Problem getting "castle nut" off AR

[Dentite]

Hey gang,

I'm wanting to install a single point sling style endplate on a Colt 6920.

I borrowed a nice sturdy AR wrench and a mag block from a friend.

I have completely unstaked all metal from the endplate out of the castle nut. Penetrating oil has been applied and allowed to soak in.

The buffer and spring have been removed.

I don't see anything else holding it up but I can't seem to get the nut backed off. I'm not putting all my strength into it because I'm afraid I might crack/bend the lower reciever. I even gave the end of the wrench a few taps with a hammer but nothing.

Basically I'm being careful and don't want to force anything.

What's next?

More muscle?

Heat?

Thanks guys.

 

[sleepyone]

I've had to give them much more than a few taps with a hammer to break them loose from a factory installation. You need to put more muscle behind it. You aren't going to hurt anything as long as you are using a proper hammer and castle nut wrench. I have used a 16 oz. hard rubber mallet and a brass gunsmithing hammer. Can't remember what it weighed. Just make sure your strikes are solid and that your wrench is firmly in place so it does not move side to side.

 

[adelbridge]

i have used a breaker bar but I am guessing there is still staking where you cant see it. you can always cut the castle nut with a dremel or use a nut splitter (or both)

 

[BBBBill]

Consider the castle nut expendable and cut it off.

 

[PBR Streetgang]

I'd cut it off also. They only cost a few bucks.
But you''re using the wrong tool to get it off. The mag block won't take the strain off the upper receiver.
There is a clamshell unit that solidly wraps around the upper receiver and goes into the vise. It takes the strain off the upper receiver when working on it..............

 

[burrhead]

Castle nut's on the lower receiver.

 

[MasterSergeantA]

You could also try applying just a little heat to it, on the off chance that whoever put it together used Loc-tite or something similar. A torch is best, but even a hair dryer on high can help.

 

[ApacheCoTodd]

Don't snap at me - just checking...

Rightee-tightee-leftee-loosee, right?

Your wrench is going down on the left side of the receiver (shooter's perspective) or up on the right side of the receiver, correct?

Wouldn't be the first guy to try to spin it off the other way - it shouldn't be too hard on a factory Colt.

 

[PBR Streetgang]

My mistake ,CRS is kickin in,,,,,,,,,,read castle but had barrel nut on the brain!!!!!!!! I hate when that happens :banghead:

 

[Dentite]

Thanks for the replies. A new nut is on it's way in the mail. I'm going to leave it alone until I have the new nut so if do have a make a cut or two I can replace it with the new one.

Thanks guys.

 

[hentown]

I'd cut it off also. They only cost a few bucks.
But you''re using the wrong tool to get it off. The mag block won't take the strain off the upper receiver.
There is a clamshell unit that solidly wraps around the upper receiver and goes into the vise. It takes the strain off the upper receiver when working on it............

How in GAWD's name, do you use the clamshell with the lower attached? Inquiring minds want to know!

To the OP: Some companies Loctite the castle nuts. You'll have to apply heat with a propane torch, in order to break the Loctite.

 

[Dentite]

Update:

I got the new castle/receiver extention nut in the mail (along with a new standard endplate in case I decide to ever remove the plate with the sling attachment).

I ended up having to cut off the nut...I was able to cut down just to the threads and break the nut open.

Interestingly enough I also had to cut off the original endplate. During the process of "unstaking" the endplate material out of the castle nut, some of the aluminum was pushed into the threads of the buffer tube. Because the endplate is indexed with an extention of metal that goes into the index in the buffer tube, it wouldn't just slide off.

That was an easy 1 minute fix with a cut off wheel and pliers to open the ring enough to allow it to slide off.

Perhaps that metal getting pushed into the threads was a factor in the castle nut not wanting to budge. Who knows...all I know is I got it done and put back together.

Thanks again for the input.