These Tuning Barrels are going to allow you to use many different Projectiles from various manufactures. It will also allow you to use many different .50 chemical rounds.  The Tuning Barrels also come with the threaded end cap. These are custom orders. We do have some in stock and may take a few days longer than our normal turnaround time as they are a popular item. Please also feel free to contact us about doing installations. We offer both Barrel install and launcher dying. For us to complete the install and launcher dying , you will need to send us your launcher. Please contact us via email for information on this. Thank you