Data Management
By Ian Kenney
It has been said that there are millions of gun owners in the world but very few shooters and it’s a statement that I find much truth in. I believe one that one skill that is essential for the true marksman is the collection and utilization of trajectory data for their rifles, otherwise known as “dope”. Dope is actually an acronym that stands for Data On Previous Engagements, which are the elevation and windage settings necessary to get hits on target at a given distance. Some shooters spend hours in the hot sun, in a cold rain, or on a windy mountainside collecting data on each shot so that if he or she is in a similar situation down the road, they know what the round will do. Obtaining this data is only half the battle, since it doesn’t do the shooter any good if the data can’t be accessed when it is needed. There are a number of ways to manage this data and keep it accessible, whether at the range or in the field. These range from simple laminated ballistic cards to thousand-dollar PDA’s w/ integrated ballistic programs that can account for multiple variables.
Data Books
One of the first things a new shooter should learn how to use in order to collect, organize, and access their rifle’s dope is a shooter’s data book. The shooter’s data book is a common item among military and police snipers that is used to track the history of the shooter’s rifle. The data book contains reference sheets and conversion tables as well as pages the sniper can use to enter in different information about how the rifle and ammunition perform in certain weather conditions. All of the information in a shooter’s logbook creates a detailed history of the rifle so that it can be reviewed at a later date or under similar conditions to predict where the bullets will impact. While data books are typically used by military and police shooters, it can also be an effective tool for civilian shooters for all the same reasons.
In today’s market there are a plethora of data books from the simple to the comprehensive, therefore choosing the one that best suites your needs can be a challenge. So far though, I’ve found that the modular, or do-it-yourself, data books usually suit the needs of the civilian shooter, and in some cases professional shooter, better than most other data books. The reason for this is that it allows you to customize the data book to your needs instead of having to deal with a data book that has pages that will never get used. For example, some data books come with wind and trajectory charts that are of no use to the shooter since the data was probably made for a different cartridge in different conditions. Printable/modular data books also offer blank pages so that targets can be drawn to create a better representation of the target instead of just using the shape printed on the paper. A good rifle data book should also have sections for logging your zero summaries, target sizes, pages for your cold bore shot, and a barrel log to track the number of rounds down a barrel. There should also be pages in there with conversion tables and equations for calculating leads and wind hold off, however, these aren’t absolutely necessary, just nice to have.
There are many accessories available for the data book, one such accessory being a nylon cover that has internal pockets for the storage of essentials. These covers are excellent at carrying items like a “slope doper”, Mildot Master, calculator, weather meter, extra pencils, target stencil, and a 6” ruler so that they stay accessible. Those accessories make getting and logging data a snap, however, many items are optional and some can be left out as other items can do double duty. For example, the Mildot Master can be used to calculate distances and measure slope, negating the need for a calculator and a “slope doper” which reduces weight and volume. As for writing in the data book, I prefer to use a cut-down #2 pencil as opposed to a mechanical pencil or ink pen because you can’t sharpen a mechanical pencil with a knife and if the pen runs out of ink or you make a mistake you’re SOL.
The modular data book, mildot master, and sniper template make for an excellent package for the long range shooter, professional and hobbyist alike.
Most data books on the market are generally laid out in pretty much the same way with the conversion tables and equations up front, followed by a target dimension sheet, zero summary sheet, zero targets/cold bore, then the torso targets, range card, field sketch, and a barrel log at the end. This doesn’t mean that when making your data book you have to stick to that template, you should put the data book together in a format that works for you. That being said, however the data book is set up, enter as much data as you can into it so that you will get the most out of it.
Before firing, jot down as much information as you can so you won’t have to go back later or try to do it on the range when you could have multiple things going on. Things that should be filled out prior to firing are the date, time, location, rifle/scope SN, ammunition used, distance, lighting conditions and wind conditions. Altitude, humidity, barometric pressure, average temperature, and mirage can be entered later or prior to firing if you have a handheld weather device. To simplify tracking data in regards to the atmospheric conditions I've started to use density altitude since it is a combination of the above variables that puts things into a single number. This makes it much easier for me to notice trends that will help me build more accurate data cards since I'm not trying to sort through various temperatures, altitudes, and pressures.
When logging the shots, enter in the elevation and windage dope into the proper box as well as the call for the shot. There is some confusion about what to actually put as the call but I like to think of it as one of two things depending on the range to the target and whether or not the shooter holds off. For close range shots or if the shooter dials in the wind correction I'd say that the call is where the reticle was on the target when the shot broke. For shooters that utilize hold off's for distant targets I'd say the call is where there hold off point was on the target when the shot broke. If your wind hold for a 600 yard target is a half mil and just as the shot broke the half mil mark dipped low left, place a mark low left on the call box. To get the most out of the data book don’t log every shot as center mass either but where the shot actually broke. When I mark my shots on the target diagram I place a dot on the target and a line with the corresponding number of the shot coming away from it. The shots can almost be marked with just the shot number placed on the target diagram instead using the dot and line method. Which ever method is used to plot the shots on the data sheet try to be as accurate as possible.
One of the most vitally important pieces of the information for the military or law enforcement shooter as well as to the civilian competitor is the cold bore shot. This is the first shot down the bore and in some cases the only shot a shooter may get so logging and knowing where that first round will go is important. There are two kinds of cold bore shots clean cold bore and dirty cold bore. A clean cold bore shot is the first one taken after a barrel has been cleaned so there isn’t any carbon or copper fouling in the barrel. A dirty cold bore shot taken in between cleaning sessions so there is often carbon and /or copper fouling in the barrel. Depending on the quality of the barrel and its assembly to the action there can be little to no difference in the cold bore shot and the following shots, which is why it is important to track this information. The cold bore data sheet can be filled out in much the same way a regular target data sheet is filled out.
The torso target sheet, as well as the blank data sheets, can be filled out similarly to the cold bore data sheet except more rounds will be plotted and more information will have to be tracked by the shooter.
This is an example of a well filled out data sheet where five rounds were fired at a torso target at 209 yards. In general we can tell from the information provided that it was a cool, sunny day with a light breeze and that the rifle’s cold bore shot was dead on with the other shots. When a data sheet is filled out properly someone should be able to pick it up and know what the shooter was doing and what it was like that day when a particular shot was made.
Another important data sheet, and some say the most important next to the cold bore data, is the barrel log, which keeps track of every shot fired down the bore. The barrel log can also be used to keep track of cleaning cycles.
Once the shooter collects enough data, the zero summary chart can begin to be filled out, which will help to track the elevation adjustments required at different distances and in varying temperatures. A zero summary chart can also be filled out using changes in density altitude instead of temperature differences to account for a wider range of conditions. This data can be used as a quick reference in the field or to make accurate range cards for separate use.
Be sure to use one zero summary chart for one load and another chart for a different load so it doesn’t create any confusion down the road.
Two data book sheets that are probably the least used outside of military and police circles are the range card and field sketch pages. Most shooters will probably never use these however that doesn't mean they are completely useless. I've found the range cards and field sketch sheets to come in handy at competions for plotting multiple targets that are different distances that I know I'll have to come back too.
The range card is typically used by the military in defensive positions so that the soldiers will know what is in front of them even if it is completely dark and they just got into the position. The range card can be used during competitions, or hunts, to mark targets or landmarks for easier ranging. The range card should be filled out in a bird’s eye view format and it is up to the user to draw in topographic features however that is really dependant on their skill level. The user should at least try to be as detailed as possible in both the ranges and descriptions of the objects in their immediate vicinity.
At the top left of the range card is an area to enter the date, location, method in which distances were obtained, direction of view, and the distance format. The range rings can correspond to any distance and is really dependant on the field of view. In this case the trees and the position may have limited their view to about 200 yards. Below the range rings is an area to input the ranges as well as the elevation data so that if a target presents itself the user will have a quick reference on the range necessary to engage it. Below that is a section for hold off, which, would apply if the user has a scope that adjusts in MOA and needs to know the hold offs in mil in case there isn’t enough time to dial in the proper dope. Farther down is a section for any remarks about the area, which, should be as detailed as possible in case it has to be reviewed later on.
The field sketch is essentially a drawing of what the user sees in front of them and should be drawn as such; not as an aerial view. It takes some practice to become good at drawing a field sketch but once done it can be an effective tool for military and civilian shooters alike.
Many data books also come with a sheet for target dimensions that can be referenced for range estimation purposes. It’s generally a good idea to get measurements that are as accurate as possible and of as many objects as possible, which will only aid in getting good range estimates. What to get dimensions of will depend on the shooter’s needs though so not every shooter will need the target dimensions of mailboxes or stop signs.
One thing to consider including in the data book are reticle diagrams that show the sub-tension of different reticles, which can be used as a reference when trying to get accurate range estimates. Additionally, it could be a good idea to include drop charts for rifles that don’t necessarily need data books themselves but could benefit from having some long range dope.
Also handy are range estimation tables that give you the range of an object after choosing the target size or next closest size and its mil reading. These can be pretty accurate but it really should only be used as a quick reference instead of the primary means of gathering the range to a target.
Additionally, don’t be afraid to customize the data book to suite your needs; Make the data book work for you instead of you working around the data book. For example, my modular data book has a heavy plastic cover that flapped open during storage or carrying which caused some items to fall out. To remedy this I took a piece of shock cord, drilled two holes in the bottom cover and pulled the shock cord through so that the cord held the cover closed. I also used file tabs to mark the different sections of the data book, such as target sizes, alpha sheets, torso sheets, range cards, and barrel log. That way in the field I’m not flipping through page after page and I can just go to the tab I’m looking for a flip straight to that section.
An inexpensive option to the modular data book is to use a good quality notebook such as those from Rite-N-The-Rain and while it won’t be perfect it can serve the purpose of jotting down vital information. I’m using this form of “data book” for my AR-15 since I can’t really justify it having its very own modular data book, but I want to record drop data when shooting long range.
I kept the format pretty simple and used page labels to make sections for rifle and scope serial numbers, round count, drop tables, mil hold off, and blank pages for jotting down information on elevation and wind data. I also threw in a homemade target template to help draw some targets in and a calculator to help with range estimation.
Above are some pages from the expedient data book showing the drop table, mil hold off chart, and a blank page marked out showing data for hits on a torso target.
Those are pretty much the basics of the rifle data book and it is up to the user to make it as simple or as complicated as they’d like, depending on their needs and skill level. However you use the data book it should always accompany the rifle to ensure the data is logged accurately or in case a critical piece of data from a previous range trip is needed. There have been times I had to consult my data book to help confirm the range to a target or determine what the elevation and windage settings should be based on previous shooting in similar conditions. Just recently I was at a competition where I successfully used my data book to help obtain the range to a target and come up with the dope needed to hit it. The situation was that I had a time limit to range multiple targets and come up with the dope needed to hit them. One target was difficult to range because the orientation of the target didn’t allow for a good range estimate. I knew the target was near a road I had collected data from on targets that were on the hillside I was shooting from. I got out my data book and consulted the old range card and dope settings. I found the range from the road to the nearest target to me on the hillside and subtracted the estimated distance my intended target below was from the road. After making another correction for the angle I came up with a dope solution and fired, getting a perfect first round hit and qualifying the need to keep old data handy.
Data Cards:
Another method of managing your data is the tried and true data card that can be purchased on the commercial market or they can be simply made right at home. A data card is a laminated piece of paper that has distances in different increments with the corresponding elevation setting and the windage data for a given wind speed. Data cards are normally generated by a ballistic program for an average set of conditions, which should be taken into account whenever using them, especially commercial data cards.
There are several companies that make pre-made data cards for common match loads, and custom data cards or data card sets as well, that cover a variety of atmospheric conditions. Most commercial data cards are for common match loads at average muzzle velocities and generally use atmospheric conditions of 59°F, 0% humidity, and at an elevation of sea level. However, try to use that same data card at 3,000 ft, when it’s 75°F outside, and 60% humidity, the data will probably not do you much good beyond 300 yards. This is not so true for the custom data cards of course but some custom ballistic cards can cost upwards of $40 or more.
This is one reason I prefer to make my own data cards at home using the free online ballistic program called JBM Ballistics, some heavy card stock, and a laminating machine. I can tailor the data card to the conditions I will most often be shooting in, instead of trying to go off of a store bought solution. So far using the online ballistic programs and an average of the conditions I’m most often shooting in, my data has been generally been within just one or two clicks of the elevation knob, if not dead on, of the point of aim. Sometimes the fit and finish isn’t as good as what you would get with some of the commercial options but it will probably be more accurate and a good bit of data can included too. I keep track of the cards by taping them to the side of the stock or by using 550 cord to secure it to the scope’s main tube. Like most things in life, the end product is only as good as the effort that goes into making it. It is no different with data cards, the better the information and effort put into making them, the better they will be.
Flip-Up Cap and Elevation Knobs
Another method of managing data and keeping it handy is to use the underside of the flip-up cap that covers the ocular that most shooters use. Although it is small it can easily accommodate vital DOPE or other data for the shooter to easily look at. I’ve used this method for a few years and I typically use masking tape on the inside of the cap with a mil hold off chart hand drawn inside. There are also commercial solutions available with pre-made tables that allow the shooter to write down specific drop data.
Making a do-it-yourself BDC knob is also an easy way to keep track of drop data in the field should you lose your data card or are one a time limit and need a fast visual reference. This method works best on single turn elevation knobs or knobs that are tall enough to accommodate at least two rows of numbers. I’ve used this technique on S&B single turn knobs with good success by simply writing a yardage value over the corresponding elevation setting on the knob.
There is a commercial option as well from Kenton Industries who will make a custom elevation knob according to data provided to them for a variety of different scopes.
In my opinion making, or using, a BDC knob and keeping some data in the rear flip cap are excellent ways of keeping data handy as a back up should you lose your primary data cards or you need to access the information quickly.
PDA’s with Ballistic Programs
I’m only going to provide a cursory description of these since I don’t have much experience with them personally however they have become a vital component to many long range shooters. This method of managing and accessing data uses a personal data assistant, such as a Palm Pilot, with a compatible ballistic program that can give accurate trajectory data based on the shooter’s current atmospheric conditions. Ballistic PDA’s are often used in conjunction with personal weather stations that can give temperature, humidity, wind speed, or even density altitude readings that can be entered into the ballistic program that will then give the correct elevation and windage settings to get rounds on target. PDA’s with ballistic programs have been in use successfully for quite some time now and some version are currently in use by the US Military.
In The End
There is no doubt there are a multitude of ways for a shooter to collect, organize, and access the data gained from range and field time so that it can be put to good use down the road. The goal of this article was not to cover them all but to provide a good basis for shooters to start from so that they may develop their own skills and techniques in data management. All of these methods have their pros and cons, so the shooter should examine them all and determine which method, or combination of methods, is the best one for them. An important thing to consider though is that whatever method is chosen, keep it simple and easy to use because the more complicated it is the less effective it will be when it really counts.