Most of us can figure out how to zero our rifles at 100 yards. But do you know how to get a solid zero at long range — as far as 1000 yards? You need to know your ballistics, otherwise you may waste a lot of ammo “sprayin’ and prayin’”. You definitely need to know your exact muzzle velocity, within a few FPS. This is not as simple as it seems, because it is not uncommon for chronograph results to be off by 10 to 20 fps or more, just through calibration error. Accordingly, you may want to test with a pair of chronos and record the results from each (you may be surprised at the variances).
Video Illustrates Zeroing Process
The process of zeroing rifles for long range is covered in a new “Firearm Science” video from the NRA. This video features George Reinas, a popular competitor on the Top Shot TV Show. George demonstrates how to adjust his scope to compensate for bullet drop at long range. Our friend Dennis Santiago was involved in the making of this video, which was filmed at the Burbank Rifle & Revolver Club in Southern California. The video is narrated by the talented Jessie Duff, one of America’s best action shooters.
When zeroing at long range, you should first consult a good ballistics program. Select your baseline zero distance (such as 100 yards), then plug in the MV along with salient environmental factors: Altitude, Air Pressure, Temperature, Humidity. After you enter bullet BC, your ballistics program will calculate the drop to the target, expressed in MOA or Mils. Some programs will actually list the number of clicks up from your current zero.
You can print out the data from your ballistics solver as a “drop chart” that can be attached to your rifle stock. If you shoot at various altitudes you may need multiple drop charts.