Grayguns

Next, for our extreme testing, we greatly reduced the case wall support of the P320's 9mm barrel. (Starting at about 1 minute and 45 seconds into the video.) But first, Bruce briefly explains the previous testing where he shot the P320 significantly out-of-battery and then completed more testing without a locking shoulder on the barrel. This will help explain the "blowback design" reference in an earlier video.