Long Range Shooting Essentials
Basic Essentials Of Long Range Target Shooting - Part 1.
I aim to provide a series of articles about the basic steps to follow to improve your long range shooting ability and understanding of ballistics in our sport. It will start off with information for the new long range shooter. Those of you with more advanced skills can jump ahead to the later articles.
Top of the list is the sighting adjustment system of your rifle scope, this article will assume it is graduated in MOA, (minutes of angle). Don’t worry too much if your scope uses a different system as downloads are available on the website to convert MOA to other units if needed.
The adjustment of your rifle scope is meaningless if you don’t know the size of the target and its scoring rings. There are ICFRA plot sheets drawn for the three target frame sizes we currently use and these are available to be downloaded from the website. These plot sheets present a scaled drawing, (plot) of the target with grid lines drawn at one MOA intervals.
There are three really important pieces of information that will be needed in order to use ballistics as a tool to get you on target and also to increase your accuracy. It is essential to know what projectile you are using. The projectile’s weight, (gr) and the ballistic coefficient, (BC) measured using the G7, (G1 only if G7 data unavailable) drag model need to be known. These two pieces of information can be gathered from the box the projectiles came in or gathered from the manufacturer’s website on the internet.
The other piece of the ballistic puzzle is the muzzle velocity of the projectiles that are being used. This is generally measured in fps, (feet/second) while Australia may follow the metric system in most areas of measurement, ballistics down under is measured in imperial units. The velocity of the projectile may be the most difficult data to obtain as it is a direct measurement taken of the bullet leaving the barrel of your rifle. It requires using a chronograph and most rifle clubs have one available for members to use.
Berger Bullets Free Ballistic Application
Using The Data
The information gathered so far will enable a number of useful tools to be used to help establish a drop chart for use at the rifle range. It is an essential requirement when competing at long range to know the correct sight elevation adjustment for each range distance. Clubs will not tolerate members for too long, who don’t know the zero adjustment for the range distance. Too much time is wasted if the member cannot be on target for the first sighting shot and misses the target completely.
The Drop Chart is the starting point for all long range shooters and will calculate the elevation required to be wound onto the rifle scope for the various ranges. Berger Bullets have available for free on their website a really good (Bryan Litz designed) piece of software for calculating ballistic tables.
- Scope manufacturer's handbook
- Convert from and to MOA Excel file (may be needed if scope not graduated in MOA)
- Download a ICFRA Plot Sheet to work from
- Download Berger Bullets free software
- Contact your rifle club and ask to use the chronograph to record muzzle velocity in fps
Adjusting the scope for range distance...
Sight your rifle in at 100-300 yards using your target ammo and record both the elevation and windage adjustments. This becomes your zero reference adjustment that the drop chart will be based on for all range distances.
Once you have the muzzle velocity (fps) and projectile data (weight in gr, BC in G7) and have measured the centreline of the riflescope above the centreline of the rifle bore you can use the Berger Ballistic software to calculate a drop chart for your rifle. Read the drop from the column labelled 'Trajectory' and adjust your scope from your zero setting up to whatever range you are shooting on.
The ballistic chart can be used to set up the the range distance on the scope before even arriving at the rifle range. Once at the range and your first sighter is marked on the target the plot sheet becomes very useful to accurately measure using the MOA grid lines the elevation correction needed.
Adjusting the scope for range windage...
If you know the speed of the wind then you can use the drop chart by looking in the column labelled 'Drift' and adjust the scope to suit the wind condition. The plot sheet now becomes your best friend because after your first sighting shot is marked on the target you can use the MOA grid lines on the plot sheet to provide the wind correction you need to hit the centre.
Using a ballistics table and a plot sheet will give even a new shooter the confidence needed to get to the centre of the target. Staying in the centre of the target requires wind reading skills and a knowledge of your bullets ballistics.
Continued in Part 2.
Ian Pavy safclass.com.au