In my continuing long range education I stumbled onto Pac-Nor barrels website. First I noted the vast number of wildcats and secondly I note the vast array of twist rates/land combinations. How do you select a non-norm land number? In some calibers, with available twist and land combos you would be looking at 5 to +15 choices. Is it all just trial and error or is there some formula? I realize as bullet weight/length goes up you generally want twist rate to speed up but how do you determine no. of lands? Preference? Then there was even polygonal choices. From what I have read, polygonals namely Mike Rock barrels, are unbelievable shooters but I don't notice anyone on here really speaking of them. Thanks for the comments.