Extending the range your comfortable shooting to doesn’t have to be a confusing black hole of information. Therefore I’m not going to baffle you with the technical bullshit you probably don’t need to know. Look that up in your own time.
Let’s face it, most shots in hunting situations are well within 400yards. The vast majority of people wouldn’t feel confident shooting past 250 yards, as it’s beyond that 250-300 yard mark where compensating for bullet drop becomes a bunch more important for the usual deer rifle.
There are basically 3 ways to deal with bullet drop, not counting the unethical method of just holding above the animal and making sure your mags full.
Manual MOA (minutes of angle) calculations is the clear favourite of the more serious long range shooter. This involves calculating you’re “come up” with either a drop chart, ballistics app or a rangefinder set for your exact load. This does take time and practice to work out on the fly but is the seriously accurate method for really stretching your legs.
Ballistic recticles are a series of markings on your cross hairs, these loosely correspond to ballistics. It’s fast and simple and fine for shorter ranges, but not nearly exact enough for truly longer ranges.
BDC turrets involve all the calculations being done prior, so you simply dial the distance you intend to shoot.
These are all good systems for dealing with bullet drop, but I’m going to focus on what in my opinion is the simplest and best suited to hunting scenarios.
Custom turrets or BDC scopes (bullet drop compensation) is very simply a custom engraved elevation turret made specifically for your load, rifle and preferences.
With this system there is no drop chart or ballistics calculator on your smart phone, the only other piece of equipment you need is a range finder capable of accounting for angle to give you your true horizontal range.
There are a number of scope manufacturers that produce BDC turrets and also a few companies making aftermarket custom turrets for a range of manufacturer’s scopes. Again to keep things simple I’m going to focus on one manufacturer’s version which is the Leupold CDS (custom dial system).
CDS is available free on both the VX-3 and VX-6 range of scopes, these come boxed with standard turrets but with the purchase price you also get one free custom turret that you order once you’ve settled on a load your rifle likes and have worked out all the other necessary data.
This is the important bit, unless your data is accurate you will find more and more error the further you stretch the rifles legs.
It’s really important to provide a ballistic coefficient and a velocity that is exact. Using factory ammunition you will find this information on the box but it’s usually far from perfect and no rifles the same. Go see your gunsmith or your local range and use a chronograph to get a much more accurate velocity figure. Do this how you intend to use your rifle in the field so have your silencer fitted and either a clean or fouled bore. Most commonly a rifle will like a bore fouled to a certain degree.
The ballistic coefficient on the pack is usually not super accurate. The easiest way to get a more accurate figure is to use resources such as Applied Ballistics by Bryan Litz, this will at least be more accurate than the figures on the box.
Some generalisations will need to be made such as elevation, temperature and air pressure. This should be the average that you hunt at. For example I have mine set at 1000m above sea level as I use it in all open country and most of the time this will be between about 600m and 1600meters. If I was to shoot out to 800 yards than this variation would have an effect of just over 2inches, this is still within the kill zone of an animal and I’m not interested in shooting that far anyway. So this type of generalisation is fine for my situation, and a similar approach for temp and air pressure can be taken.
You need to let them know your zero distance as well as the height at which your scope is mounted. This is measured from the centre of the bolt to the centre of the scope tube.
Now that you’ve got all this info together simply contact the New Zealand importer which is NZ Asia in Nelson or get in touch with the Leupold custom shop directly through the website. Give them all the data and wait for the dial to show up. I’ve found both the New Zealand importer and the custom shop to be incredibly good to deal with and really helpful with any questions.
Once the dials arrive (mine only took a couple weeks) make sure your rifle is zeroed and grab an allen key and swap out the elevation turret being careful to align the markings with your zero.
Practice a bunch, the key to getting confident past 300 yards is really to practice and to have a strong respect not only for your quarry but also for what the wind can do to your projectile.
If you’ve provided accurate data you should be able to range and dial in to targets accurately out to 5-600 yards.
If the conditions aren’t perfect or you haven’t practiced enough to be 100% confident then pull your head in.