jmden,
This is a common question, and one we're happy to answer because it's an opportunity to teach about ballistic calibration.
Some programs that allow 'truing' don't provide any guidance as to what ranges you should shoot the calibration or 'true' points. Shooters will typically go for many short intervals, which, for other programs might be necessary due to fundamental inaccuracies in the solver. In other words, some solvers aren't accurate until you've told them many points of observed drop.
The Applied Ballistics solver is more refined, and is written to work with the supplied BC library and custom drag curves. For this reason, trajectory predictions are more accurate, so you don't need as many calibration points.
The few calibration points that are recommended are:
First is at the extent of the rifles supersonic range. This point will adjust your MV to coincide with your observed drop where the bullet has slowed to around 1340 fps (this is the first recommended range). Honestly, once you've calibrated at this range, you should be good for many 100's of yards past it, as well as back to the muzzle.
IF you anticipate shooting much further than the first calibration range, then you can shoot an additional point which coincides with Mach 0.9 (99% sure it's Mach 0.9, might be 0.8). Really, I don't think there's a need for a third calibration point, but we made it anyway.
The principle of ballistic calibration is to get as much distance as you can between the calibration points. It's the same principle that makes it obvious that you shouldn't calibrate at 200 yards with a 100 yard zero; there's just not enough drop to calibrate. Likewise, if you calibrate your first point at 1200 yards, and have additional targets at 1400 and 1800, ignore the 1400 yard target (because it's only 200 yards past the 1200 yard point) and go straight to the 1800 yard target.
The most common response is: "we don't have targets at the recommended ranges". It's OK to give it calibration points inside the recommended windows, the program will calibrate outside of those ranges. The recommended ranges are there to show you the optimal points to calibrate in terms of the bullet's Mach number.
To bill's question, there are some misleading statements on the instruction page, the one you mentioned is one of them. The first calibration point will always be MV. After that the program is calibrating drop.
-Bryan
This is a common question, and one we're happy to answer because it's an opportunity to teach about ballistic calibration.
Some programs that allow 'truing' don't provide any guidance as to what ranges you should shoot the calibration or 'true' points. Shooters will typically go for many short intervals, which, for other programs might be necessary due to fundamental inaccuracies in the solver. In other words, some solvers aren't accurate until you've told them many points of observed drop.
The Applied Ballistics solver is more refined, and is written to work with the supplied BC library and custom drag curves. For this reason, trajectory predictions are more accurate, so you don't need as many calibration points.
The few calibration points that are recommended are:
First is at the extent of the rifles supersonic range. This point will adjust your MV to coincide with your observed drop where the bullet has slowed to around 1340 fps (this is the first recommended range). Honestly, once you've calibrated at this range, you should be good for many 100's of yards past it, as well as back to the muzzle.
IF you anticipate shooting much further than the first calibration range, then you can shoot an additional point which coincides with Mach 0.9 (99% sure it's Mach 0.9, might be 0.8). Really, I don't think there's a need for a third calibration point, but we made it anyway.
The principle of ballistic calibration is to get as much distance as you can between the calibration points. It's the same principle that makes it obvious that you shouldn't calibrate at 200 yards with a 100 yard zero; there's just not enough drop to calibrate. Likewise, if you calibrate your first point at 1200 yards, and have additional targets at 1400 and 1800, ignore the 1400 yard target (because it's only 200 yards past the 1200 yard point) and go straight to the 1800 yard target.
The most common response is: "we don't have targets at the recommended ranges". It's OK to give it calibration points inside the recommended windows, the program will calibrate outside of those ranges. The recommended ranges are there to show you the optimal points to calibrate in terms of the bullet's Mach number.
To bill's question, there are some misleading statements on the instruction page, the one you mentioned is one of them. The first calibration point will always be MV. After that the program is calibrating drop.
-Bryan
