It also depends on what purpose the rifle will be for. If they're primarily a stealth player, the semi-autos gain a massive advantage since hits from undetected are almost always an instakill. This eliminates the bolt-actions' damage advantage and those rifles become an outright liability when you start needing quick follow-up shots for groups of enemies or to compensate for a miss.

However, if the rifle is for loud purposes then the bolt-actions start winning out as the lack of stealth damage boost makes the semi-autos incredibly underpowered for taking out alerted enemies (especially Unidad).

Of course, there's always just going for the BFG-50A since that's basically a weapon which combines the best of both worlds - semi-auto firing and the .50 cal power of an HTI.