Striker Book 1, page 41, "Counterbattery fire" addresses the effect of variable ballistics on trying to locate the gun from which the round was fired: counterbattery radar gets a roll to locate a gun firing an artillery barrage (Striker Book 3, page 43), and the variable ballistics cause a die modification to that roll of twice the tech level difference between the round and the radar. If a round doesn't have variable ballistics, it's treated as a TL 7 round.
So, for example, a TL 10 counterbattery radar set can spot the location of a gun (when it fires) on a 4+. If the gun is not using variable ballistics, the radar operator enjoys a +6 to his roll (10-7=3, multiplied by 2 = 6), which makes it a sure thing (the math means any CB radar of TL 9 or better will always spot a gun/howitzer firing regular rounds). If the round has variable ballistics and is of the same tech level as the radar, the DM is zero - the radar operator gets his base 4+ roll. If the round was, say, a TL 12 round with variable ballistics, the radar operator suffers a -4 to his roll.
