The wait is finally over SilencerCo Octane 9mm endcaps are for sale! With this endcap you can change the end on your SilencerCo Octane 45 down to 9mm. We did a test with the 9mm endcap on a 45 Octane and the results are impressive. Watch the video and if you have a Octane 45 you can now purchase the endcap for better performance on your 9mm. This is a Silencer Shop exclusive part.