G&R Tactical is doing every AR-15 builder everywhere a great service. They managed to talk ALG Defense/Geissele Automatics into letting them sell their excellent barrel shims separately!
If you have ever built an AR and had to struggle to get the proper torque setting on a barrel nut while also lining up the gas tube port, you know what a pain it can be. These shims allow you to time everything and more easily put that magic 40 lb ft of torque on the barrel nut. Now you can just say no to cheater bars! These shims work so well that I have installed an ALG Defense EMR to proper torque without a vise!