Creating a custom rifle is an exciting process, especially when you're able to select the right parts to suit your specific needs. Whether you're looking for a reliable personal defense firearm or a rifle designed for accuracy and power, the AR-40 build kit and 8.6 blackout provide excellent choices. These two options offer versatility and performance depending on your goals. Let's take a closer look at each one to help you decide which option fits your custom build best.Creating a custom rifle is an exciting process, especially when you're able to select the right parts to suit your specific needs. Whether you're looking for a reliable personal defense firearm or a rifle designed for accuracy and power, the AR-40 build kit and 8.6 blackout provide excellent choices. These two options offer versatility and performance depending on your goals. Let's take a closer look at each one to help you decide which option fits your custom build best.