This question has come up a couple of times for me as I watch the hunting videos of all the big guys shooting birds off barn roofs at 50+ yards. Are you using something like Strelok to get hold under? Are you using the old "Rifleman's Rule"?
The reason I ask is that as an old retired academic I decided to solve the problem myself by writing a simple pellet ballistics program. It really isn't that difficult if you limit yourself to subsonic speeds, no wind, no spin drift, and have access to the G1 drag profiles. Anyway, what I noticed is that I was getting different results from Strelok on elevated shots. My results closely match his on low angle shots (accounting for barrel angle to zero at a specified range). But as the barrel elevation increased my results differed from his. So it has to be my error, right. That's what I thought. Then I started looking closely at the tabular results from Strelok. I noticed that the pellet velocity didn't change at a given range no matter how large an elevation angle was used. That is flat out incorrect! As you elevated the barrel gravity has a comport of force that acts in the same direction as drag and will slow the pellet down (just a bit, but it gets larger the higher the target is).
So it may be that he is correcting for this somewhere in his calculations that I cannot see and that his hold results are good. So that is why I am asking if anyone uses his holds with success. I don't have a location where I can put a target up high and shoot it to check my results. Hmm, I need to find a flagpole somewhere that will allow rifles to be shot at it ... not likely.
Cheers,
Greg
The reason I ask is that as an old retired academic I decided to solve the problem myself by writing a simple pellet ballistics program. It really isn't that difficult if you limit yourself to subsonic speeds, no wind, no spin drift, and have access to the G1 drag profiles. Anyway, what I noticed is that I was getting different results from Strelok on elevated shots. My results closely match his on low angle shots (accounting for barrel angle to zero at a specified range). But as the barrel elevation increased my results differed from his. So it has to be my error, right. That's what I thought. Then I started looking closely at the tabular results from Strelok. I noticed that the pellet velocity didn't change at a given range no matter how large an elevation angle was used. That is flat out incorrect! As you elevated the barrel gravity has a comport of force that acts in the same direction as drag and will slow the pellet down (just a bit, but it gets larger the higher the target is).
So it may be that he is correcting for this somewhere in his calculations that I cannot see and that his hold results are good. So that is why I am asking if anyone uses his holds with success. I don't have a location where I can put a target up high and shoot it to check my results. Hmm, I need to find a flagpole somewhere that will allow rifles to be shot at it ... not likely.
Cheers,
Greg
