I have a .54 with 1:66 deep cut rifling. I have read and re read Brown Bear's discussion on rate of twist: http://forums.outdoorsdirectory.com/...tlock-question
And his experience with .54 New Englander here:
Brown Bear said that deep rifling with 1:48 works great, I am wondering if anyone has experience with 1:66 with deep rifling for something like the Hornady Great Plains boolet? That twist maybe just too slow for heavier boolets?
Thanks in advance.