The Dirty Bird Industries Mil-Spec Carbine Buffer Kit cuts no corners. It features a true Mil-Spec 6-Position Receiver Extension (buffer tube) machined from American Made 7075-T6 Aluminum, 3oz Carbine Recoil Buffer w/ steel counter weights, a chrome silicon buffer spring, hardened castle nut with staking cuts and mil-spec end plate.
When it comes to your buffer system, quality counts. If the spring rate isn't correct, it can cause cycling issues, if your buffer uses a solid weight instead of free moving separate counter weights it can cause bolt bounce. Poor quality aluminum can lead to a fracture in the receiver extension. Unfortunately there are a ton of receiver extension / buffer kits on the market (import AND domestic) that suffer from one or all of these shortcuts in the manufacturing process.
You have Dirty Bird's word that this kit is made from the finest materials, using modern manufacturing processes. If you're looking for true mil-spec quality, don't pay more, don't settle for less; this is your kit.
7075-T6 Aluminum 6-Position Mil-Spec Receiver Extension (7075-T6 Aluminum is nearly twice as strong as 6061)