As a time saver, I like to staple up multiple targets downrange while shooting over a chrony during data gathering sessions. Without adjusting the chrony or my bench, I find I can put up a few across and several up/down before getting error readings. A friend pointed out to me that this was not conducive to accurate readings as I was introducing angle errors. My initial reaction was Okay, I understand that but the errors will be so insignificant it'll be meaningless. Keeping an open mind, I listened to him explain the following:
For arguments sake, let's say the start/stop screens are 1 foot apart and your bullet is going 2,468 fps when it reaches your chrony. That means the instrument is measuring the flight time over the screens at 0.002468 of a second. An instrument precise enough to measure seconds to the 6th decimal point is going to be sensitive enough to detect a few hundredths of an inch added to or subtracted from the flight path caused by angle error. It could be enough to invalidate the numbers you're getting between those tenth of a grain groups you're shooting or the numbers one punches into a ballistic calculator.
1,000 yard benchresters must have every part of the game figured out in detail...what do you think of this?
For arguments sake, let's say the start/stop screens are 1 foot apart and your bullet is going 2,468 fps when it reaches your chrony. That means the instrument is measuring the flight time over the screens at 0.002468 of a second. An instrument precise enough to measure seconds to the 6th decimal point is going to be sensitive enough to detect a few hundredths of an inch added to or subtracted from the flight path caused by angle error. It could be enough to invalidate the numbers you're getting between those tenth of a grain groups you're shooting or the numbers one punches into a ballistic calculator.
1,000 yard benchresters must have every part of the game figured out in detail...what do you think of this?
