Major, down 1 point for a "C"; down 3 points for a "D" Minor it is -2 and -4 for a C and a D respectively. Since the scoring is points divided by time, how much it costs you is relative to the hit factor of the stage. Hit factors equate to points per second. If the hf is low, say a 3 HF each point is worth a third of a second. If it is a high hit factor, say a 10 each point is worth a tenth of a second. In other words a close up stage with easy targets it is worth more to go fast, for stages with harder shots it is worth more to take your time to get points.
The exception to this a stage that requires you to do a lot of "stuff" that has nothing to do with the shooting, but the shots are close and easy. An example of this was Stage 3 of the Provincials "Sleds of Samwise" which took top shooters in each division around 5 seconds to accomplish something that would otherwise be done under two. Three targets at 7 yds, but you had to pull a sled loaded with your mags about 5m back to you, then load your gun, then shoot. A stage like this could be shot in 1.8 sec. 30 points divided by 1.8 is a 16.666 HF, but as it was shot, the top time was 30 points divided by 4.64 for a HF of 6.4655. It changed a hoser stage into a points heavy stage.