Appendix K
Sniper’s Logbook SNIPER DATA BOOK
3-147. The sniper data book contains a collection of data cards. The sniper uses these cards to record firing results and all elements that have an effect on firing the weapon. This information could include weather conditions or even the sniper’s attitude on a particular day. The sniper can refer to this information later to understand his weapon, the weather effects, and his firing ability on a given day. One of the most important items of information he will record is the cold barrel zero of his weapon. A cold barrel zero refers to the first round fired from the weapon. It is critical that the sniper know this by firing the first round at 200 meters. When the barrel warms up, later shots may begin to group 1 or 2 minutes higher or lower, depending on rifle specifics. Figure 3-27, 3-27, shows a sample sniper data card.
Figure 3-27. Sample of a Sniper's Data Card 3-148. When used properly, the data card will provide the necessary information for initial sight settings at each distance or range. It also provides a basis for analyzing the performance of the sniper and a nd his rifle and is a valuable aid in making bold and accurate sight changes. The most competent sniper would not be able to consistently hit the center of the target if he were unable to analyze his performance or if he had no record of his performance or conditions affecting his firing. ENTRIES
3-149. The three phases in writing information on the data card are before firing , during firing , and after firing . Each phase requires specific data and provides an excellent learning tool for future training. Each sniper should complete the following information for each phase and analyze his performance to stay proficient at all times. Phase I–Before Firing
3-150. Before the sniper fires, he should record the following data: •
•
Range. The distance to the target. Rifle and telescope number. The serial numbers of the rifle and telescope.
•
Date. Date of firing.
•
Ammunition. Type and lot number of ammunition.
•
Light. Amount of light (overcast, clear).
•
Mirage. Whether a mirage can be seen or not (bad, fair, good).
•
•
•
•
Temperature. Temperature on the range. Hour. Time of firing. Light (diagram). Light (diagram). He draws an arrow in the direction the light is shining. Wind. He draws an arrow in the direction that the wind is blowing and records its average velocity and cardinal direction (N, NE, S, SW).
Phase II–During Firing
3-151. The sniper should also record specific data during firing. This information includes the following: •
•
Elevation. Elevation setting used and any correction needed. (For example: The target distance is 600 meters; the sniper sets the elevation dial to 6. The sniper fires and the round hits the target 6 inches low of center. He then adds 1 minute [one click] of elevation.) Windage. Windage setting used and any correction needed. (For example: The sniper fires at a 600 meter target with a windage
setting on 0; the round impacts 15 inches right of center. He will then add 2 1/2 minutes left to the windage dial [L/2 1/2].) •
•
•
•
Shot. The column of information about a particular shot. (For example: Column 1 is for the first round; column 10 is for the tenth round.) Wind. Windage used. (For example: L/2, 1/2, O, R/1/2.) This is for iron sights or compensation for spin drift. Mil holds are used for the scope. Call. Where the aiming point was when the weapon fired. Large silhouette or target representation. Used to record the exact impact of the round on the target. This is recorded by writing the shot’s number on the large silhouette that is in the same place it hit the target.
Phase III–After Firing
3-152. The sniper also records data after firing that will enable him to better understand his results and to improve his performance. This data includes: •
•
•
Comments about the weapon, firing conditions (time allowed for fire), or his condition (nervous, felt bad, felt good). Corrected no-wind zero. Show the elevation and windage in minutes and clicks that was correct for this position and distance under no-wind conditions. Remarks. Note any equipment, performance, weather conditions, or range conditions that had a good or bad effect on the firing results.
ANALYSIS
3-153. When the sniper leaves the firing line, he compares weather conditions to the information needed to hit the POA or POI. Since he fires in all types of weather conditions, he must be aware of temperature, light, mirage, and wind. He must also consider the following possibilities: •
Compare sight settings with previous firing sessions. If the sniper always has to fine-tune for windage or elevation, there is a chance he needs a sight change (slip a scale).
•
•
•
Compare the ammunition by lot number for the best rifle and ammunition combination. Compare all groups fired under each condition. Check the low and high shots as well as those to the left and the right of the main group. Of course, less dispersion is desired. If groups are tight, they are easily moved to the center of the target; if scattered, there is a problem. Check the telescope focus and ensure that the rifle is cleaned correctly. Remarks in the data book will also help. Make corrections. Record corrections in the data book, such as position and sight adjustment information, to ensure retention. The sniper should compare hits to calls. If they agree, the result is an indication that the zero is correct and that any compensation for the effects of the weather is correct. If the calls and hits are consistently out of the target, sight adjustment or more position and trigger control work is necessary.
3-154. The sniper should compare the weather conditions and location of the groups on the latest data sheet to previous data sheets to determine how much and in which direction the sights should be moved to compensate for the weather conditions. If better results are obtained with a different sight picture under an unusual light condition, he should use this sight picture whenever firing under that particular light condition. A different sight picture may necessitate adjusting the sights. After establishing how much to compensate for the effects of weather or which sight picture works best under various light conditions, the sniper should commit this information to memory. 3-155. The sniper should keep the training and zeroing data sheets for future reference. Rather than carry the firing data sheets during sniper training exercises or combat, he can carry or tape on his weapon stock a list of the elevation and windage zeros at various ranges. Nine Steps for a First-Shot Hit 1.
Determine the range in meters—set. Take slope into account.
2.
Determine the base wind:
a.
In MOA—set. (For iron sights only) or,
b.
Mils for hold-off. 1 mil = 3.5 MOAs, 1/4 mil = .87 MOA, 1/2 mil = 1.75 MOAs, 3/4 mils = 2.62 MOAs.
NOTE:When determining base winds, ensure you know how the mirage looks under the base condition so you can see changes. 3.
4.
Determine the spin drift correction:
a.
600–700 mils left 1/2 MOA.
b.
800–900 mils left 3/4 MOA.
c.
1,000 mils left 1 MOA (M118).
Determine the temperature change from "0" and set: 100–500 mils +/– 20 degrees = +/– 1 MOA.
a.
600–900 mils +/– 15 degrees = +/– 1 MOA.
b.
1,000 mils +/– 10 degrees = +/– 1 MOA.
5.
Determine the pressure change versus "0" pressure and set.
6.
Determine the altitude change from "0" and set.
7.
Determine lead (if a moving target).
8.
Assume a good position:
9.
a.
Bone support.
b.
Muscular relaxation.
c.
Natural POA on the aiming point.
Fire the shot:
a.
Natural respiratory pause.
b.
Focus on the front sight/reticle.
c.
Follow-through.
NOTE:Ammunition should remain covered so it will stay at a constant temperature. As a weapon heats up it will string rounds high. This is caused by the internal residual heat increasing the chamber temperature that causes increased chamber pressure. This increase results in increased bullet velocity. Log all shots and subsequent changes. Wind Data 1.
2.
Determine direction of—
a.
Average wind.
b.
Gusts
c.
Lulls.
Determine velocity of—
a.
Average wind.
b.
Gusts.
c.
Lulls.
3.
Determine mil hold for wind call.
4.
Observer must be prepared to change his wind call based on gust or lulls. NOTE:Lulls are more dangerous than gusts.
5.
Refer to your target dimensions in MOAs:
a.
Center = center of target.
b.
Favor = 1/2 between midline and edge of target.
c.
Hold = the edge of the target.
NOTE:You cannot use mirage as a velocity indicator until you know what it looks like for the average wind. This number will change throughout the day. 8.
Shoot the condition. Do not chase spotters.
9.
Ignore minor fluctuations. Wait for the condition to fully change. Mirage will change before conditions arrive. Boiling mirage indicates change.
10. Grass
will give magnitude of the wind but requires practice for direction or velocity.
11. Observer
computes correction in minutesand gives it to the shooter in milhold-
off. NOTE:This matrix (Figure K-1) is designed to compile data on the individual sniper weapon system’s zero at these ranges and temperatures. Figure K-2, provides sample components of the SOTIC Shooter’s Log as used in the course.
CONSOLIDATED ZERO DATA Meters
100
200
300
400
500
600
700
800
Temperature 50 55 60 65 70 75 80 85 90 95 Figure K-1. Individual SWS’s Data for Zeroing
900
1,000
Figure K-2. SOTIC Shooter’s Log Figure K-2. SOTIC Shooter’s Log (Continued)
Figure K-2. SOTIC Shooter’s Log (Continued)
Figure K-2. SOTIC Shooter’s Log (Continued)
Figure K-2. SOTIC Shooter’s Log (Continued)
Figure K-2. SOTIC Shooter’s Log (Continued)
Figure K-2. SOTIC Shooter’s Log (Continued)
Figure K-2. SOTIC Shooter’s Log (Continued)
Figure K-2. SOTIC Shooter’s Log (Continued)
Figure K-2. SOTIC Shooter’s Log (Continued)
Figure K-2. SOTIC Shooter’s Log (Continued)
Figure K-2. SOTIC Shooter’s Log (Continued)
Figure K-2. SOTIC Shooter’s Log (Continued)
Figure K-2. SOTIC Shooter’s Log (Continued)
Figure K-2. SOTIC Shooter’s Log (Continued)
Figure K-2. SOTIC Shooter’s Log (Continued)
Figure K-2. SOTIC Shooter’s Log (Continued)
Figure K-2. SOTIC Shooter's Log (Continued)
Figure K-2. SOTIC Shooter’s Log (Continued)
Figure K-2. SOTIC Shooter’s Log (Continued)
Figure K-2. SOTIC Shooter’s Log (Continued)
Figure K-2. SOTIC Shooter’s Log (Continued)
Figure K-2. SOTIC Shooter’s Log (Continued)
Figure K-2. SOTIC Shooter’s Log (Continued)
Figure K-2. SOTIC Shooter’s Log (Continued)
Figure K-2. SOTIC Shooter’s Log (Continued) Figure K-2. SOTIC Shooter’s Log (Continued) Figure K-2. SOTIC Shooter’s Log (Continued)
Figure K-2. SOTIC Shooter’s Log (Continued)
Figure K-2. SOTIC Shooter’s Log (Continued)
Figure K-2. SOTIC Shooter’s Log (Continued)
Figure K-2. SOTIC Shooter’s Log (Continued)
Figure K-2. SOTIC Shooter’s Log (Continued)
Figure K-2. SOTIC Shooter’s Log (Continued)
Figure K-2. SOTIC Shooter’s Log (Continued) Downloadable Files
