The "Rifleman's Method" (for adjusting for uphill/downhill shooting angles) changes your zero.

In an earlier post I showed the "Rifleman's Method" for adjusting for uphill/downhill shooting angles. It has 3 problems.

1. Gravity is no longer operating at 90° to the bullet, so gravity does less (a fishing rod at 45° sags less than a horizontal one, OK?).
2. Your sights are higher than the bore, which changes the zeroing geometry.
3. The bullet takes longer to get there, and slows down.

Using a typical 30-30 deer rifle with a scope 1.5" above bore, and using the diagram to the left, at 100 yards uphill distance on 45° you will be 0.5" high (mostly due to sight height), but at 300 yards 4" low (due to reduced velocity). So at large angles, when the bullet is starting to slow down (like a 30-30 at 300 yards) this method isn't enough, you would need to look at a ballistic table. 25° uphill with a 30-30 at 220 yards, this method gets you 0.4" low. (220 uphill is about 200 horizontal at 25°).

The new deskop version

Hello folks, The new Ballistic Simulator program is ready.

• Use your own target, background and sight graphics to simulate how you shoot in the field
• Infinite random Scenarios - wind, range, zero, uphill angle, target speed
• Zeroing Wizard
• Chart different properties of different loads
• Save your custom loads
• Run offline on a thumb drive on any computer
• Export to Spreadsheet
• Mil or MOA scope adjustment
• 6 reticle types, custom crosshair thickness, plus iron sights
• Moving targets, changeable wind
• Mildot rangefinding practice

It allows you to simulate your shooting environment exactly. Same load, same sights, same target, scaled to the real world. I really think this program will pay for itself pretty quickly, especially if you have more than one rifle. You can set up a simulation of your own riflescope and pet load, then practice adjusting the scope at known and unknown ranges, under varying conditions.