Awe here we go again. 1:48 twist IS NOT accurate, and it's also VERY accurate.
Here's the general skinny on the subject, and please feel free to argue yourself blue.
Twist rate is but ONE factor in a whole system of physical facts that contributes to what we call accuracy. The 1:48 twist rate is indeed the choice of twist rates in small bores rifles, i.e. the .32, .36, .40 and even the .45., HOWEVER twist rate alone isn't the only factor. Depth of grooves plays a huge part in getting the ball to spin. So does forward velocity in r.p.s. is a funtion of exit velocity and twist rate.
The Hawken boys used the 1:48 rate of twist because they owned but ONE rifling machine and it was a 1:48, the grooves however were deep, .010 or thereabouts.
The T/C shallow groove 1:48 generally SUCKS wiht p/r/b. I just came in from shooting with a T/C .50 with .490 ball. .018 ticking, 60 grains Elephant 2fg at a paltry 25 yards and got a whopping THREE INCH SPREAD. That sucks.
My Lyman Deerstalker with the same twist rate, and load will shoot one ragged hole at 25 yards, and 1.5" at 50. Why? I don't know, but the grooves appear significantly deeper than the T/C .005 depth.
Rebuttal anyone? ::