Home / Parts / Buffer Tubes and Kits / Toxic Mil-Spec Steel castle nut “Toxic Mil-Spec buffer tube (6 Position)” has been added to your cart. View cartContinue shopping Toxic Mil-Spec Steel castle nut$395 Toxic Mil-Spec Steel castle nut quantity Add to cart Category: Buffer Tubes and Kits Product ID: 2405 Description Description Mil-spec carbine castle nut/lock ring for securing lock plate on an adjustable stock for AR-15, M4 Related products Toxic Mil-Spec buffer tube (6 Position) $1795 Toxic Mil-Spec 3 oz carbine buffer $999 Toxic Mil-Spec Steel end plate $399 Sale! Complete Pistol Buffer Tube assembly $6999 Original price was: $6999.$3495Current price is: $3495.