The other morning a buddy and me were out checking cold barrel shots. On my 243 with an 8 twist barrel shooting 105 gr Berger vld's going 3050 fps he said it looked like a corkscrew through the spotting scope. We were either shooting 750 or 950 yards I don't remember which. Anyways the gun was on target so I had him shoot and I spotted and it sure did look like a corkscrew. All of our other guns would produce a normal vapor trail but this one sure does look funny. Anybody have a clue? Surely it's not unstable is it? I've taken this combo to 1400yrds before and it's accurate so I'm confused!!!!