Millett - Shooting Tips (2024)

Extended Ballistics: The .338 Lapua Magnum, 250-Grain BTHP Match Round

by Major John L. Plaster, USA (ret)

Lately I've done a lot of firing with my Savage 110BA, .338 Lapua Magnum rifle, taking on targets up to 1400 yards away.

My preferred load is the 250-grain match round, which is offered by Black Hills and Hornady, both of which have proved accurate in my rifle. To begin the process of fine-tuning ballistic data, I calculated the target knob settings for elevation and windage out to 1500 yards. My Millett LRS scope has 1-10th mil increment knobs, so I first worked up this data in mils.

This 1-10th Mil data is also useful for my Bushnell HDMR riflescope, which has both 1-10th Mil knobs and a Horus H59 reticle, which contains a grid of holds and leads at increments of 1/5th Mil.

Knowing that most other shooters have 1/4 MOA target knobs, I worked up that data too, offering you both Mil and MOA versions. Whichever you use, KEEP IN MIND that this data is a starting point and, like me, you'll fine-tune it by firing at assorted distances.

Although there are slight variances between the Hornady and Black Hills loads (due to a 50-feet-per-second difference in muzzle velocity), their trajectories are so close that you can use this as starting data for fine-tuning either round.

Also, note that my LRS scope has a 35mm tube and a 56mm objective lens, requiring that it be mounted 2 inches above the bore, a half-inch higher than some other scopes.

I analyzed the trajectory differences between mounting it 2 inches above the bore, and 1-1/2 inches, and found the variances less than 1/2 MOA all the way to 1000 yards – or less than 2/10ths of a mil. Again, that's close enough to start, after which you can fine-tune your data.

This original trajectory and windage data were computed using Sierra Infinity 6 software, after which I manually converted it into 1/10th mil and 1/4 MOA target knob settings. Sierra's software assumes a 24-inch barrel, sea-level altitude and 59-degrees F. temperature and, as cited above, my scope mounted two inches above the bore.

1/10th Mil Settings for the .338 Lapua Magnum, 250-grain BTHP Match Round

Settings rounded off to the closest 1/10th of a Mil