PDA

View Full Version : Calling All Rifle/Math Genius Skirmishing Experts....Can Anyone Answer This "Sighting In" Question?



Southron Sr.
08-16-2015, 11:16 PM
O.K...You have a replica Fayette Rifle with a Whitaker Barrel. It is shooting the 405 Grain Hodgdon Bullet propelled by 48 Grains of 3Fg GOEX.

By pure luck you drilled a Peep Sight Hole in the rear sight leaf that is "Dead On" the 10X Ring at 50 Yards "Off the Bench."

How HIGH ABOVE the 50 Yard Peep Sight Hole should one drill another Peep Sight Sight Hole to hit the X Ring on the 100 Yard Target???

Inquiring Minds Want To Know!!!!

MANY THANKS IN ADVANCE!!!!

P.S. My Cousin said he could help me because he was an Arithmetic Major in College, but, as it turned out, he has forgotten most of what he knew when he Graduated. So, he couldn't help me.

pastore
08-17-2015, 12:10 AM
That will depend on where the bullet strikes the 100 yard target using the peep that is in use now.

P.Altland
08-17-2015, 05:53 AM
In other words, shoot a group at 100 with your 50 yrd peep using the same point of aim. Measure the distance between the point of aim and the point of impact in elevation and Windage. Input those numbers into the standard sight radius formula. The resulting numbers will be the distance in .000" above, left or right of your reference hole (50 yrd. peep).


Sent from my iPhone using Tapatalk

bobanderson
08-17-2015, 06:26 AM
Just in case you don't have the calculation, after you shoot that 100 yard group with your 50 yard sight, measure the sight radius of your rifle. That is the distance from the rear face of the rear sight to the rear face of the front sight. Divide that number by the distance to the target measured in inches (100 yards x 3 feet x 12 inches or 3600).

The result is how much you move your sight up to achieve 1" of elevation change at 100 yards.

For a rifle with a 29" sight radius, to move your point of impact, move the sight .0085".

This works at 50 yards also. The number there is 1800.