Gustavo
Well-Known Member
I've just finished the "research" on the subject of canting. First draw is that the accepted models are plain wrong, a suspicion I had since my first post on this matter.
After looking at some papers, especially an excellent one written by Jeroen Hogema, a dutch gentleman, I started to see some discrepancies among the usual published stuff (in this and other forums) regarding the correct solution to calculate the effects of canting.
One thing that especially alerted me was the "fact" that vertical deflection was almost regarded as minimal and not to worry about…weird to say the least.
Also, I contacted Rubén Nasser ("Tiro Fijo") from Paraguay and a poster here.
So between Jeroen, Rubén and myself after a very enjoyable exchange of emails, the correct solution showed up.
In short, the correct solution MUST account for LOS and Zero Range, and thus VERTICAL DEFLECTION is an ISSUE.
So the right formula to account for cant is :
X(R)=H(R)*sin(cant)
Y(R)=H(R)*cos(cant)-DROP(R)
where H(R) is height of bore line with respect to sight line (as a function of range R)
I really don't want to make a tedious thread with many formulas, but if someone is interested, just let me know and I'll post them.
Example :
MV: 2900 fps
BC: 0.490
LOS : 2.0 inches
Zero : 200 yards
Cant : 10 degrees
Dist / H( R ) / X / Y
yards / inch / inch / inch
0 / -2.00 / -0.35 / -1.97
100 / 3.55 / 0.62 / 1.30
200 / 9.10 / 1.58 / -0.14
300 / 14.65 / 2.54 / -6.97
400 / 20.20 / 3.51 / -20.21
500 / 25.75 / 4.47 / -40.64
After looking at some papers, especially an excellent one written by Jeroen Hogema, a dutch gentleman, I started to see some discrepancies among the usual published stuff (in this and other forums) regarding the correct solution to calculate the effects of canting.
One thing that especially alerted me was the "fact" that vertical deflection was almost regarded as minimal and not to worry about…weird to say the least.
Also, I contacted Rubén Nasser ("Tiro Fijo") from Paraguay and a poster here.
So between Jeroen, Rubén and myself after a very enjoyable exchange of emails, the correct solution showed up.
In short, the correct solution MUST account for LOS and Zero Range, and thus VERTICAL DEFLECTION is an ISSUE.
So the right formula to account for cant is :
X(R)=H(R)*sin(cant)
Y(R)=H(R)*cos(cant)-DROP(R)
where H(R) is height of bore line with respect to sight line (as a function of range R)
I really don't want to make a tedious thread with many formulas, but if someone is interested, just let me know and I'll post them.
Example :
MV: 2900 fps
BC: 0.490
LOS : 2.0 inches
Zero : 200 yards
Cant : 10 degrees
Dist / H( R ) / X / Y
yards / inch / inch / inch
0 / -2.00 / -0.35 / -1.97
100 / 3.55 / 0.62 / 1.30
200 / 9.10 / 1.58 / -0.14
300 / 14.65 / 2.54 / -6.97
400 / 20.20 / 3.51 / -20.21
500 / 25.75 / 4.47 / -40.64