Hello,
In order to improve my accuracy and shooting, I have read and learned how important it is to keep a data book to provide historical / trending of various conditions and shots to make adjustments in the way that we shoot. I am not very familiar with these at all - including how to properly record one.
Here is a link to a USMC Data Book that I found online. Does this look like what is being used now?
http://www.inlex.net/feck/RiflemansDataBook.PDF
No, that is not the current data book for the M16.
The data books are revised to reflect the weapon and targets in use at the time, and for the type of shooting (annual requalification or competitive matches.) The link you provided for the '78 version is titled "Competitive Rifleman's.." This data book was intended to be used in match competition as opposed to annual requal. In '78 Marines were still shooting the M14 in matches, and that is how this book is set up- for an M14, shooting M72 match ammo, and using the standard 10x targets for National Matches.
There are many different styles of data books, and you should find one that is set up the way you like, but most importantly, the data book should match the type of rifle (and sights) and the type of targets you are shooting. They all incorporate the same basic info, just arranged differently.
We won't get much further here without discussing MOA. I don't know how much experience you have in shooting, maybe you already understand MOA, But I'll run through it here just in case.
A minute of angle ("MOA") is just a simple unit from geometry. There are 360 dgrees in a circle (most people know this...). So you can measure pieces of a circle in degrees- as in, "Right turn Clyde." A right turn on a city street would be 90 degrees, and a u-turn would be 180 degrees. Again, most people know this, but... So a 1 degree angle is very small.
Suppose you want to measure a very, very small angle that is less than 1 degree? For this, a degree is split into 60 slices, and each slice is called a "Minute." There are 60 minutes in one degree, so a single minute is 1/60th of a degree. This is a minute of angle, or "MOA." the MOA turns out to be very useful for precision measurements, as in shooting a rifle.
The important thing to understand about an MOA is that it is an angle, not a fixed distance.
To picture an MOA, imagine that you painted a straight line on the ground from your rifle to your target. Then you painted another line on the ground starting at you rifle, but angling away from the first line slightly, at an angle of 1 MOA (1/60th of 1 degree.) If you stopped at 100 yards, and measured the distance between the two lines, they would be 1" apart. (Actually 1.047 inches, but the .047 is so small that everyone just ignores it and calls it an inch.) If you kept on painting out to 200 yards, the lines would now be 2" apart, at 300 yards, they would be 3" apart, at 500 yards 5" apart, etc.
This is a happy coincidence, and is so easy to use that all rifle sight and scope adjustments are discussed in MOA.
If a certain rifle has sights that are set up to adjust 1 MOA per click, then 1 click will move the strike of the round 1" at 100 yards, or 2" at 200 yards, or 3" at 300 yards, etc.
You must know what type of sights are on your rifle. The M16A1 had sights that moved 1 MOA per click, as did the M14 rifle, the M1 Garand, and lots of others. The M16A2 rifle was issued with sights that moved 1/2 MOA per click for windage and 1 MOA per click for elevation on the rear sight, but the front sight moves 1-1/4 MOA per click. (Confused yet? If so, you're not alone...) 1 MOA is a pretty big adjustment on a precision rifle, so for competition, most match rifles will have special sights that move 1/2 MOA per click or even 1/4 MOA per click. With 1/2 MOA sights, 1 click will move the bullet 1 inch at 200 yards (1 MOA at 200 yards=2 inches, so 1/2 MOA is one half that- 1 inch.)
The important thing is to know how your sights are set up.
Back to the data book.
On the 200 yard slow fire page, you will notice small numbers printed across the top and sides of the picture of the target, with grid lines. These numbers are used to measure how far off your shot is, so that you know how far to adjust your sights to get in the center.
In the book you linked to, these numbers are 1 MOA adjustments. You can confirm this by noting that the 9 ring of the S-R target is 13" wide (see the dimensions on page 3) but on the 200 yard plotting page, the 9 ring is 6-1/2 "numbers" wide. from the above MOA math, we know that 6-1/2 MOA=13 inches at 200 yards.
So if your rifle has 1 MOA sights, these small numbers are equal to "Clicks" on your sights. If you have anything other than 1 MOA sights, then you need to convert in your head.
Example: Assume that you are shooting a standard M16/AR15A2, with 1/2 MOA windage and 1 MOA elevation sights. You fire a good shot at 200 yards on the S-R target, and the shot lands exactly on the edge of the 10 ring at 9:00. You plot the shot on the plotting sheet, and then trace up on the page and see that your shot, at the left edge of the 10 ring, is just a hair less than 2 MOA left. So, knowing that your sights move 1/2 MOA per click, you do some quick math in your head and figure that 2 MOA=4 clicks. You move your rear sight 4 clicks to the right and your next shot is dead center in the x ring.
Suppose your shot lands at the bottom edge of the 10 ring. Tracing across, you again see that your shot is 2 MOA low, and knowing that your sights are 1 MOA per click for elevation, 2 MOA=2 clicks. So you come up 2 clicks on the rear sight and your next shot lands dead center.
Most data books will show those little numbers in MOA. That way, knowing your own sights, you can calculate good sight adjustments for any rifle.
The current Marine Corps data books are set up specifically for the M16A2 though. They have already made the corrections for the potentially confusing 1/2 MOA x 1 MOA M16A2 sights. So the little numbers are twice as big across the top as they are along the sides on the data book page. This makes the numbers work directly in clicks for the A2 sights, relieving the Marine from having to remember which is which and making the correction in his/her head. (Is that cheating? Hmmm....
OK, enough on MOA.
As an example, I am interested currently in a Slow Fire at 200 yrds. This would be on Page 5 of the book.
If some of you who are shooting rifle experts with experience wouldn't mind taking the time to explain & educate this to me - or maybe someone else in this forum can find this information helpful too by your answers, I know that it would really help benefit me to serious accurate shooting. Would it be possible for someone to briefly go through each column to explain it and what type of value should be documented into that (box) or column. I will attempt to take a quick stab as to what I think some of these mean - please correct me where wrong. Some of these I am not even sure about at all.
Looking at the Left Side:
*Range,Target No, Rifle No, Date - Self Explanatory.
*Ammunition - Self Explanatory.
Light = I can see this indicating a clock direction where the sun's current position is located for a box marked "Box Direction". But what do you put in the "Light" Box?
Bright sun, hazy, overcast, cloudy, (or even, in military service, twilight or pitch ****** dark...) It makes a difference in your sight adjustments. Your own notes and practice will tell you how much difference it makes for you. The general rule is, "Light's up, sights up."
Mirage = not sure what this is. If I guess, is this where you see possibly a reflective image of the target on the ground at very long distances - 600 - 1000 yrds on hot days?
You have probably seen mirage on a hot highway during the day. That is an extreme example. In competition shooting you will normally have a spotting telescope set up next to you on the firing line. A lot of the time on a rifle range, if you look through your spotting scope towards the targets and adjust the focus of the scope so that you are focused 1/2 to 2/3 of the way out to the target, you will be able to see a mirage coming up off of the grass or dirt on the range. The wind will make the mirage clearly stream off to one side or the other, or if there is no wind at all the mirage will appear to boil straight up. This is very useful as a fine tuning aid to your estimate of the wind. During a string of slow fire, you check through the scope between each shot and observe the mirage. If you are hitting dead center, and the mirage looks exactly like it did for the last shot, then you go ahead and shoot again. If the mirage looks different, then you can either wait until it looks the same again and then shoot, or make a windage adjustment for the change and then shoot. In the "mirage" box on the page, just go ahead and use your artistic talents and draw some little squiggly lines of what the mirage looks like to you through your scope. Over time and with practice, you will be able to translate mirage into sight settings.
*Temp, Houre = Self Explanatory.
Sight Picture = Is something drawn or pen-marked as how sight picture looks with current sight alignment?\
There are different ways to use your sight picture, and everyone has their own preference. In combat, you normally set your sights so that the bullet hits exactly where the tip of the front sight post is. This is called "point of aim-point of impact." For competition, the important thing is to use a sight picture that lets you clearly see that it is exactly the same every time. Where the front sight tip ends up is not important, as long as YOU can do it exactly the same every time. The most popular is the "6:00 hold," where you make the front sight tip just touch the bottom of the black bullseye for each shot. Then there is the "line of white" hold, where you let just a little tiny sliver of white target paper show between the front sight tip and the black bull, the "flat tire" hold, where you hold the front sight tip just a bit into the bottom of the black so the bullseye looks like a flat tire on top of the sight, the "center mass" hold which is where you try to hold the front sight tip exactly in the center of the black bullseye each shot- same as "point of aim-point of impact," I have even heard of people holding the front sight tip on the target frame. You can adjust your sights for any of these, the important thing is that it works for you and you can do it exactly the same every time.
In this box, again use your artistic talents and draw a picture of the front sight tip as you used it for that string of fire. If you are experimenting with different sight pictures, then later you won't have any idea what happened unless you fill this in.
Wind = Mark direction and write a value of estimated speed - either by detection of wind flag angle or observation method.
Look at the flags, toss a few blades of grass, blow some cigarette smoke, beg other shooters, beseech the gods, and get your best estimate. Then hold up your hand-held wind meter and find out how far off you were. Write it in this box.
Moving on down:
In the No row: (SS) is shown 2 times and grayed out- what does that indicate?
SS=sighter shots. In some matches you are allowed 2 free shots to check your sights and wind estimate. Grayed out because they don't count on your score.
Elev = This would be my elevation setting on the rifle.
Yes, the ACTUAL elevation you used for that shot. This may be different than your zero if it is a really hot day, really cold, you are shooting at a range at higher or lower altitude than you got your zero at, the light is brighter or darker than usual, etc.
Say you get a good zero on your rifle at 60 deg. F. Then you are shooting some day at 90 deg f., and you notice that your first 2 or 3 shots hit a little high. So you come down a click on your sight and you are right in there. This is where those adjustments are recorded for reference for all time. The next time you are shooting on a hot day, you can look back in your data book and know that you need to come down 1 click to adjust for the temperature.
W.G. = I assume this is the windage setting on the rifle?
Yes, your ACTUAL windage setting for that shot. On a gusting windy day your windage setting might be different for each shot. You use this to learn how to correct for wind. You can look back at each wind correction, see where the shot landed and compare it to the adjustment you made. If you pay attention, you can teach yourself how to adjust for the wind very accurately. Did I adjust too much, not enough? Oh, but wait, what bullet weight was I shooiting that day? (of course you have that recorded also...)
Call = Not sure what that what means or what to mark here.
Calling your shots is everything. This is where you learn how to shoot.
After each shot there is a thing called "follow-through." This means that after each shot, you stay absolutely still, holding the trigger back, still concentrating on the front sight tip, for a second or two. If you move immediately after each shot, you are training your brain to expect the movement, and eventually your brain will anticipate this and start moving DURING the shot. This is bad. By following through after every shot, you are training your brain to keep your body still, and you won't twitch and ruin the shot itself. This is good.
While you are relaxing and enjoying a nice follow-through, one of the things you do is take mental snapshot of EXACTLY where the front sight tip was when the shot broke, as well as whether your sight alignment was right, how your position felt, were you relaxed on your natural point of aim, whether you felt out of breath because you folled around with the shot too long without breathing, etc. Take this mental snapshot and make an ABSOLUTELY HONEST estimate of where that bullet actually went. Mark a dot on the little target where you think the bullet landed. Then, check through your spotting scope (if you are practicing alone) or wait for your target to come up with a spotting disk (if you are in a match) and mark the actual bullet impact on the big target picture on the data book page. Just write a very small number (if this was your 9th shot, write a little "9") where the shot hit.
The important thing here is to have an accurate record of where you called the shot, versus where it actually landed. 90% of learning to shoot a rifle well is learning to call your shots accurately. If you can call your shots, then you can start to identify the mistakes that made a shot go off center.
At first, you will tend to call every shot as a center hit, but they will not be. If you pay close attention, with practice, you will start to feel the little mistakes and jerks, and you will be able to say, "That one broke a little low left. About an 8 at 7:00..." And sure enough, when you check the target, it was an 8 at 7:00. When you can do this, you will be well on your way to becoming a good shot.
The data book is a textbook on marksmanship... Except it's blank. You write your own textbook on how to improve your own shooting skills by filling in all the boxes honestly and accurately, and then studying your own notes carefully afterwards.
Value = Where the round hits in the rings - that is the value written in.
Yes- try not to pay too much attention to this while shooting or you will psych yourself out. As the Gambler said, "You never count your money while you're sittin at the table..."
Looking at the Right Side
S-R Target Title = does that mean Short Range Target?
Probably. That's just what they named that target.
Again, we have boxes for Elevation & Windage. Need explanation between the Used-Correct, Zero-Correct boxes since I assume some of this was being recorded at the boxes to the left side of the page?
This for reference later. You fill in the sight settings that you used during that string of fire. Then later, when you review the shots on that page, you fill in what you think you should have done if there is an error you can see. The next time you shoot under the same conditions, you will start with the "correct" numbers from this page. "Correct" = "What I should have used"
Dimensions of the Target
According to this target plot area, the actual target area on the range would be a total of 8" from center to top and 8" from center to bottom for an overall height of 16" from top to bottom. What is on paper should match the dimensions of the target at 200 yrds - correct?
The target is also 8" from center to left and 8" from center to right with an overall width of 16".
The overall width x height of the target as shown on paper is a 16"x16".
Did I interpret that correctly?
See above on MOA. Those are MOA markings for calculating sight adjustments. At 200 yards, 32" from top to bottom.
I appreciate everyone's patience for what I am asking and if it seems elementary - any explanations to properly use this data sheet would be gratefully appreciated.
Thank you,
Steven
Hope this helps. More to come, but right now the neighbor's dogs insist that I show up on the porch for a beer.
What type of AR are you shooting, and what sights does it have?
I have a copy of the (3574) U.S. Marine Corps Rifle Marksmanship and Data Book for U. S. Rifle 5.56-MM, M-16A2, NAVMC 42 (REV 10-91) sitting right here in front of me. There are example pages in the book on how to fill all this stuff out, and if I can get up the energy I might just scan and post those pages here, I think it will help.