Forward Controls Design CNF Billet Machined Castle Nut for A5 Length RE Black

CN5F (Castle Nut, A5, Forward Controls) is an extended version of CNF we've been making since 2018. CN5F is designed specifically for the superb Vltor A5 system. CN5F is 0.1in longer, and is as long as we can make a castle nut while ensuring backward compatibility, and the stock's ability to fully collapse on Vltor's RE-A5 and our RE5F. CN5F aims to cover as much of the threaded area of a receiver extension (RE) as possible. It could be made longer, but it will run into backward compatibility issues with some REs' timing when installing the castle nut and end plate on the RE. CN5F is made specifically for the Vltor A5 system, and it will allow even the longest carbine stocks to fully collapse on RE-A5 and our RE5F. While CN5F will also work on standard TDP spec length RE, the additional length of the castle nut will prevent the carbine stock to fully collapse. Other than its length, CN5F shares common features with its smaller brother, CNF. The TDP spec castle nut is a simple and robust fastener that is almost perfect for the job it's tasked to perform. Over the years, we've consistently come up with two minor gripes, first is its staking notches seem rather shallow and short, second is we don't enjoy using the castle nut's wrench notches as serrations (our fingers invariably find their way to these sharp cutouts) to rotate it towards the end plate while installing it.