[Emperor's Child]

I've been tinkering around recently on a Battle Fleet Gothic (ie: Warhammer 40k background) mod and am trying to figure out a way to get a direct fire weapon system to hit its target 50% of the time NO MATTER the range in order to get the "Lance" weapons to work similiar to how they do in the miniature game. I want to do this in such a way that I can put other weapons onto the ship that are unaffected by the lance's alternate hit rate so that the other weapons are subject to the normal range to-hit degradation.

Has anybody done something like this?