Tough call really, both are excellent performers. Recoil will probably be slightly easier with the 165gr and you'll like get better expansion. The 155's may do a little more damage, but probably not much more. Six of one, a half dozen of the other.
For what it's worth, some older factory 155gr Gold Dot's did around 1100 fps from my 3" Kahr CM40, and 165's (although not Gold Dots, most were about neck and neck) did about the same. For example, the 165gr Critical Defense clocked faster than the 155gr Gold Dot, even though the CD wouldn't be my first choice of the two.
Last edited by SDGlock23; 09-24-2012 at 08:42..