I have a set of 3 data points where X represents the amount of gunpowder in a cartridge (by weight in grains), and Y represents the peak chamber pressure of the round when it is fired:
- (0, 200) – no powder, but >0 pressure because the casing still has a primer ignition when the trigger is pulled.
- (23.2, 37400)
- (25.8, 51200)
I’m trying to decide on which type of equation to use to find a curve that intersects each of the points in a way that allows me to most accurately estimate chamber pressure for any given powder charge above 0.
y = AeBx + C seems like a good option, but then so does y = Arx + C.
Perhaps these are effectively the same, and somebody can educate me on reasons to use one or other other?