Forget what you just read on Reddit and Facebook. There are plenty of wrong ways to stake an AR-15’s castle nut. Then there’s Caleb’s Way, which he’s going to demonstrate for us today. The castle nut threads onto the receiver extension (aka buffer tube) and locks the extension to the receiver. It’s called a “castle nut” because of the evenly spaced wrench notches that make it look like the top of a medieval castle’s tower. You stake the castle nut to the receiver endplate to prevent it from backing out, which in turn prevents the receiver extension from working loose.
Caleb demonstrates with a Geissele buffer tube, Bravo Company endplate, and a Forward Controls Design Castle Nut FCD. You’ll need a bench vise, lower receiver vise block, cross-peen hammer, and a center punch – pointed tip or square tip is fine. Do not use a woodworker’s countersink punch! Before he begins, Caleb shows us an example of how NOT to stake the castle nut: too shallow, with mere surface damage to the nut and endplate. You’ve gotta move some metal to do a proper staking job!
There are three small, shallow notches on the side of the castle nut that faces the rear of the receiver. Position the punch with its tip covering about half the depth of the endplate directly opposite a notch. Hold the punch so it stands straight out from the side of the endplate – don’t angle it. Lightly tap it several times with the hammer to start making an indent in the endplate. Once you’ve made a nice indent to keep the tip of the punch from slipping, you can apply harder hammer strikes, but DO NOT whale on it!
When you’re done, you should have a neat, circular dimple in the endplate, with a good bit of metal smooshed (technical term) into the notch in the castle nut. For an extra-secure installation, stake one of the other two notches in the castle nut. (You don’t have to do all three.) That castle nut is NOT coming loose without your help!
Is staking really necessary? Find out in our earlier video “Smyth Busters: Does an AR-15 Castle Nut Have To Be Staked?”
Get the details on FCD’s upgraded castle nut: “Product Spotlight: Forward Controls CNF Castle Nut”
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Thank you!!!! I wish you had this video out two years ago when I thought it was a great idea to loctite my castle nut.
Just use an automatic punch
Nice info Caleb! But………… you didn't say how to get it off if need be. That "next guy" thing you mentioned.
what if your castle nut doesn't have the cutouts?
What's brands you using because I thought about getting a POW the ratcheting castle nut
Where can I get that nice multiple Dewey rod wall mount?
AR guy 1: "You staked your castle nut wrong."
AR guy 2: "Actually I didn't stake my castle nut at all."
AR guy 1: "We can't be friends anymore."
G3 guy 1: "I use a $400 form and a custom hydraulic press head to manufacture my receivers essentially from scratch."
G3 guy 2: "I use a piece of Unistrut I took home from work, a couple C-clamps, a pair of bolts and wing nuts and a chunk of 3/4" rebar to bend my flats, and I do my welding with a flux-core wire welder."
G3 guy 1: "That sounds like a lot of work and it's cool that you were that inventive with your process using such basic materials. We should get a beer after we're done shooting our superior roller-delayed battle rifles that do not unscrew themselves in use."
I found that I have to clamp the buffer tube in barrel clamps to keep the lower from bouncing around, creating a moving target.
I always wondered how that works, my castle nut does not have those additional gaps. I guess I have to change that nut and then get it staked.
Great, now there’s going to be 100 more “how’s my steak 🥩” posts on r/ar15
My center punch is bright silver with a red rubber palm grip. Is this the incorrect one?
Staking is too similar to pinning and pinning is a California thing. Just keep tightening you castle nut until it doesn't get loose again.
I take my stuff apart way too much to stake anything I am not going to toss and replace. I use ratching ones or just dont stake it. A rifle I am hiking miles with and need to bet my life on is one I would stake, but again, that rifle at that point is a disposable tool in its entirety.
Caleb, always appreciate your expert demonstrations.
I’v definitely been doing mine wrong because i like to use a automatic center punch.
Stake 3 spots for the most tactical positioning.
I'm curious – why not use blue Loctite? Especiaally if you are prone to make changes?
Why is loctite a no go? Genuine question
And knowing is half the battle….
Thanks this always the biggest pain.
Excellent video! 👍🏻
Good Video/Info. THAT'S HOW MINE LOOK!!!!!
Where can I find Caleb's credentials? Just want to know the background of his expertise. Thanks
Going to do this for an old lower I never bothered to stake. Also, love you guys – I called the tech line with a very specific question about installing a muzzle device on my BRN-180S, and got someone helpful in like 5 minutes. Thanks for providing that service.
When he says that his way is the correct way, I believe him.
Is it necessary to apply a coating of any sort to the bare metal in the stake itself? It seems the punch removes any phosphate coating the end plate had. I might be guilty of overthinking things.
Ratcheting castle nuts > everything else
There is no reason to stake the nut at all, stupidity reaches all time high, just like you do not need a forward assist
I stalked mine twice. After watching how little it took to break loose a stake even after being properly staked. I used one of my smaller masons chisels and hammer. The many coats of paint help hold mine too. lol.
Good. Now, how do you correctly remove a properly staked castle nut?
Why bother staking it when a drop of green Loctite will hold it well and not deform any of the metal parts? I mean, its the 21st century after all. Just say'n. It's not 1975 anymore.
Without "close ups" of the castle nut, it is very difficult to see what you are talking about. Good thing I already know!
The best instructional content never makes assumptions about the audience's level of knowledge/understanding, and explains each item, defines all terms, doesn't skip steps or take bits of knowledge along the way for granted.
Videos like this are a great help to people and much needed to ensure people are getting the correct reference material.
ok ok so what shirt do you got on, that color scheme is clean
Automatic punch, no hammer needed. 👍
Don't forget to refinish it with Birchwood Casey Perma-Blue. Or else you'll get rust.
Please make a video of how to take a staked castlenut off.
Why is it bad to use thread locker? I am planning on upgrading my buffer and tube with an expensive one so I didn't stake it yet, it's really the only cheap part on this build. I did use some thread locker and nothing bad has happened yet. I'm sure it will be easier to remove than a staked castle nut.