05-26-2011, 02:34 PM
From all appearances, the success of Tony's vision will largely hinge on increasing the number of rounds of small arms ammunition carried by the foot soldier while maintaining the per round effectiveness of the 7.62X51 NATO M80 ammunition type. The weapons include the carbine, the rifle to include designated marksman applications, light machine gun, and general purpose machine gun.
The drive is to improve the capabilities of dismounted versus motorized infantry. Ammunition weight, while important, is less of a constraint for weapons used by infantry when firing from vehicles.
BTW -- If the Rumsfeld acquisition doctrine still holds, we will need to describe the motivation in terms of filling a capability gap. The logic is that we can't afford to merely improve a component or system. We must first identify a capability that we don't have, need, and can't find a suitable work around.
In addition, I have the strong feeling that we are overlooking a significant strengthening of the motivation for what we're doing by not referencing any operational analyses that suggest a need for the ability to marry single round effectiveness of the 7.62X51 M80 round with the weight of 5.56 NATO ammunition.
I have also included the two requirements we've already reviewed.
PARTIAL DRAFT REQUIREMENTS:
Principal Requirement: Weight Reduction
Threshold:
[INDENT]Increase the number of rounds carried in magazines and belts by 25% for the same weight while using standard materials, e, g, brass and steel, as current 7.62X51 NATO ammunition while retaining at least the individual round effectiveness of the 7.62X51 NATO M80 round.[/INDENT]
Objective:
[INDENT]Increase the number of rounds carried in magazines and belts by 50% for the same weight while using standard materials, e, g, brass and steel, as current 7.62X51 NATO ammunition while retaining at least the individual round effectiveness of the 7.62X51 NATO M80 round.[/INDENT]
Rationale: Many user reports indicate a strong preference for the trajectory, lethality and barrier penetration of the 7.62X51 NATO M80 ammunition type, but suggest that the weight penalty has a significant impact on movement of dismounted infantry. The requirement for increased ammunition carry therefore includes the caveat that individual round effectiveness be maintained. Factors by which the effectiveness will be judged are spelled out in the following supplemental requirements.
Requirement 1: External Ballistics
Threshold:
[INDENT]Equal or better the vertex and wind drift of the 7.62X51 M80 at 300 and 1000 metres when using a 20-inch barrel.[/INDENT]
Objective:
[INDENT]Equal or better the vertex and wind drift of the 20-inch barrel 7.62X51 M80 at 300 and 1000 metres when using a 14-inch barrel.[/INDENT]
Rationale:
The trajectory of the 7.62 from standard-length barrels is a known and accepted performance level. Any new ammunition type will need to perform at least as well in the emerging new and shorter standard barrel lengths. Meeting or beating the 7.62 trajectory at either 300 or 1000 meters assures that the trajectory performance will be better than that of the 5.56 M855[/QUOTE]
Requirement 2: Barrier Penetration
Threshold: Steel plate defeat
[INDENT]Perforate a 3.5 mm (10 gauge) steel plate at a lower velocity than with a 150 gr .308 bullet when using an open tip match bullet in both calibers.[/INDENT]
Rationale: This threshold requirement establishes a relationship between bullet velocity, mass and diameter when standard bullets are used. The thickness specified is approximately the total thickness obtained when the three plates of the target defined in STANAG 4498 (NATO Medium Truck). The bullet selection is restricted to permit a near-standard comparison across calibers and to establish a minimum cartridge size for barrel length. The performance of the open tip match bullet on this target is presumed to match that of classic lead-filled full-metal jacketed bullets. The match bullets are specified to provide a wide variety of bullet weights while maintaining a standard bullet design class.
The comparison can be made by establishing the V50 velocity for each caliber and bullet being considered. V50 is the velocity at which approximately half of the bullets perforate and the other half don't.
Objective 1: Spaced Steel plate defeat
[INDENT]Equal or exceed the range at which the 7.62mm M80 round or the 5.56 M855 round from a 20" barrel can perforate the STANAG 4498 target at when the bullet impacts at 45 degrees from normal when using any bullet design with the mass and velocity established by meeting threshold with the standard bullet.[/INDENT]
Rationale: Meeting the threshold with the open tip match bullet as specified is the first step in a multistep design. Perforating the spaced plate at an angle is a significant increase in challenge. This added challenge may be met by upgrading the bullet design from open tip match to one that coincidentally more nearly satisfies the intent spelled out in the Hague and Geneva conventions relating to military small arms
Objective 2: Windshield defeat
[INDENT]Equal or exceed the range at which the 7.62mm M80 round or the 5.56 M855 round from a 20" barrel can defeat the target spelled out in "FBI Test 6" when using any bullet design with the mass and velocity established by meeting threshold with the standard bullet.[/INDENT]
Rationale: This objective completes the vehicular defeat requirements spelled out above. As in Objective 1, this added challenge may be met by upgrading the bullet design from open tip match to one that coincidentally more nearly satisfies the intent spelled out in the Hague and Geneva conventions relating to military small arms
Objective 3: SAPI Defeat
[INDENT]Defeat the NIJ Level III target with one fair hit when using any bullet design with the mass and velocity established by meeting threshold with the standard bullet.[/INDENT]
Rationale: Level III armor is designed to absorb as many as six fair hits of the M80 bullet at 2780 ft/sec prior to failure.
References:
A discussion of SAPI plates is here - http://en.wikipedia.org/wiki/Small_Arms_...ive_Insert
NIJ Standard-0101.05 is defined here: http://www.ncjrs.gov/pdffiles1/nij/223054.pdf and specifies protection level
FBI Test 6 spelled out here: http://greent.com/40Page/general/fbitest.htm[/QUOTE]
The drive is to improve the capabilities of dismounted versus motorized infantry. Ammunition weight, while important, is less of a constraint for weapons used by infantry when firing from vehicles.
BTW -- If the Rumsfeld acquisition doctrine still holds, we will need to describe the motivation in terms of filling a capability gap. The logic is that we can't afford to merely improve a component or system. We must first identify a capability that we don't have, need, and can't find a suitable work around.
In addition, I have the strong feeling that we are overlooking a significant strengthening of the motivation for what we're doing by not referencing any operational analyses that suggest a need for the ability to marry single round effectiveness of the 7.62X51 M80 round with the weight of 5.56 NATO ammunition.
I have also included the two requirements we've already reviewed.
PARTIAL DRAFT REQUIREMENTS:
Principal Requirement: Weight Reduction
Threshold:
[INDENT]Increase the number of rounds carried in magazines and belts by 25% for the same weight while using standard materials, e, g, brass and steel, as current 7.62X51 NATO ammunition while retaining at least the individual round effectiveness of the 7.62X51 NATO M80 round.[/INDENT]
Objective:
[INDENT]Increase the number of rounds carried in magazines and belts by 50% for the same weight while using standard materials, e, g, brass and steel, as current 7.62X51 NATO ammunition while retaining at least the individual round effectiveness of the 7.62X51 NATO M80 round.[/INDENT]
Rationale: Many user reports indicate a strong preference for the trajectory, lethality and barrier penetration of the 7.62X51 NATO M80 ammunition type, but suggest that the weight penalty has a significant impact on movement of dismounted infantry. The requirement for increased ammunition carry therefore includes the caveat that individual round effectiveness be maintained. Factors by which the effectiveness will be judged are spelled out in the following supplemental requirements.
Requirement 1: External Ballistics
Threshold:
[INDENT]Equal or better the vertex and wind drift of the 7.62X51 M80 at 300 and 1000 metres when using a 20-inch barrel.[/INDENT]
Objective:
[INDENT]Equal or better the vertex and wind drift of the 20-inch barrel 7.62X51 M80 at 300 and 1000 metres when using a 14-inch barrel.[/INDENT]
Rationale:
The trajectory of the 7.62 from standard-length barrels is a known and accepted performance level. Any new ammunition type will need to perform at least as well in the emerging new and shorter standard barrel lengths. Meeting or beating the 7.62 trajectory at either 300 or 1000 meters assures that the trajectory performance will be better than that of the 5.56 M855[/QUOTE]
Requirement 2: Barrier Penetration
Threshold: Steel plate defeat
[INDENT]Perforate a 3.5 mm (10 gauge) steel plate at a lower velocity than with a 150 gr .308 bullet when using an open tip match bullet in both calibers.[/INDENT]
Rationale: This threshold requirement establishes a relationship between bullet velocity, mass and diameter when standard bullets are used. The thickness specified is approximately the total thickness obtained when the three plates of the target defined in STANAG 4498 (NATO Medium Truck). The bullet selection is restricted to permit a near-standard comparison across calibers and to establish a minimum cartridge size for barrel length. The performance of the open tip match bullet on this target is presumed to match that of classic lead-filled full-metal jacketed bullets. The match bullets are specified to provide a wide variety of bullet weights while maintaining a standard bullet design class.
The comparison can be made by establishing the V50 velocity for each caliber and bullet being considered. V50 is the velocity at which approximately half of the bullets perforate and the other half don't.
Objective 1: Spaced Steel plate defeat
[INDENT]Equal or exceed the range at which the 7.62mm M80 round or the 5.56 M855 round from a 20" barrel can perforate the STANAG 4498 target at when the bullet impacts at 45 degrees from normal when using any bullet design with the mass and velocity established by meeting threshold with the standard bullet.[/INDENT]
Rationale: Meeting the threshold with the open tip match bullet as specified is the first step in a multistep design. Perforating the spaced plate at an angle is a significant increase in challenge. This added challenge may be met by upgrading the bullet design from open tip match to one that coincidentally more nearly satisfies the intent spelled out in the Hague and Geneva conventions relating to military small arms
Objective 2: Windshield defeat
[INDENT]Equal or exceed the range at which the 7.62mm M80 round or the 5.56 M855 round from a 20" barrel can defeat the target spelled out in "FBI Test 6" when using any bullet design with the mass and velocity established by meeting threshold with the standard bullet.[/INDENT]
Rationale: This objective completes the vehicular defeat requirements spelled out above. As in Objective 1, this added challenge may be met by upgrading the bullet design from open tip match to one that coincidentally more nearly satisfies the intent spelled out in the Hague and Geneva conventions relating to military small arms
Objective 3: SAPI Defeat
[INDENT]Defeat the NIJ Level III target with one fair hit when using any bullet design with the mass and velocity established by meeting threshold with the standard bullet.[/INDENT]
Rationale: Level III armor is designed to absorb as many as six fair hits of the M80 bullet at 2780 ft/sec prior to failure.
References:
A discussion of SAPI plates is here - http://en.wikipedia.org/wiki/Small_Arms_...ive_Insert
NIJ Standard-0101.05 is defined here: http://www.ncjrs.gov/pdffiles1/nij/223054.pdf and specifies protection level
FBI Test 6 spelled out here: http://greent.com/40Page/general/fbitest.htm[/QUOTE]