Long range advice.

[Dustin few]

I'm shooting a browning BAR mark II 30-06, 155 grain Hornady BT HP with 51.0 grains of H4350, I have a 4-12 Leaupold. I zerod my rifle at 300 yards and my bottom dot is 400 yards. How much would my bullet drop at 500 yards? Am I even still in the scope?

 

[macgrumpy]

Assuming that the scope is using the Leupold LR/LRV Duplex reticle the subtension from the center of the scope to the 500 yard mark in the scope represents just under 8 MOA at 12x. The trajectory of your load will cause the bullet to drop a little less than 9 MOA from 300 to 500 yards so at max magnification you will probably see the bullet impact approximately 5 inches low from your point of aim at 500 yards.

 

[Bart B.]

I think your load's muzzle velocity is between 2500 and 2600 fps. Most load data for it using H4350 lists a minimum charge of about 54 grains.

I ran Sierra's software for that bullet and it shows it will drop about 35 to 38 inches below point of aim at 500 yards if zeroed at 300. That's about 7.5 MOA. Solid line's at 2500 fps, dashed at 2600 fps.

 

[imashooter]

Goodness Bart B. Nice chart. Are others available somewhere? Thanks.

 

[Bart B.]

That's from Sierra Bullets' Infinity Software; possibly the best one available.

https://www.sierrabullets.com/products/infinity-software/index.cfm

Most all company's bullets are listed with their ballistic coefficients. I selected the one you use, plugged in both velocities, run the program, selected the chart display mode, copied then cropped the computer screen display to upload into my post. Neater than pressed shirts and pants.

 

[imashooter]

That's from Sierra Bullets' Infinity Software; possibly the best one available.

https://www.sierrabullets.com/products/infinity-software/index.cfm

Most all company's bullets are listed with their ballistic coefficients. I selected the one you use, plugged in both velocities, run the program, selected the chart display mode, copied then cropped the computer screen display to upload into my post. Neater than pressed shirts and pants.

Thanks. Very nice. Very easily readable.

 

[stoky]

I miss the cursors on the old Ballistic Infinity, where you could pick the exact coordinates off the curve.

 

[The_Next_Generation]

If you have a smartphone (either Android or iOS) Strelok is a great free app you can try out. Even if you don't have the right phone, someone around you probably does.

There are some other free apps out there, but I have found that the software from most "brand-name" bullet manufacturers lack features that Strelok and others offer. If you have $10, Shooter is a good option. Ballistic JBM by Applied Ballistics is also a great option if you have an iPhone.

These apps will take your load velocity, projectile BC, environmental conditions, etc all into account. The projectile info on BC, length, and so on can be found on the manufacturer site (normally) or info derived from Brian Litz's library