"Most" commercial ammo for .308 is between 150gr and 168gr, so you'll be fine. 1:10" will easily work for 175gr SMK and should work for 190gr SMK, possibly even 200gr SMK. At the high end (like 200gr) it can depend on how long your barrel is and how fast you push the bullets. A 1:12" twist will work for most bullets up to around 150gr.
