Ricky, thanks for taking the time to check it, I REALLY appreciate it !!!!

Stuff happens, but I guess in your case this was a fortunate event, because you ended up with a great shooting rifle.... I know that bullet works in the Texan, which is also a 14" twist (reported to be that, anyways)…. The fact that it works in a 14" is still a VERY valuable piece of information, because the original Koble prediction was for an 11" twist.... I have suspected for some time that the Kolbe program calculates too great a loss in stability for my Rebated Boattails, and this bullet in a 14" twist is absolute proof of that....

By extrapolation, since the 154 gr. BBT is 3.0 calibers long, this information should be scalable to the other calibers where I used the same proportions.... Twist rate in inches is proportional to caliber, so if the 154 gr. BBT is stable in a 14" twist, we should also see similar stability from the following 3 caliber long BBTs in proportional twist rates....

7mm (.284 cal) 121 gr.... 13" twist instead of 10"

.257 cal 90 gr.... 12" twist instead of 9"

.224 cal 60 gr.... 10" twist instead of 8.5"

While I can't draw firm conclusions for BBTs of other proportions, it certainly points the way to being able to use them in slower twist rates than the Kolbe Twist Calculator predicts as well.... Now it is time for me to try and figure out a "revised" base dimension to input into that calculator to come up with a better prediction for the minimum twist rate required.... Again, many thanks....

Bob