Stakes...

Ash Hess

Ask Me About My M14.
Staff member
Moderator
#1
It has long been the standard to have a castle nut staked. Twice. About a year ago when I started at Knight's one of the first things I noticed was no staking on the endplate. I channeled Will Larson for a minute and asked why. The answer was "we don't need it. Torque to 35 and run with it"
Then as I started getting to know the parts I understood why.
First, you have to understand what causes the nut to work loose in the first place. The receiver extension threads into the receiver and isn't held by anything but the end plate and the castle nut.
Now, pick up any endplate you have. Unless it is the old Magpul ASAP plate or a KAC end plate you will notice that where the endplate engages the extention is smaller than the slot on the extension. This allows the extension to rock back and forth. You will also notice that the nub that goes into the lower receiver is smaller than the hole in the receiver. This also allows the endplate, which is designed to fit every AR receiver, to wiggle slightly.
Combined, there is enough movement to break the torque on the nut, resulting in a loose extension if not staked.
Now, Knights machines the receiver forgings in-house meaning we cut the hole in the back of the receiver. We also build our endplates. The process accounts for the thickness of coatings and the fit of the two pieces is very tight eliminating part of the movement I spoke about.
Now the endplate isn't cut for universal fit. it is designed and machined to work with our receiver extensions and our lowers. Instead of a nub that will fit whatever extension you may have we have a roll pin that is very tight in the slot on the extension. When you install our parts onto our receiver, the extension doesn't rotate even prior to torquing the nut. The roll pin does not get hammered into the extension. It is just installed into the endplate.
This is the "formula" that allows KAC to not stake.
No, there is no locktite either.
There was a huge thread on this on my personal facebook you might have seen. In that thread, someone told me I was intellectually dishonest. Well, I challenge those that feel that way to get some Knight's parts, get the calipers out and prove me wrong.
I can also assure you that if there was an issue with any of the thousands of KAC rifles out there, C. Reed Knight, Jr would have no problem having an endplate and nut that allowed for staking made and put on our rifles.
I will caveat by saying that I DO NOT recommend this route with non KAC parts and as I stated above, I am a disciple of Semper Paratus Arms and if you have the ability, Stake.
If you are the proud owner of a KAC, do not fret over no stakes.
 

nate89

NateMac
Staff member
Moderator
#3
Good explanation on the reasoning behind the no staking. I'll be honest after Will's class I started noticing things like staking jobs, and also noticed they were conspicuously absent from the KAC guns that I thought were some of the best guns out there. I had heard some basic thoughts on the reasoning why they were not staked, but this is a much more detailed and logical explanation, and helps it make more sense for me.
 
#4
Interesting information, especially about the clearance allowing for movement. Years ago, I took apart an Olympic arms carbine. The castle nut and extension had been drown in red locktite from the factory. That was a horrible endeavor...
Another example of how quality wins over "bandaids".