Purchased these PWS ratcheting castle nut from Joeboboutfitters and received horrible customers service from them when I tried to call and talked to their VP regarding my problem. Not only was the gentleman rude and not willing to help he insisted it is my install error, and that they would not allow me to return the multiple ones I purchased and that I need to contact the manufacturer and basically blew me off. I stated I will be contacting my credit card company and they cancelled my account… I never had a problem with previous orders but it seems if a problem does occur this company will not take care of the customer. With many high quality ar15 part distributors out there that I have dealt with and will solve customer issues. I would not recommend Joe Bob Outfitters.
The receiver extension and how it mounts to the receiver is already a weak point on the ar15, I have seen people use 2 endplates to extend the contact area of the endplate nipple and the thread where they engage to stop the buffer tube from rotating. When the castle nut is properly torqued the buffer tube and endplate should not rotate, however under hard use with enough rotation force on the stock (counter-clockwise from the top) you can cause a non field reparable malfunction to the buffer tube and rotate it out of receiver. rare but still happens.
PSG 612 now available: https://goo.gl/dDMYNQ
This video shows a basic technique for squaring 6 sides on a steel block using the Tormach PSG 612 semi-automatic surface grinder. Block is hardened to 52HRc.
Click the link above for more information!