I've used antiseize on stainless screws & actions with fine results, as in the next time I needed to take the screws out they came out fine. Only problem is that the darn stuff seems to end up all over the place as soon as I open the jar. I haven't had much experience with Ti actions, but have worked with Ti in other applications plenty and have had to deal on many occasions with badly galled or seized screws, taps, tubes, etc. We always used antiseize when assembling anything Ti. Whatever you do, don't install them dry!
