What do we really know about the transonic zone?

[Distant Thunder]

I like to patch .001 to ,002" over my finished base diameter and then size the patched bullet to the finished base diameter. With my .40-65 the chamber was cut specifically for R-P brass and it has a loooong freebore. The mold was cut to patch to .411 and is then sized after patching to .409 which is a slip fit in the brass and the freebore. The result is a rifle that can shoot under 1 moa at 220 yards and very well out to 600 yards. And that's with me on the trigger!

Patching to less that case or groove diameter also works, but the bullet has to bump up to the case ID and or freebore diameter before it moves forward. I just like to skip that bump up. Either way works well if everything else is in line. Heck I'm amazed how well straight bore diameter bullets shoot and they bump up even more!