RE: How important is barrel length?
Loading via OCW negates harmonics voodoo on many levels...
Sine waves, peaks and valleys...easily understood by the google experts, but whentranslated, the best exit pointis when the muzzle is at it's calmest period of occilation, sweet spot, which is when the shock wave, induced by the detonation of the charge (NOT the recoil of the weapon), is back at the chamber end of the delivery system. Hitting a "sweet spot" during this ever diminishingback and forth migration of the "wave"is when you need the bullet to break from the muzzle.There's several pointsthroughout the load range this happens and usually hitting one at or near the top of the data is, worst case scenario,easy....I also find one about 2/3's the way up that shoots just as good but with understandably less velocity.
Once OCW is fully understood, providing the bore is grade "A", ANY barrel contourcan be made to shoot well, less any hocus pocus like a sims vibration thingy or a BOSS. Have myself never gone over 20 or 25 rounds in R&D to find a "sweetspot" in any good barrel tested...and from there it's just messin' with seating depth to squeeze it down a little.
OCW not only negates contour worries in a good barrel but diminishes such voodoo as bullet lot # differences, powder lot # differences, case capacity varience issues, weather/temp/humidity related issues, and such.......
It also enables one savvy enough, to R&D "swap loads". All my rifles have a cheaper bullet to play with on steel and varmits....and a TSX bullet of same grain weight and similar BC with which to stomp freezer meat dead. Not a huge feat until you realize my swap loads don't mandate a scope zero change to make the swap.......
The fish, BTW, is a dink......................................