Berger reccomends a 1-8" for both their 180 grain offerings. Although you said 160-170, a 1-8" won't hurt anything and gives you the option for a heavier bullet if you desire.
my old man shoots 168 vlds in his factory tika with no issues. Hard to believe with VLDs but he blew one right through a cow moose this year at 235yds. I couldn't get the 190 ABLRs to shoot out of my .300WIN sender but it also loves 185VLDs