MEASUREMENT METHOD FOR IN-FLIGHT YAW OF C77 ROUND FINAL REPORT

Transcription

1 MEASUREMENT METHOD FOR IN-FLIGHT YAW OF C77 ROUND FINAL REPORT André Bernier, Vincent Rémillard General Dynamics Canada Ltd. 5, Montée des Arsenaux Le Gardeur (Québec) Canada J5Z 2P4 Phone: (450) Fax: (450) Contract No. W /001/QCV Task 7 (PO92644NG) GD-OTS Canada Project #: GD-OTS Canada Contract No. O.O.4420 Call up 7 Contract Scientific Authority: François Lesage (418) Ext.: 4447 The scientific or technical validity of this Contract Report is entirely the responsibility of the contractor and the contents do not necessarily have the approval or endorsement of Defence R&D Canada. Defence R&D Canada Valcartier Contract Report DRDC Valcartier CR October 2009

2

3 5, Montée des Arsenaux Le Gardeur (Québec) Canada J5Z 2P4 Phone: (450) Fax: (450) DRDC Valcartier CR GD-OTS Canada Project #: Copy #: 1 MEASUREMENT METHOD FOR IN-FLIGHT YAW OF C77 ROUND FINAL REPORT Prepared by: André Bernier Vincent Rémillard Small & Medium Caliber Development & Technologies Presented to: Defence Research and Development Canada - Valcartier Recherche et Développement pour la Défense Canada Valcartier 2459, boul. Pie-XI Nord, Québec, CANADA Scientific Authority: Mr. François Lesage Approved by: Ms. Nathalie Maher Manager Development & Technologies October 27, 2009 W /001/QCV Task 7 (PO92644NG) Client Contrat / Customer Contract No. O.O.4420 Call up 7 GD-OTS Canada Contrat / Contract No. L entrepreneur est seul responsable de la validité scientifique ou technique de ce rapport de contrat et son contenu n a pas nécessairement reçu l approbation ou l appui de R et D pour la Défense Canada. The scientific or technical validity of this Contract Report is entirely the responsibility of the Contractor and the contents do not necessarily have the approval or endorsement of Defence R&D Canada. Rapport Final_801.doc

4 Her Majesty the Queen in Right of Canada, as represented by the Minister of National Defence, (2009) Rapport Final_801.doc

5 EXECUTIVE SUMMARY The angle of attack of a projectile when it hits a target has a major influence on wound ballistics. The higher the angle of attack, the more effect the projectile will have. Small arms rifle rounds, such as the 5.56 mm C77, are spin stabilized and exhibits a very complex flight path due to precession and nutation motions. The details of the motion are not necessary to understand effect on lethality, although critical for understanding aerodynamic behaviour. Although the 3D motion is complicated, a simpler plot is generated when looking at the total angle of attack (alpha bar or simply yaw ). The yaw is zero at shot exit since the shot is aligned with the gun barrel; it reaches a first maximum at about 1 m from the muzzle; then goes through a damped cyclic motion with a wavelength of about 2 m. The wavelength is essentially prescribed by the inertial properties of the bullet and its pitching moment and should not therefore vary much from round to round. What will vary more substantially from round to round (and from gun to gun) is the magnitude of the first maximum yaw which results from the in-bore dynamics and shot release. The lethality will be most affected as a function of range for the first 60 m. In this region, the angle of attack varies from maximum to nearly zero every meter of flight. The difference in target range between a thru-and-thru and a major wound could therefore be one meter. The objective of this project is to develop an experimental procedure to measure the yaw of the 5.56 mm C77 cartridge at approximately 5 m from the gun muzzle when fired from an accuracy barrel and a C7A2 rifle. Two different methods using Nikon and Sensicam cameras were investigated through this program. The Sensicam camera was selected as the best possible method to measure the yaw near the gun muzzle. The yaw was measured from an accuracy barrel and a C7A2 rifle mounted on a fixed stand. The results have shown that the yaw was almost doubled in the weapon compared to the accuracy barrel but remains low. Rapport Final_801.doc

6 RÉSUMÉ Deux méthodes différentes utilisant une caméra Nikon et une Sensicam ont été essayées pour mesurer l angle d un projectile 5,56 mm C77 à environ 5 mètres de la bouche du canon lorsque le tir provient d un canon de précision et d une arme C7A2 montée sur un support fixe. La méthode utilisant une caméra Sensicam a été sélectionnée comme étant celle qui demandait le moins d investissement et qui donnait une meilleure qualité d image du projectile et de la ligne de feu représentée par le papier témoin quadrillé. Un support permettant de fixer les caméras a été fabriqué afin de mesurer l angle d attaque du projectile sur un plan horizontal et vertical à 90. Les résultats ont montré que l angle mesuré à partir de l arme était deux fois plus grand que l angle mesuré à partir du canon de précision. ABSTRACT Two different methods using a Nikon and a Sensicam camera were investigated to measure the yaw of the 5.56 mm C77 cartridge at approximately 5 m from the gun muzzle when fired from an accuracy barrel and a C7A2 rifle program. The Sensicam camera was selected as the best possible method because no investment was necessary and the quality of the image of the projectile and the line of fire of the witness grid sheet was better defined with this camera. A table that supports both cameras was fabricated in order to measure the in-flight yaw of the projectile in the horizontal and the vertical plane at 90 apart. The yaw was measured from an accuracy barrel and a C7A2 rifle mounted on a fixed stand. The results have shown that the inflight yaw of the projectile when fired from the weapon was almost doubled compared to the one originating from the accuracy barrel. Rapport Final_801.doc

7 TABLE OF CONTENTS TABLE OF CONTENTS...i LIST OF TABLES...ii LIST OF FIGURES...iii LIST OF SYMBOLS...iv LIST OF ANNEXES...v 1. INTRODUCTION EXPERIMENTAL TEST SET UP IN-FLIGHT YAW ESTIMATION RESULTS ERROR ESTIMATION TRAJECTORY ANGLE ERROR ERROR ON PHOTOGRAPH ANALYSIS TOTAL ERROR CONCLUSIONS RECOMMENDATIONS REFERENCES DISTRIBUTION LIST...11 Rapport Final_801.doc i

8 LIST OF TABLES Table I Test plan...5 Table II Measured Yaw (Accuracy Barrel)...7 Table III Measured Yaw (C7A2 Rifle)...8 Rapport Final_801.doc ii

9 LIST OF FIGURES Figure 1 Experimental Test Setup...2 Figure 2 Accuracy barrel mounted on a fixed stand...3 Figure 3 Photograph of C77 Projectile at 4.2 m with both types of cameras...3 Figure 4 Experimental Test Setup...4 Figure 5 Weapon Mounted on the 1980 NATO MK2 Stand...5 Figure 6 C77 Projectile at 4.2 m...6 Figure mm C77 Projectile at 4.2 m with a Geometry Measurement Template...7 Figure 8 Sketch of the Setup Alignment with Respect to the Trajectory...9 Rapport Final_801.doc iii

10 LIST OF SYMBOLS α β γ Pitch angle in the vertical plane Yaw angle in the horizontal plane Total angle of attack Rapport Final_801.doc iv

11 LIST OF ANNEXES ANNEXE A - EXPERIMENTAL TEST SET-UP...13 Rapport Final_801.doc v

12

13 1. INTRODUCTION The angle of attack of a projectile when it hits a target has a major influence on wound ballistics. The higher the angle of attack, the more effect the projectile will have. Small arms rifle rounds, such as the C77, are spin stabilized and exhibits a very complex flight path due to precession and nutation motions. The details of the motion are not necessary to understand effect on lethality, although critical for understanding aerodynamic behaviour. Although the 3D motion is complicated, a simpler plot is generated when looking at the total angle of attack (alpha bar or simply yaw ). The yaw is zero at shot exit since the shot is aligned with the gun barrel; it reaches a first maximum at about 1 m from the muzzle; then goes through a damped cyclic motion with a wavelength of about 2 m. The wavelength is essentially prescribed by the inertial properties of the bullet and its pitching moment and should not therefore vary much from round to round. What will vary more substantially from round to round (and from gun to gun) is the magnitude of the first maximum yaw which results from the in-bore dynamics and shot release. The lethality will be most affected as a function of range for the first 60 m. In this region, the angle of attack varies from maximum to nearly zero every meter of flight. The difference in target range between a thru-and-thru and a major wound could therefore be one meter. The objective of this project is to develop an experimental procedure to measure the yaw of the 5.56 mm C77 cartridge at approximately 5 m from the gun muzzle when fired from an accuracy barrel and a C7A2 rifle. The project was defined to meet the following objective: - Obtain an accuracy in the measurement of an angle less than 0.5 compared to the theoretical value when the picture is taken from a fixed projectile; - Select the best possible method to measure the angle of the projectile near the gun muzzle; - Develop an experimental test set up that will allow measuring the yaw at two different angles 90 apart when fired from an accuracy barrel and a C7A2 rifle mounted on a fixed stand and from the shoulder (the latter was cancelled and replaced by adding other barrels in the test); - Estimate the sources of error originating from the test set up and the calculation of the in-flight yaw with the Photoshop software. Rapport Final_801.doc 1

14 2. EXPERIMENTAL TEST SET UP Two different methods available at General Dynamics Ordnance and Tactical Systems Canada Inc. (GD-OTS) have been initially identified to measure the in-flight angle of a projectile. The first method consisted of using a standard Nikon camera with a Pal flash while the other method consisted of using a Sensicam which is currently used at Nicolet to validate the integrity of the projectile during lot proofing. Both methods were identified to give a picture with sufficient high quality to allow for measuring the angle of the projectile with good accuracy at a specific distance near the gun muzzle. It was anticipated that the quality of the image obtained with each of these methods would possibly be of higher quality compared to the shadowgraphs obtained in the Defence Research and Development Canada (DRDC) aeroballistic range. Figure 1 shows a top view of the experimental test setup that was used for both methods to measure the in-flight yaw of the projectile. The cameras were installed at 4.2 m from the gun muzzle. This distance corresponds to a maximum yaw that was estimated by the Army Research Laboratory for the 5.56 mm M855, which is very similar to the C77 projectile (Ref. 1). Break Screen 4.2 m Line of fire (laser) Gun Grid sheet Protective plate Pal Flash and Camera Figure 1 Experimental Test Setup Figure 2 shows how the accuracy barrel was mounted on a fixed stand. Both methods were first tested with only one camera at a specific location to determine which method offers the best possible capability to estimate the in-flight yaw. Both methods showed good quality of the picture of the projectile as shown in Figure 3. It was concluded that the Sensicam solution would be of better interest for three main reasons: Rapport Final_801.doc 2

15 GD-OTS Canada has already two Sensicam cameras and necessary flash spotters to perform the test with two cameras at the same distance; Both the projectile and the lines of the witness grid sheet were better defined with the Sensicam camera as opposed to the Nikon camera from which the lines of the grid sheet were not as well defined; The Nikon camera only works in total darkness which limits its application to a single station and indoor use. Figure 2 Accuracy barrel mounted on a fixed stand A specific table was designed to fix two cameras 90 apart. One camera was positioned to project the projectile on the horizontal plane and the other on the vertical plane. Annex A details the design of the table while Figure 4 shows how the equipment was installed prior to the ballistic test. Only one flash spotter was necessary to give an image with high quality as shown in Figure 3. Nikon Sensicam Figure 3 Photograph of C77 Projectile at 4.2 m with both types of cameras Rapport Final_801.doc 3

16 Rear View Side View Figure 4 Experimental Test Setup The line of fire was defined by using a laser pointer installed inside the barrel during the first trial when there was only one camera. The aiming point of the laser was identified on two paper targets located approximately 0.5m apart. Both aiming points were next projected on the grid sheet to ensure that the sheet is perpendicular to the line of fire and the horizontal lines of the grid sheet are aligned with the line of fire. The first trial was conducted by using a break screen to detect the passage of the projectile. This break screen had to be changed for each round, which increases the time between each round. For the final trial, it was noted that the laser was not perfectly symmetric when installed in the gun barrel as one of its component was damaged when somebody dropped it on the floor. It was thought that this could add another unknown error to the line of fire. A new laser was ordered but was not available during the last trial. A new method based on the trajectory of the C77 projectile was rather used to estimate the line of fire. It consisted of firing a C77 projectile and uses the centers of the bullet holes (entry and exit) made in the witness papers attached to the front and rear of the assembly as shown in the side view of Figure 4. Grid lines drawn on the background sheet were aligned with the bullet holes and thus represent the line of fire. During the last trial, the current screens which are used to measure the velocity at 24 m from the gun muzzle gave similar results as the break screens. Using these screens reduced the time to fire each round within one minute. The lens aperture was set at F16 and the focal distance between the lens extremity and the line of fire was set to 27 in. For this trial, the shutter speed was set at 100 nanoseconds. Rapport Final_801.doc 4

17 Originally, the plan was to fire 10 rounds from an accuracy barrel and 10 rounds from the C7A2 rifle when mounted on a fixed stand. Another 10 additional rounds from a C7A2 when fired from the shoulder was also planned. As the main objective of this project remains to develop an experimental method to measure the in-flight yaw, the test from the shoulder was cancelled because it would have required additional investment to protect the gunner from any fragments that could ricochet to the gunner. This test was rather replaced by adding rounds to the other firing conditions. The final trial was conducted with two accuracy barrels and one C7A2 rifle with three damping settings applied to the fixed stand as shown in Figure 5. Figure 5 Weapon Mounted on the 1980 NATO MK2 Stand Table I gives the quantity of rounds that were fired for each firing conditions that include two different accuracy barrels and one C7A2 rifle with three different damping settings applied to the stand, which has the effect to vary the recoil velocity of the weapon. Table I Test plan Type Barrel # History # of rounds fired Accuracy barrel C7A2 (25,005 rounds fired) ALP ALP AL Approximately 3 to 4 rounds were fired to determine the best position of the flash spotter to obtain the best possible quality of the image. A total of 125 rounds were fired during the final test. Figure 6 shows a typical photograph of the C77 projectile in the vertical plane. As can be seen, the quality of the image is good and we can see the rifling of the gun impinged on the cylindrical portion of the projectile. Rapport Final_801.doc 5

18 Figure 6 C77 Projectile at 4.2 m 3. IN-FLIGHT YAW ESTIMATION The projectile angle is estimated as follows. The black and white image obtained with the Sensicam camera is imported in the Photoshop software. Then a line is drawn inside the software by pointing the cursor on the left side and then on the right side of a horizontal line, which is not actually perfectly horizontal when the image is imported in the software. The lines are forced to become horizontal by rotating the image with the measured angle of the line drawn inside the software. The external shape of the projectile that also includes the symmetry line drawn in a CAD software is next imported and juxtaposed on the projectile image as shown in Figure 7. The projectile from the CAD drawing is then scaled to fit with the geometry of the in-flight projectile image. This was done only for the first round fired in a given group; all the other rounds of the group were so close to each other that it was not necessary to re-scale the projectile template. The projectile geometry template is scaled slightly larger than the projectile image in order to see the whole contour of the projectile image. Then, the tips of the nose of the projectile image and the projectile geometry template are aligned together. The projectile geometry template is next oriented until the space between the ogive and the cylindrical portion of the projectile image and the projectile geometry template is equally distant. Once the template is aligned with the projectile image, a line is drawn with the use of the mouse to point the cursor on the left and right sides of the symmetry line. The measured angle of this line by the software represents the projectile angle with the line of fire. Rapport Final_801.doc 6

19 Figure mm C77 Projectile at 4.2 m with a Geometry Measurement Template 4. RESULTS The final test was conducted in one of the in-house Corridor (#1) at Le Gardeur on October 8, Table II gives the projectile angle as measured at 4.2m. A negative angle indicates a projectile pointing the nose up in the vertical plane (α) and to the right in the horizontal plane (β). A total of 25 rounds were fired for each accuracy barrel but only 10 photographs were analysed by selecting the higher angles in the vertical plane. Both barrels indicate that the projectile was mainly pointing the nose up and to the right at 4.2 m from the gun muzzle. The total angle of attack (γ) was very low and similar for both barrels. It varied between 0.1 and 2.0. Table II Measured Yaw (Accuracy Barrel) Barrel # 1930 Barrel #1929 α ( ) β ( ) γ( ) α ( ) β ( ) γ( ) 0,6 0,1 0,6-0,1-0,8 0,8-1,0-0,7 1,2-0,9-1,0 1,3-0,8-0,8 1,1-0,1-1,5 1,5 0,6-0,3 0,7 0,5-0,5 0,7-0,5-0,4 0,6-0,5 0,1 0,5-0,4-0,2 0,4-0,3 0,1 0,3-0,5-0,6 0,8-0,4 0,1 0,4-0,1-0,2 0,2-0,2-0,6 0,6-0,9-1,8 2,0 0,1-0,3 0,3-0,1-0,1 0,1 0,3 0,1 0,3 Rapport Final_801.doc 7

20 Table III gives the projectile angle as measured at 4.2 m for the C7A2 rifle. As explained previously, the weapon was fixed to the stand with three different damping settings, which have the effect to vary the recoil velocity. A total of 25 rounds were fired for each firing adjustment but only 10 projectiles (20 photographs) were analysed by selecting the higher angles in the vertical plane. All three firing adjustments indicate that the projectile was mainly pointing the nose up and to the right at 4.2 m from the gun muzzle. The total angle of attack varied between 1.3 and 3.3 for all three different firing configurations and for the 10 rounds analysed. Table III Measured Yaw (C7A2 Rifle) C7A2 rifle Std C7A2 rifle Min C7A2 rifle Max α ( ) β ( ) γ( ) α ( ) β ( ) γ( ) α ( ) β ( ) γ( ) -2,8 0,1 2,80-2,0-0,8 2,15-1,9-1,0 2,15-1,7-0,4 1,75-1,3-0,3 1,33-1,3-0,7 1,48-2,2-0,6 2,28-2,5 0,0 2,50-2,1-1,0 2,33-1,5-1,6 2,19-2,7-0,3 2,72-2,0-0,8 2,15-2,1-0,8 2,25-2,5-0,9 2,66-2,6-2,1 3,34-2,0-2,1 2,90-1,6-1,4 2,13-2,7-0,6 2,77-1,4-0,1 1,40-1,2-0,9 1,50-2,1-0,8 2,25-2,5-1,2 2,77-1,5-1,4 2,05-1,6-0,8 1,79-0,7-2,3 2,40-1,8-1,1 2,11-2,1-1,0 2,33-2,0-1,7 2,62-1,3 1,0 1,64-2,4-1,3 2,73 These results indicate that the total angle of attack measured for the projectiles fired from the weapons are more than twice as much as those obtained when the projectiles are fired from the accuracy barrel. 5. ERROR ESTIMATION Two main sources of error were identified with this test. One error originates from a possible misalignment between the line of fire and the projectile trajectory and the second one comes from the measured angle in the Photo shop software. 5.1 TRAJECTORY ANGLE ERROR Systematic errors were minimized by using a high precision set-up to support the cameras. This set-up perfectly aligns the cameras with their respective background and guarantees that both camera axes are perpendicular. However, the grid sheet that is used to define the line of fire must be aligned manually with respect to the projectile trajectory for every set of test. For this test, the projectile trajectory was assumed to be linear and not vary from shot to shot since the cameras were located very close to the gun muzzle at 4.2m. Typically, standard deviation of dispersion for the 5.56 mm C77 NATO ammunition is less than 200 mm at 550 m (σ 0.02 ). Rapport Final_801.doc 8

21 Alignment of the reference grid with bullet trajectory was done by firing test projectiles. Then, using centers of both bullet holes (entry and exit) made in papers attached to the front and rear of the assembly, squared lines were drawn on the background and the reference grid was aligned to them. Hole centers have been represented in Figure 8 by distances y 1 and y 2. Figure 8 Sketch of the Setup Alignment with Respect to the Trajectory Reference grid was placed on the background to obtain y 1 =y 2. Uncertainties on these measures were evaluated to ±1 mm (for y 1 and y 2). This translates to an angle uncertainty of: 1 ( Δy 1 + Δy2 ) Δθ 1 = sin where L = 610mm is the distance between y 1 and y 2 L 1 (1+ 1) sin 0.19 Δ θ1 = =± 610 We can therefore approximate maximum systematic error caused by the set-up to: ΔӨ 1 = ±0.19 This error of constant size is repeated without fluctuation for a given set of shots if the barrel position remains constant between shots. 5.2 ERROR ON PHOTOGRAPH ANALYSIS The assembly greatly contributes to the image quality. It controls precisely parallaxes and distances. The image produced is sharp and clear, much better than those obtained with radiograph and shadowgraph films. Adobe Photoshop was used for pictures treatment and yaw angle measurement. The software has a measurement uncertainty of ±0.05 corresponding to the half of its smaller graduation (tenth of a degree). This uncertainty is repeated twice; first when the image is re-aligned with the horizontal plane and second, when the angle of the projectile is measured. The total uncertainty is therefore ±0.1. There is also a human factor that can contribute to the total error. Since superposition of a projectile template on the image is needed to accurately measure yaw angle, interpretation made by the person analysing the image produces an error. To evaluate this error, a series of images have been analysed by two people. From that experiment, no more than ±0.1 angle variation Rapport Final_801.doc 9

22 was observed at all times. Attempts to reduce uncertainty were made by using different templates. Templates representing a projection of the projectile with 1, 2 3, 4, 5, and 6 degrees of yaw were tried without any improvement on precision. Different colors were also tried and yellow was adopted for its high contrast with the black and white photograph. Taking these two factors into account, the maximum total random error from image analysis is therefore approximated to ± TOTAL ERROR Yaw measurement made with this method gives results with an uncertainty of more or less = 0.39 in each plane. It is to be noted that the uncertainty is usually larger than the error which is impossible to know exactly. Total angle is given by: 1 2 γ = tan tan α + tan For small angles, the uncertainty on γ is therefore equal to ±0.55. The uncertainty is normally given with one significant number; maximum error therefore becomes ±0.6. It would be possible to reduce the uncertainty by using a longer set-up and a more precise way to position reference grid with respect to trajectory. This would minimize: 6. CONCLUSIONS Δθ = sin ( Δy 1 + Δy2 ) L We have successfully designed and fabricated an experimental test set-up that measures the yaw of a 5.56 mm projectile in the horizontal and vertical planes at a distance near the gun muzzle. This experimental method uses two Sensicam cameras that are located 90 apart. The yaw was measured by importing the photographs in the Photo shop software and juxtaposed the drawing template over the photograph. This method has shown to give a maximum error of less than 0.5 with a fixed projectile from which the yaw was known and could be compared with the measured value and thus meet the objective of the project. However, the additional error originating from the experimental setup has been estimated to possibly increase the total error up to 0.6 for the in-flight projectile. Additional work has been identified in the following section to determine if this error can be reduced. β Rapport Final_801.doc 10

23 The yaw measurement has clearly showed that the yaw is higher when the projectile is fired from the C7A2 weapon mounted on a fixed stand compared to the yaw measured from the accuracy barrel. 7. RECOMMENDATIONS The following recommendations are suggested for the next phase to improve the experimental method and reduce the error of the yaw measurement. Validate the accuracy obtained with the new laser pointer to define the line of fire and compare its accuracy with the trajectory of the projectile; Validate if the equipment that is used to monitor the impact points for measuring accuracy of proofing lot could improve the yaw measurement compared to the one obtained with the Photoshop software; Validate if the angle of a projectile when fired from the shoulder is higher than the one obtained with the C7A2 fired from a fixed mount. 8. REFERENCES A) Ehlers, Tyler E., Guidos, Bernard J. and Webb, David W., "Small-Caliber Projectile Target Impact Angle Determined from Close Proximity Radiographs", ARL-TR-3943, U.S. Army Research Laboratory, October DISTRIBUTION LIST EXTERNAL File Mr. François Lesage RDDC Valcartier (Copy no. 1 to 10) and two electronics copies. Rapport Final_801.doc 11

24

25 ANNEX A - EXPERIMENTAL TEST SET-UP Rapport Final_801.doc 13

26

27 Measurement Method for In-flight Yaw of C77 Round Rapport Final_801.doc 15

28

29 UNCLASSIFIED SECURITY CLASSIFICATION OF FORM (Highest Classification of Title, Abstract, Keywords) DOCUMENT CONTROL DATA 1. ORIGINATOR (name and address) General Dynamics, Ordnance and Tactical Systems - Canada 5, montée des Arsenaux Le Gardeur (Québec) Canada J5Z 2P4 2. SECURITY CLASSIFICATION (Including special warning terms if applicable) 3. TITLE (Its classification should be indicated by the appropriate abbreviation (S, C, R or U) MEASUREMENT METHOD FOR IN-FLIGHT YAW OF C77 ROUND/ (U) 4. AUTHORS (Last name, first name, middle initial. If military, show rank, e.g. Doe, Maj. John E.) Bernier, André Rémillard, Vincent 5. DATE OF PUBLICATION (month and year) November a. NO. OF PAGES 32 6b.NO. OF REFERENCES 1 7. DESCRIPTIVE NOTES (the categor y of the document, e.g. technical report, technical note or memora ndum. Give the inclusive dates when a specific reporting period is covered.) Contract Report 8. SPONSORING ACTIVITY (name and address) DRDC Valcartier 2459 Pie-XI Blvd North Québec, Québec G3J 1X5 9a. P ROJECT OR GRANT NO. (P lease specif y whether pr oject o r grant) 12qp03 10a. ORIGINATOR S DOCUMENT NUMBER DRDC Valcartier CR b. CONTRACT NO. W / /001/QCV Task 7 10b. OTHER DOCUMENT NOS N/A 11. DOCUMENT AVAILABILITY (any limitations on further dissemination of the document, other than those imposed by security classification) Unlimited distribution Restricted to contractors in approved countries (specify) Restricted to Canadian contractors (with need-to-know) Restricted to Government (with need-to-know) Restricted to Defense departments Others 12. DO CUMENT ANNO UNCEMENT (an y limitat ion to the bib liographic announc ement of this document. This w ill normally correspond to th e Document Availability (11). Ho wever, where further distribution (be yond the audience specified in 11) is possible, a wider announcement audience may be selected.) Unlimited UNCLASSIFIED SECURITY CLASSIFICATION OF FORM (Highest Classification of Title, Abstract, Keywords) dcd03e rev.( )

30 UNCLASSIFIED SECURITY CLASSIFICATION OF FORM (Highest Classification of Title, Abstract, Keywords) 13. ABSTRACT (a brief and factual summary of the document. It may also appear elsewhere in the body of the document itself. It is h ighly desirable that the abstract of classified documents be unclassified. E ach paragraph o f the abstract sh all begin with an indication of the securit y classification of the information in the parag raph (unless the document itself is unclassif ied) represented as (S), (C), (R), or (U). It is not necessar y to include here abstracts in both official languages unless the text is bilingual). Two different methods using a Nikon and a Sensicam camera w ere investigated t o measure the yaw of the 5.56 m m C77 c artridge at a pproximately 5 m from the gun muzzle when fired from an accuracy barrel and a C7A2 rifle program. The S ensicam camera was selected as the best possi ble method becaus e no invest ment was necessary and the quality of the image of t he projecti le and the line of fire of the witness grid sheet was better defined with th is camera. A table that supports both cameras was fabricated in order to measure t he in-flight yaw of the projectile in the horizontal and the v ertical plane at 90º apart. The yaw was measured from an accuracy barrel and a C7A2 rifle mounted on a fixed stand. The results have shown that the in-flight yaw of the projectile when fired from the weapon was almost doubled compared to the one originating from the accuracy barrel. 14. KEYWORDS, DESCRIPTORS or IDENTIFIERS (technically meaningful terms or short phrases that characterize a document and could be helpful in cata loguing the docum ent. The y should be selected so t hat no security c lassification is re quired. Identifiers, such as equipment model des ignation, trade name, military project code name, geogra phic location may also be included. If possible keywords should be selected from a publis hed thesaurus, e.g. Thesaurus of Engineering and Scientific Terms (TEST ) a nd that thesaur us-identified. If it is not po ssible to sele ct ind exing terms which are Unclassif classification of each should be indicated as with the title.) yaw small arm small caliber flight in-flight C77 camera weapon projectile experimental line of fire ied, the UNCLASSIFIED SECURITY CLASSIFICATION OF FORM (Highest Classification of Title, Abstract, Keywords) dcd03e rev.( )

31

32 Defence R&D Canada Canada s Leader in Defence and National Security Science and Technology R & D pour la défense Canada Chef de file au Canada en matière de science et de technologie pour la défense et la sécurité nationale