Castle nut on stock question...

[PSP-Ret]

I just removed my Castle nut on my S&W M&P 15 PSX and it was staked and it was a bast^%^%&d to get off since I didn't have a wrench. I did it by tapping inside each notch with a drift punch and hammer. Didn't ding it up too much and what I did mark I filed out and blackened it so you can't really tell. Will get a new one if I feel like it later. I did that to put on a single point sling plate for my carry strap.

My question is why do you think they have staked. What on earth can happen. I just put on some loc-tight on it and its good to go. Not the permanant kind the other.
Why does the factory feel that needs to be staked...your opinions please.

 

[Dragon88]

S&W is not the only manufacturer that stakes the castle nut. Any quality manufacturer will, and all milspec carbines will have it staked. The castle nut can back out under use. Friction is the only thing holding it tight unless you stake it.

Loctite is an incorrect means of securing the castle nut.

 

[PSP-Ret]

Why is loc-tight an incorrect way of securing the nut????
Not being smart just trying to learn. All the recoil and movement is straight back, so how does it come lose so easy. Don't understand

 

[Dragon88]

The castle nut and receiver end plate are steel. The buffer tube is aluminum. Using loctite, you will need to apply a lot of force to remove the castle nut in the future, which can damage the relatively weak aluminum threads on the buffer tube. If it gets really stuck, you may want to hit it with heat to soften the loctite, which again can damage the buffer tube.

Staking the castle nut will deform a small amount of steel into the cutouts on the steel castle nut, securing it very well. Removing it in the future will require dremeling and possibly destroying the least expensive part of the equation and put minimal stress on the softer aluminum buffer tube. If you look at different manufacturers, DPMS, which is known for being one of the lowest quality, uses loctite on the castle nut because it's fast and cheap. Pick up any milspec carbine that passes "the chart" and it will have a staked castle nut.

Some guys will just crank down really hard on the castle nut and not stake or use loctite. That's an option, but you are putting a lot of torque on that aluminum buffer tube, and the castle nut will still probably come loose. A loose castle nut doesn't seem like a possibility until you are at the range and your buffer tube and stock are flopping around.

Sorry that was long. You already used loctite, that's fine it will work. Just realize it may become a hassle in the future if you decide to change something in that setup.

 

[akviper]

What Dragon88 said. If you shoot it a bunch and the nut is not properly staked it will back off and allow the stock to rotate and possibly tie up the gun. All castle nuts should be properly torqued and staked. I have seen several guns come loose in carbine classes. One major brand of AR does not stake their castle nuts and attempts to go the lok-tite route. I personally witnessed six of their guns break loose in a class a few years ago. At best your stock will rotate off center and if it moves enough the buffer retainer pin and spring can escape totally binding the gun. Take the extra few minutes to mount your stock right and the rifle will not let you down.

Go to M4carbine.net or AR15.com for instruction on proper torque and staking of your rifle. Both sites have excellent guides for complete disassembly and assembly. Good luck and have fun with your gun.

 

[CAL.ADAM]

The castle nut and receiver end plate are steel. The buffer tube is aluminum. Using loctite, you will need to apply a lot of force to remove the castle nut in the future, which can damage the relatively weak aluminum threads on the buffer tube. If it gets really stuck, you may want to hit it with heat to soften the loctite, which again can damage the buffer tube.

Staking the castle nut will deform a small amount of steel into the cutouts on the steel castle nut, securing it very well. Removing it in the future will require dremeling and possibly destroying the least expensive part of the equation and put minimal stress on the softer aluminum buffer tube. If you look at different manufacturers, DPMS, which is known for being one of the lowest quality, uses loctite on the castle nut because it's fast and cheap. Pick up any milspec carbine that passes "the chart" and it will have a staked castle nut.

Some guys will just crank down really hard on the castle nut and not stake or use loctite. That's an option, but you are putting a lot of torque on that aluminum buffer tube, and the castle nut will still probably come loose. A loose castle nut doesn't seem like a possibility until you are at the range and your buffer tube and stock are flopping around.

Sorry that was long. You already used loctite, that's fine it will work. Just realize it may become a hassle in the future if you decide to change something in that setup.

plus that 10 folds