Now That You Know a Thing or Two
Calibrating Your Scope for Shooting
In the first three parts of this series we looked at the rifle, optics, ammunition and the basic principles for long range shooting. We finish our Hellsgate Tactical Precision Rifle Clinic by discussing the final thing you’ll need to do to start shooting.
Sighting Your Scope
You are not going to be able to hit targets at 1000 yards without doing a little preparation. The first step is to zero the weapon at 100 yards. This is pretty much a standard distance for setting the zero. To understand the need for zeroing a scope you need to understand the relationship between the path the bullet takes and the point of aim. A bullet does not follow a straight line, it follows an arc. How big this arc is, is determined by the distance to the target and the ballistic performance of the round.
When setting zero you should fire three rounds at the target, and then evaluate your shots. If they are grouped within a ½ inch, or whatever is acceptable to you, then adjust the scope to bring the group to the bull’s eye of the target. Fire three more rounds to verify that you are on target at 100 yards. Once you are satisfied set you’re scope to the new zero settings by loosening the windage and elevation turrets and moving them so that the “0” on the turret lines up with the new zero setting.
One thing to keep in mind is that you may have to start your zero procedure at 25 or 50 yards to get the group on paper, and then move out to 100 yards. Now that you are able to precisely and accurately hit a target at 100 yards, it’s time to move out and determine the adjustments needed to the scope to hit a target at 400 yards. Why 400 yards? Nathan explains,
The amount you dial up to get from 100 yards to 400 yards in a specific atmospheric condition is what we input into the ballistic calculator. If we do everything right the calculator will be able to predict what we need to dial in any condition and at any distance to be within .1 MILS of the target. The 400 yard distance works well in getting the most accuracy out of a ballistic calculator but other distances will work. I think the reason many use a 400 yard zero is because it is close enough to rule out updrafts and other unpredictable factors that the ballistic calc is unable to account for.
The principals used to set zero at 100 yards is the same used to determine the 400 yard zero. The only difference is that you will not reset the scope turrets. One very important item to remember is to record the settings on your scope for the 100 and 400 yard zero a log book is a good place to do this, in addition to the scope settings make note of the weather conditions. You will also want to record this information for every long distance shot you make, this data or dope can be used to quickly set up for that long shot.
A ballistic calculator is another handy tool, while it is a nice to have it is not a must have. There are plenty available for your smart phone, tablet or PDA. This tool takes data on your weapon, round, scope and the weather and spits out a scope setting that you can use to get you on target. But remember the data output is only as good as the data you put into it.
Hopefully I gave you enough information to get you started, and you now have an idea on what it takes to make that shot at 1000 yards.
Good Luck and Good Shooting.
Hellsgate Tactical Precision Rifle Clinic
Part 1: Choosing the Right Rifle and Scope that Fits your Need
Part 2: Importance of Choosing the Right Long Range Ammo
Part 3: Basic Principles for Long Range Shooting