10-4 that. Never really thought about that aspect. Ive done a good bit of research on the 3 grooves just for my own curiosity sake and had never heard of that issue. As well the aforementioned aquaintances using the barrel haven't had any issue, but then they lag a solid 300 fps behind your application. Just goes to show...just when you think you had something figured. Your round is kind of a different ballgame though compared to most mere mortal cartridges lol.