The answer is "whichever one shoots best out of your rifle". I have a 185 Juggernaut .308 Varget load that is dead nuts precise that I use in 300 yd monthly matches. I have done very well using it. The rifle has .085" freebore, which is a tad short for the 185s, although the boattail/bearing surface junction is still above the neck/shoulder (just barely). With .098" freebore, you can easily load any of the bullets you listed, as well as the 185 Juggernaut. The one(s) that give the best precision are where I would start. However, if there is much wind where you shoot, BC would also be a consideration, even at only 300 yd. We often get twitchy winds later in the day in our 300 yd match, maybe in the 3-7 mph range, but it can easily be enough to push you out of the 10-ring if you miss the changes. In that regard, something with a higher BC than the 168 SMK might just save you a point or two per match. I'm fully aware that many, many 300 yd matches have been won over the years with the 168 SMK. However, it has been around a long time and there currently better designs with more favorable BCs available to you, as long as you can develop a load with equal precision. The 168s will certainly work, it's just not the route I would go unless I couldn't obtain equal (or better) precision with one of the higher BC choices.