I've had the best results using flatbase, relatively blunt cast bullets in subsonic loads. The danger of sticking a bullet in the bore is just too great with jacketed bullets, and if you've ever stuck one you'll know you don't want to do it again. Also, a VLD boattail gains you nothing in a subsonic load at normally used ranges (<300yd.) but does cost quite a bit more to buy. One of the best cases I have found yet for dedicated subsonics is a 32 H&R mag, chambered in a .308 dia. barrel. It'll shoot the 220gr. Lyman at 1050 fps with a case full of 1680 and SDs in the low single digits, using a 1:10 twist barrel. To do this with jacketed of similar weight you'll need a 1:8 barrel, not a real common thing to run across.