… HOW TO MAKE DENSITY ALTITUDE RANGE CARDS We previously covered the APPLIED BALLISTICS PHONE APP. Make sure you read through that article as this serves as a PART 2. Lets dig into how you transfer your cell phone range card to paper. Lets open this up by saying that there are a number of variables that can make your algorithm be slightly off. Were going to cover some of those and show you exactly how to run a basic dope card that is as accurate as a Kestrel and gets you hits on steel all day. The biggest thing you need to pay attention to is putting good data into the phone application so you don’t have less than optimal performance. Good data in, is good data out. In the article covering the phone application, what we covered was how to run the app for a sterile data card. Meaning, no wind included into the range card, just a preloaded bullet profile provided by Applied Ballistics, inputting your muzzle velocity, spin drift, zero-range, and choosing your Bullet’s Drag Model. Keeping it very simple because we want a clean starting point for transfer to your “Quarterback Sleeve.”
Some things to consider… When setting up your RANGE STEP SIZE under preferences on the phone app, you should pick a unit that keeps the range card to where you can reach maximum range at whatever venue that you are shooting at on one piece of paper that fits in your Quarterback sleeve. This is so you don’t have to run multiple cards for the same density altitude. If the targets range is between the step size you’re running, split the difference. Don’t overthink this. Generally inside 800 yards, its roughly .1 MILS for every 10 yards. The faster and higher you Bullets BC is this is no longer the case. Keep that in mind. In this picture above, you will notice that it was made with a blank template on EXCEL, and then filled in manually. All that is filled in is the drop in mils with the corelating range in yards. Above I had annotated the specific bullet, muzzle velocity, and cartridge so it was not confused with any other range cards. There is also a reference to the temperature that was the starting point under ENVIRONMENTALS on the phone app so I can reference it later. If you have dramatic temperature swings from your starting point it can change your data a little bit causing slight deviations in DOPE. I set my baseline temperature in my phone app to the average temperature for the time of the year or day. Density Altitude as covered in the previous article is a combination of Barometric pressure, temperature, and humidity all combined into one number. Keeps it easy so as to not needing a bunch of data points.
Make sure you don’t have wind speed set to anything other than “0.” This will cause data deviations because a left-to-right wind drives the projectile down. Right-to-left wind the bullet climbs. We want a sterile card to start. Select DENSITY ALTITUDE, and fill it in with “0” for your first card. You should set the temperature to the general temperature for the day. Then go to your range card in the APP and transfer those numbers to your range card for your quarterback sleeve. Upon completion of your range card with “0” DA, fill in the DA to 1000FT in the APP. Make sure you encompass every possible DA range you will encounter. A safe bet is making 5. DA “0” to DA 4000. For every 1000 FT DA, its the equivalent of 20 FPS muzzle velocity increase. So understanding this, if you run into the scenario of having the range card in your sleeve of DA “0” at 9:00AM, and its now noon, the DA will have more than likely climbed. Using a basic Kestrel, check the DA and pull out the range card that is closest to the current DA. If you have a muzzle velocity increase because temperature stability issues with your ammo, run whatever card is closest to your DOPE. Using the ballistic calibration tool, take a known distance target that you hit. Then apply the DOPE to “calibrate muzzle velocity.” Go up or down a card for every 20FPS muzzle velocity deviation. This ensures that your Data is dead-on all day. This has been proven to work within .1MIL well past 1000 yards.
For this Kestrel 4000NV, it does not function as a ballistics computer. All we need is the DA reading. Check your DA every so often to ensure you’re on the closest card to the actual DA. Round up or down. Generally rounding up will be the best option in the day because the temp is climbing. Round down through the night as the DA drops when the temperature drops.
Here is a water resistant quarterback sleeve for
. Waterproof your range cards with either a lamination machine, or even clear packing tape. Make sure you annotate as much of the parameters so you know what card is displaying what. The ballistic Kestrels run the same algorithm as the the phone. You can trust the data all day as long as you run sterile data. The nice part of these range cards is that they work year round. They also don’t need batteries. As long as you ammo is relatively temp stable, you can true you rifle using the calibrate muzzle velocity on a known distance target, and run whatever card is closest to your data point you are using. The further out the target is, the more accurate its going to be. I would recommend shooting out to your transonic zone. Whatever the DOPE is for the target that is closest to one of your cards, that is the card you run and how you figure out the DA without a Kestrel. This can be a little intimidating at first. Try this out, and if you have any questions make sure you read the -how-to Applied Ballistics Phone app. DA RANGE CARDS
Here is just a quick example of how we run a DA Card with a white board for a stage. The 1A target for example is 630yards. It is between the two numbers on the dope card. So you split the difference. These are a must have for serious competition use. We leave our Quarterback sleeve around our scope bell during transportation. The white boards stays strapped to our buttstocks so they stay with the weapon at all times. Keeps things simple and no matter what happens you have dope for your gun. During matches both of these are attached to my arms at all times. Hope you enjoyed.
For any additional questions in regards to APPLIED BALLISTICS(TM) user interface, checkout their website and content for further resources. For most questions pertaining to their applications or certain terminology, Bryan Litz has done an amazing job breaking things down so it’s very user friendly. Enjoy!