WV Archery Association
Can anyone tell me the formula to calculate a sight tape with a scientific calculator.?????
There is a DIFFERENT formula for each yard between 15 and 100 yards....or actually a different "multiplier" times the difference between your 20 and 65 plus the 20 yard setting.
So, for example, the 20 yard setting is 40.4 on the scale, and the 65 yard setting on the scale is 73.7. This leaves a "gap" between 20 and 65 of 33.3 (the KEY NUMBER). So, for the 30 yard site mark, the formula is:
33.3 (gap) Times 0.1765 plus 40.4 (the 20 yard setting),= 46.3 for the 30 yard site setting. (If your site is a ten click scale). You can set excel to round to two decimals if you have a 20 click unit.
For the 80 yarder:
33.3 times 1.3820 plus 40.4 = 86.4 for your 80 yard setting.
Normally, when I cross check these with AA, they are within 0.1 of what AA comes up with...
However, the calculator based version doesn't give anything below 15 yards...so you need to shoot in the 14 and the 11 and the bunny settings...which I do anyways, even when using AA. In the "old days" we would site in high intentionally, normally at the top of the X-ring...and that way, when we tired, we know we would be on and not sag out the bottom. hahaha, since most of us tended to shoot low when we got tired.
With care, this sucker works...but again, it is only as good as you spend the time to get the marks for 20 and 65 as good as you can get them by shooting LOTS of groups and taking out the bad shots and not settling for slop. If you have a bad 20, then this will throw everything from 15 up thru 40 off. If you have a bad 65, then most of the time everything from 44 on out is off. Works the same way with AA...that is why so few of us use 20 yards as the first setting in AA...we go for a SOLID and accurate 30 yarder and then a super accurate 65 or 70.
Again, e-mail me, cuz I ain't for typing all those formulas here on AT.
field14:tongue: :tongue: :wink:
Those are the multipliers for those two distances. Those numbers were the "key elements" of the calculator based site setting system. This system, I think, was part of the site scale unit that Killian Chek-it sites came up with back in the early 1980's. There was a metal site tape that fit onto the vertical bar that had the "numbers" scribed on it. You simply "stuck" the metal tape onto the vertical bar, and those "numbers" became the ones you used to calculate and then set your site to for different distances.How do you come to 1.3820 and 0.1765?
Shooting them in isn't quite as accurate as one would think! Of course, before the calculator based system came in, that is how nearly all of us got our site marks.Agree with ( B )...The only really accurate method I have found is to actually shoot the distance with your setup.