thedrifter
01-04-04, 10:27 AM
Mortar Gunnery
by CWO3 Jeffrey L. Eby
Mortar gunnery should be a stated task at CAX in order that units spend time ensuring mortar teams are properly trained.
Mortars are outstanding weapons. Yet mortarmen, like most Marines, attempt to attain perfection at the expense of responsiveness. In an effort to “hit” the target, an emphasis is placed on first round precision vice sufficient suppression in a rapid timeframe. The rotation of forces to the Combined Arms Exercise (CAX) at Twentynine Palms may be indirectly part of the problem. We must refocus on what we want from our mortars and ensure our training goals are established to achieve this end.
The reason I blame the CAX for the development of precise, unresponsive mortars is due to the expectation that the first round fired on a hip shoot be “relatively close” to the objective. What is relatively close? That is at the whim of the senior evaluator. In the Mojave Desert a few miles is relatively close by one point of view. To the friendly force subjected to an errant round, 1,000 meters is relatively close. The problem is to identify what relatively close is in the mind of the enemy receiving our fires and train accordingly. I would suppose the enemy is much like us, and an exploding round within 1,000 meters is relatively close. This expectation, coupled with no sense of urgency to fire the first round, drives units to forgo speed. Since the skills of the mortarmen are not a stated goal of the CAX force, no emphasis is placed on meeting minimum time lines to be fire capable (FireCap) after mounting the guns, nor will a delay be taken to teach or recock the attack should the mortars take too long. The idea to be “close enough to be seen and adjusted by the forward observer (FO)” is not an issue, but it should be. The mortarmen appear to be attempting to develop a reputation for being sniper mortars. One shot, one kill was not the intent of mortar gunnery. The only way to alleviate this potential problem is to impose a time limit on hip shoots. This can be done safely with supervision and allows muscle memory to develop for the “right way” to do responsive hip shoots. Failure to meet the time limit forces the unit to recock and attempt the attack again and again and again.
Since the CAX is one of the few areas where units have the room to do a movement to contact hip shoot, the experience learned from this exercise will eventually override all other instruction and become “the way” to conduct live fire. Again, since perfecting a mortarman’s technique in conducting hip shoots is nowhere close to the CAX force’s stated objectives, we don’t take advantage of the opportunity to fix a potential problem. The time is available, the people are in place, the scenario is written, and the ammunition is paid for and allocated, so why not get something real out of it instead of learning the wrong lesson to fall back on later when under the friction of war? Let’s use our time, money, and efforts better than we are doing currently by focusing on a higher percentage of personnel during CAX. To the CAX force, it’s the unit’s responsibility to be prepared to conduct hip shoots properly prior to arriving. Unfortunately, Twentynine Palms is one of the few places where the proper way can be learned and executed, so time isn’t available beforehand for units not stationed in the Mojave Desert. Should the CAX take proper mortar gunnery as a stated task and evaluate it accordingly, units would in turn focus their attention on it. Although I argue with myself (and sometimes win the argument), I often convince myself that learning the wrong lessons through live fire is as bad as not firing at all. During stress, individuals, and even groups, will fall back upon the “way they did it during live fire” and never remember the caveat of “you wouldn’t do it this way during war, but for safety’s sake,” etc., etc.! Just like in baseball or any other sport, Marines will play the way they practice. Their instinctive reflexive action will revert to the physical manner in which they practiced. For this reason, modifying the technique in order to play “live” may be more detrimental than not firing at all—if it is done completely wrong.
The actions of a mortar section at the CAX are pretty set. While driving along in trace of the battalion lead elements, a call for fire mission comes over the radio. The mortar section peels off to a flank so as not to fire over the heads of friendly forces. While the guns dismount, the fire direction center (FDC) is setting up the plotting board, plotting the grid of the target, identifying the gun section’s own location, developing a grid azimuth of fire from the gun line to the target, converting the grid azimuth to magnetic, and sending the azimuth down the gun line. One of two things happens at this point. Either the section leader is setting up the aiming circle to get a precise lay of the gun line, or he is following proper hip shoot techniques and standing behind the base gun with a compass, laying the gun by compass. The difference in technique is about 3 minutes. The aiming circle technique will take up to 4 minutes and 40 seconds to be FireCap, while the compass technique can have a round out in less than 1 minute. The aiming circle technique will usually result in the round landing closer to the target than when using the compass, but it’s like the old adage, “it’s better to have a good solution that will work right now, rather than the perfect solution sometime tomorrow.”
The technique for the proper hip shoot is to have one Marine with one compass lay all four guns onto the same firing azimuth. This Marine is usually the section leader with a declinated compass. I prefer to use a normal lensatic compass, since close is good enough when dealing with mortars. I’m attempting to get the round out quickly, in the vicinity of the target, so that the FO can adjust it rapidly. A side benefit to this rapid shooting is that the enemy now knows I’m coming after him, so I can add some anxiety to his day. The section leader starts with the base gun, laying him on an azimuth determined by either plotting the target on the map and determining an azimuth from the section’s position to the target, or by setting up the plotting board. The map is usually faster since it doesn’t have to be recreated after every move. There is no way to build the data on the plotting board in advance when traveling unknown distances between firing. Once the section leader lays the base gun, the range is determined by using the map again, the range is translated into elevation data using the target firing tables, and the round is fired. While the round is being fired, the section leader using the same compass lays the remaining guns. The base gun does not reciprocally lay them. This would take too much time. Now the remaining guns match data to the base gun and await the fire for effect. The sheaf upon impact will be ugly, but it is high explosive and entitled to being as ugly as it wants to be. The FO can search and traverse an ugly sheaf over the enemy, and the enemy won’t care a bit that the sheaf wasn’t evenly spread and pretty.
This sounds all very simple, and it is, but we talk ourselves out of doing this because we are afraid the Coyotes will place us in a check fire if we are too far off the target with the first round. In the Infantry Officer Course (IOC), this procedure is taught to get a round downrange immediately—even if it’s off by a click or two—so the adjustments can be made. It has proven to be faster. I think IOC calls it a registration shot, but I’m not too clear on that anymore. I do know it’s less used than the precision of the aiming circle. Even those who are extremely fast with laying the aiming circle can’t beat the simplicity of mounting by compass and shooting.
The process of using the aiming circle is as follows. The section, while traveling, receives a call for fire. The section stops and everyone dismounts. The section leader moves to the flank and sets up the aiming circle. He is allowed 2 minutes to do this. Meanwhile, the guns are being mounted in the direction of fire. The FDC is determining their own location and building the data on the plotting board. Since the plotting board only allows a limited amount of terrain to be recorded on it, it cannot be set up in advance. Once the section’s current position is determined and the plotting board created, the FDC plots the grid to the target on the plotting board using two men with two different plotting boards. These two men must be within a certain reading to be accurate, and will often replot if they are more than 10 mils off each other’s data (although some have learned to use only one plotting board during hip shoots to be more responsive). After the firing azimuth is determined, it is sent to the section leader who finishes laying the aiming circle. (He can’t finish laying the circle until he has this information.) Then he commands the section to refer sights to his instrument and to lay the guns parallel with each other on the firing azimuth. He has 90 seconds to perform this task. Next, the guns are told to refer sights to lay aiming posts and to place out aiming posts. The gun crews have 70 seconds to place out aiming posts. Finally, they are ordered to fire the section. The combination of aiming circle, reciprocal lay, aiming stakes, and firing have no chance but to be slower. Upon impact the sheaf will look much prettier than with the “lay by compass method,” but by this time the casualty count of friendlies could be much higher, or the enemy could have left the area entirely.
continued.....
by CWO3 Jeffrey L. Eby
Mortar gunnery should be a stated task at CAX in order that units spend time ensuring mortar teams are properly trained.
Mortars are outstanding weapons. Yet mortarmen, like most Marines, attempt to attain perfection at the expense of responsiveness. In an effort to “hit” the target, an emphasis is placed on first round precision vice sufficient suppression in a rapid timeframe. The rotation of forces to the Combined Arms Exercise (CAX) at Twentynine Palms may be indirectly part of the problem. We must refocus on what we want from our mortars and ensure our training goals are established to achieve this end.
The reason I blame the CAX for the development of precise, unresponsive mortars is due to the expectation that the first round fired on a hip shoot be “relatively close” to the objective. What is relatively close? That is at the whim of the senior evaluator. In the Mojave Desert a few miles is relatively close by one point of view. To the friendly force subjected to an errant round, 1,000 meters is relatively close. The problem is to identify what relatively close is in the mind of the enemy receiving our fires and train accordingly. I would suppose the enemy is much like us, and an exploding round within 1,000 meters is relatively close. This expectation, coupled with no sense of urgency to fire the first round, drives units to forgo speed. Since the skills of the mortarmen are not a stated goal of the CAX force, no emphasis is placed on meeting minimum time lines to be fire capable (FireCap) after mounting the guns, nor will a delay be taken to teach or recock the attack should the mortars take too long. The idea to be “close enough to be seen and adjusted by the forward observer (FO)” is not an issue, but it should be. The mortarmen appear to be attempting to develop a reputation for being sniper mortars. One shot, one kill was not the intent of mortar gunnery. The only way to alleviate this potential problem is to impose a time limit on hip shoots. This can be done safely with supervision and allows muscle memory to develop for the “right way” to do responsive hip shoots. Failure to meet the time limit forces the unit to recock and attempt the attack again and again and again.
Since the CAX is one of the few areas where units have the room to do a movement to contact hip shoot, the experience learned from this exercise will eventually override all other instruction and become “the way” to conduct live fire. Again, since perfecting a mortarman’s technique in conducting hip shoots is nowhere close to the CAX force’s stated objectives, we don’t take advantage of the opportunity to fix a potential problem. The time is available, the people are in place, the scenario is written, and the ammunition is paid for and allocated, so why not get something real out of it instead of learning the wrong lesson to fall back on later when under the friction of war? Let’s use our time, money, and efforts better than we are doing currently by focusing on a higher percentage of personnel during CAX. To the CAX force, it’s the unit’s responsibility to be prepared to conduct hip shoots properly prior to arriving. Unfortunately, Twentynine Palms is one of the few places where the proper way can be learned and executed, so time isn’t available beforehand for units not stationed in the Mojave Desert. Should the CAX take proper mortar gunnery as a stated task and evaluate it accordingly, units would in turn focus their attention on it. Although I argue with myself (and sometimes win the argument), I often convince myself that learning the wrong lessons through live fire is as bad as not firing at all. During stress, individuals, and even groups, will fall back upon the “way they did it during live fire” and never remember the caveat of “you wouldn’t do it this way during war, but for safety’s sake,” etc., etc.! Just like in baseball or any other sport, Marines will play the way they practice. Their instinctive reflexive action will revert to the physical manner in which they practiced. For this reason, modifying the technique in order to play “live” may be more detrimental than not firing at all—if it is done completely wrong.
The actions of a mortar section at the CAX are pretty set. While driving along in trace of the battalion lead elements, a call for fire mission comes over the radio. The mortar section peels off to a flank so as not to fire over the heads of friendly forces. While the guns dismount, the fire direction center (FDC) is setting up the plotting board, plotting the grid of the target, identifying the gun section’s own location, developing a grid azimuth of fire from the gun line to the target, converting the grid azimuth to magnetic, and sending the azimuth down the gun line. One of two things happens at this point. Either the section leader is setting up the aiming circle to get a precise lay of the gun line, or he is following proper hip shoot techniques and standing behind the base gun with a compass, laying the gun by compass. The difference in technique is about 3 minutes. The aiming circle technique will take up to 4 minutes and 40 seconds to be FireCap, while the compass technique can have a round out in less than 1 minute. The aiming circle technique will usually result in the round landing closer to the target than when using the compass, but it’s like the old adage, “it’s better to have a good solution that will work right now, rather than the perfect solution sometime tomorrow.”
The technique for the proper hip shoot is to have one Marine with one compass lay all four guns onto the same firing azimuth. This Marine is usually the section leader with a declinated compass. I prefer to use a normal lensatic compass, since close is good enough when dealing with mortars. I’m attempting to get the round out quickly, in the vicinity of the target, so that the FO can adjust it rapidly. A side benefit to this rapid shooting is that the enemy now knows I’m coming after him, so I can add some anxiety to his day. The section leader starts with the base gun, laying him on an azimuth determined by either plotting the target on the map and determining an azimuth from the section’s position to the target, or by setting up the plotting board. The map is usually faster since it doesn’t have to be recreated after every move. There is no way to build the data on the plotting board in advance when traveling unknown distances between firing. Once the section leader lays the base gun, the range is determined by using the map again, the range is translated into elevation data using the target firing tables, and the round is fired. While the round is being fired, the section leader using the same compass lays the remaining guns. The base gun does not reciprocally lay them. This would take too much time. Now the remaining guns match data to the base gun and await the fire for effect. The sheaf upon impact will be ugly, but it is high explosive and entitled to being as ugly as it wants to be. The FO can search and traverse an ugly sheaf over the enemy, and the enemy won’t care a bit that the sheaf wasn’t evenly spread and pretty.
This sounds all very simple, and it is, but we talk ourselves out of doing this because we are afraid the Coyotes will place us in a check fire if we are too far off the target with the first round. In the Infantry Officer Course (IOC), this procedure is taught to get a round downrange immediately—even if it’s off by a click or two—so the adjustments can be made. It has proven to be faster. I think IOC calls it a registration shot, but I’m not too clear on that anymore. I do know it’s less used than the precision of the aiming circle. Even those who are extremely fast with laying the aiming circle can’t beat the simplicity of mounting by compass and shooting.
The process of using the aiming circle is as follows. The section, while traveling, receives a call for fire. The section stops and everyone dismounts. The section leader moves to the flank and sets up the aiming circle. He is allowed 2 minutes to do this. Meanwhile, the guns are being mounted in the direction of fire. The FDC is determining their own location and building the data on the plotting board. Since the plotting board only allows a limited amount of terrain to be recorded on it, it cannot be set up in advance. Once the section’s current position is determined and the plotting board created, the FDC plots the grid to the target on the plotting board using two men with two different plotting boards. These two men must be within a certain reading to be accurate, and will often replot if they are more than 10 mils off each other’s data (although some have learned to use only one plotting board during hip shoots to be more responsive). After the firing azimuth is determined, it is sent to the section leader who finishes laying the aiming circle. (He can’t finish laying the circle until he has this information.) Then he commands the section to refer sights to his instrument and to lay the guns parallel with each other on the firing azimuth. He has 90 seconds to perform this task. Next, the guns are told to refer sights to lay aiming posts and to place out aiming posts. The gun crews have 70 seconds to place out aiming posts. Finally, they are ordered to fire the section. The combination of aiming circle, reciprocal lay, aiming stakes, and firing have no chance but to be slower. Upon impact the sheaf will look much prettier than with the “lay by compass method,” but by this time the casualty count of friendlies could be much higher, or the enemy could have left the area entirely.
continued.....