, thanks for correcting me. I definately wouldn’t want to be responsible for fucking up this gentlemans rifle.
If you have a small punch you can peen some of the metal back away from the castle nut. Then you would not have to use as much force to loosen it.
I would actually use the upper receiver vise blocks rather than put the lower receiver extension in a vise, padded or not.
esplain, por favor
I’m confused also. Doesn’t the upper have to be seperated from the lower to use the upper receiver blocks? Que no?
Hello all, He’s right with a small round steel punch drive the indented metal back onto the receiver tube lock. If you are prone to slipping then put a couple of raps of tape around the area to protect it from tool marks .DON’T get in a hurry and it will be a lot easier to remove the nut. If you are going to do many other modifications to your weapon then buy a good quality armors wrench . DPMS makes one and brownells sells others to. THE no.1 rule in gunsmithing is to take your time and be careful its all pretty simple. 
Patriot
If I were to clamp the RE down, I’d worry that I was transferring all the rotational force to the RE plate tang which could damage the plate (meh, it should probably be replaced anyway after it was staked once), the slot in the RE (bad) or the plate recess on the back of the lower (way mo bad).
IMO the best way to remove it strictly using grunt would be to retain it at the plate, but I don’t know of a way to do that. So, if I were trying to do this I think I’d try the punch method first to reduce the torque needed.
negative.
Damn, you’re wordy. 
Care to expand on that? What do I have wrong?
Thanks for agreeing with me, but be careful because in a forum of clones having a different or fresh view is not always welcome. I will quote one distinguished member here who responded to another of my posts where my experience/opinion differed from the norm.
I guess it is not enough to just evaluate and decide if you agree or disagree.
clamping the receiver extension itself is the only method that totally prevents the situation you’re attributing to it. by clamping the RE, preventing it from moving at all, ALL of the forces are between nut and screw only.
Yeah, about that. I guess I should have slept longer before posting. I have used the barrel blocks as well as the standard magwell block w/o any issues.
that’s pretty unfair. you’re not only taking that completely out of context, but apparently dont even understand the original context.
grudge much?
I’d agree with this if the castle nut were Loctited to the RE, but staking immobilizes the castle nut to the plate. How would clamping the RE minimize sheer forces here?
ah, i see what you’re saying. the index button on the end-plate will keep it from torquing out. but this isn’t increased just by clamping the RE.
No grudge, just my warped sense of humor. Funny part is, I agree with most of your posts.