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Close Area Suppression Weapon (was Company Area Suppression Weapon)

  • Thread starter Thread starter Marc22
  • Start date Start date
MCG said:
And by that you mean that anything spin stabilized in an atmosphere naturally wants to invert itself and so we would expect the 40 mm grenade to return to earth facing backward & no longer stable?
Spin stablised is not a problem, so long as the spin is neither too much nor too little.  Too much spin, and it will "bottom out" when it hits earth, not enough and it will flop around. 
What I mean more is its mass.  It has less mass than other projectiles, and therefore less momentum (which helps stability and therefore accuracy).  Due to its lower mass, it is easily more affected by external forces: it goes back to Newton's laws.  A force at rest and all that.  So, it takes less wind to move a lighter object off its trajectory than one that has more mass.
 
Mortarman Rockpainter said:
Spin stablised is not a problem, so long as the spin is neither too much nor too little.  Too much spin, and it will "bottom out" when it hits earth, not enough and it will flop around. 
What I mean more is its mass.  It has less mass than other projectiles, and therefore less momentum (which helps stability and therefore accuracy).   Due to its lower mass, it is easily more affected by external forces: it goes back to Newton's laws.  A force at rest and all that.  So, it takes less wind to move a lighter object off its trajectory than one that has more mass.

Couldn't that be compensated for with some sort of drag on the back end of the projectile?
 
Reccesoldier said:
Couldn't that be compensated for with some sort of drag on the back end of the projectile?

Then to be used as Direct fire you need more propellant or a seperate ammo for direct and indirect, seems like a waste
 
Reccesoldier said:
Couldn't that be compensated for with some sort of drag on the back end of the projectile?
That would be fin stabalised.  It would not have a desire to invert itself in flight, but would still be affected by wind.

BulletMagnet said:
Then to be used as Direct fire you need more propellant or a seperate ammo for direct and indirect, seems like a waste
Many fin stabalised mortars already do direct & indirect, but (as you've pointed to, propellant is variable in such a system.
 
Right but the AGL is direct in that it is a point and shoot gernade...as in it's a gun you point and click, adding more drag to the end of a bullet (which is basicaly all the AGL runds are big Bullets that go BOOM) you'll need more propellant to compensate for the increased drag used to compensate for the light round used indirect.

So why bother just go with two rounds which is a strain on logistics but seeing as the 25MM has like 4 or so for combat it wouldn;t be that much for the system but it might be a bit in terms of the Company.
 
Increasing drag will not stop the effects of wind on a projectile.  If anything, that will increase it. 
 
MCG said:
Increasing drag will not stop the effects of wind on a projectile.  If anything, that will increase it. 

Nothing will stop the effects of wind, but even a very small amount of drag will keep the fuse end front as it should be.
 
MCG: you saved me: i was going to post exactly that.
Now, to avoid confusion, "direct fire" and "indirect fire" have nothing to do with trajectory.
Paraphrasing here, but "direct fire" is that fire in which the shooter sees the target area and aims and corrects fire by himself.  Indirect fire is that fire in which a third party sends information to the firer, including initial aiming point and any corrections.

As an example, a 60mm mortar crew sees an enemy platoon at 1200 metres.  They lay the sight on the target, "geusstimate" the range, and fire a round.  They see the impact, and they make corrections based on what they observe, until they hit the target.  That is direct fire.

Now imagine a GPMG crew dug in with the SF kit on a reverse slope.  It's night, and they have no night vision.  An OP some distance away sees bad guys "out there" and it's not near a DF.  So they send grid and stuff.  The MG Det comd plots the direction and distance, it's applied to the MG, and they fire.  They get corrections, until they are "on" the target.  That is indirect fire.
 
Reccesoldier said:
Nothing will stop the effects of wind, but even a very small amount of drag will keep the fuse end front as it should be.
The right amount of spin (not too much, not too little) will keep it nose-first. Rocket scientists and big brains figure out all that nonsense :D
 
Mortarman Rockpainter said:
The right amount of spin (not too much, not too little) will keep it nose-first. Rocket scientists and big brains figure out all that nonsense :D

So is there a rifled 40mm Coy area suppression weapon?

Scratch that.  Come to think of it, this isn't a fin stab/rifled problem it's purely a matter of mass.  In order to have an accurate indirect round a certain amount of mass is required to withstand the longer time of flight of an indirect trajectory.
 
Ok but back to the drag issue, if you have something causing more air friction slowing the round (weight. fins etc etc) you would need more force to move said round to compensate.

As for direct indirect fire I understood the difference but going with the previous theory of more drag it has a direct effect on the range of the round in both roles.

Now MRP is right in the end about how it all works just that to do it with the previous theory it wont work.

Reccesoldier, there is no 40mm CASW in current use within the Infantry.
 
BulletMagnet said:
Ok but back to the drag issue, if you have something causing more air friction slowing the round (weight. fins etc etc) you would need more force to move said round to compensate.

As for direct indirect fire I understood the difference but going with the previous theory of more drag it has a direct effect on the range of the round in both roles.

Now MRP is right in the end about how it all works just that to do it with the previous theory it wont work.

"Drag" can be created without significantly increasing weight.  If you take a ball and attach a straw to it and throw it the flight of the ball will eventually lead to the straw at the read end.  It's got more to do with aerodynamics than any significant "drag".

Reccesoldier, there is no 40mm CASW in current use within the Infantry.

I know, but, isn't the Mk19 rifled?  2200m seems like an awfully long way for a relatively light fused projectile to be shot without some spin to ensure a nice little boom at the end.
 
Drag is drag whatever you use to create it, weight etc you'll still in the end be slowing the projectiles movement through the air thus requiring more force to move the projectile equal distnace then the less drag round.,

As for rifled yes I believe though I do not know for sure that the MK19 is a rifled barrel, someone that has used one would have to say for sure.
 
Let us not forget that spin stabilisation also reduces overall range.  Some energy used to propel the projectile is lost in the projectile's spin.  That's why some tanks have smoothbores: higher projectile velocity.  (That's also why they have fin stabilisation: without it, they would not be stable)

 
http://www.globalsecurity.org/military/systems/ground/mk19.htm

MK19 40mm Machine Gun, MOD 3

The MK-19 (Mod 3) Automatic Grenade Launcher/Machine Gun is a selfpowered, air-cooled, belt-fed, blowback operated, crew-served weapon. The MK-19 replaces or augments selected M2 .50 caliber Machine Guns throughout the Army. It is also in use by the US Navy, Marines and Air Force. The MK-19 is mounted on HMMWV's, trucks and M88 Recovery Vehicles to deliver intense suppressive fire against enemy personnel and lightly armored vehicles or bunkers.

The MK19 Mod3 40mm Grenade Machine Gun was first developed by the Navy in the early 1960's. TACOM-ARDEC has since suggested modifications to this system which has enabled the Army to deploy the MK19 in the harsh environments encountered during world-wide operations and has therefore enhanced its performance. The MK19 firing rate is over 350 grenades per minute and it is effective to ranges of over 2200 meters. The system was deployed in Southwest Asia during Operation Desert Storm and devastated enemy infantry.

The MK19 40mm machine gun, MOD 3 is an air-cooled, disintegrating metallic link-belt fed, blowback operated, fully automatic weapon and is crew transportable over short distances with limited amounts of ammunition. It can fire a variety of 40mm grenades. The M430 HEDP 40mm grenade will pierce armor up to 2 inches thick, and will produce fragments to kill personnel within 5 meters and wound personnel within 15 meters of the point of impact. Associated components are: MK64 Cradle Mount, MOD 5; M3 Tripod Mount; and the AN/TVS-5 Night Vision Sight. The MK19 also mounts in the up-gunned weapons station of the LVTP7A1 model of the AAV and vehicle ring mounts.

Many antiarmor platoons have the capability to replace the TOW weapon system with either an MK19 (40-mm grenade machine gun) or the M2 (caliber .50 machine gun). This allows the platoon to provide fire support when there is no threat of enemy armor. Both of these weapon systems can be fired from the HMMWV, using the HMMWV interchangeable mount system (HIMS) and also ground mounted on a tripod.

The MKI9 is effective at 1,500 meters against point targets and out to 2,200 meters against area targets. The weapon has a sustained rate of fire of 40 rounds each minute and a rapid rate of fire of 60 rounds each minute. The weapon system (gun, tripod, and T&E) weighs about 120 pounds. A container of 48 rounds weighs 64 pounds. The weight of this system precludes manpacking for other than short distances. The AN/TVS-5 can be mounted on the weapon to provide effective night fires.

The standard round of ammunition is HEDP, which can defeat 50-mm of RHA or 16 inches of concrete. An HE round is also available for engaging troops in the open or other soft targets. Both rounds have a bursting radius of 15 meters and a flat trajectory out to 800 meters. The weapon can be employed in an indirect-fire role to engage targets from 800 meters out to the maximum effective range. The methods of controlling indirect fires is the same as the 60-mm mortar--direct lay, direct alignment, or an observer to provide corrections and the use of the T&E mechanism to apply these corrections to the gun.

In the offense, the MK19 can be employed similar to the 60-mm mortar in the indirect-fire role and similar to the TOW in the direct-fire role. The MK19 can be employed from an overmatch position to provide responsive suppressive fires if enemy contact is made. The weapon can also suppress/destroy enemy weapons and positions on the objective prior to the infantry assault. It may also support the isolation of the objective area by blocking likely avenues of approach with concentrated destructive fires. When employed from the M3 tripod with the T&E, the gun is very accurate for an area type weapon.

In the defense, the MKI9 can be effective in both the direct and indirect-fire roles. It can be assigned a priority target or an FPF just like a 60-mm mortar. The enemy will attempt to locate and destroy these weapons early in his attack. Unless the MK19s are employed from defilade/fire from prepared dug-in firing positions, they are very vulnerable. The mobility capability for the MK19 when mounted on the HMMWV must be balanced against the vehicle's vulnerability to detection, and destruction.

Although the MK 19 is a recent entry into the Army guns inventory, development began in 1963. The first version was a hand-cranked multiple grenade launcher called the MK 18. In 1966, the need for more fire power inspired the development of a self-powered 40-mm machine gun called the MK 19 MOD 0. This model was neither reliable enough nor safe enough for use as a military gun. Product improvements begun in 1971 resulted in the 1972 MOD 1, of which only six were produced. The MOD 1 performed effectively in Navy riverine patrol craft, and broader applications for the MK 19 were found. In 1973, the Navy developed the MOD 2, which featured improved reliability, safety and maintainability. In 1976, a complete redesign resulted in the MK 19 MOD 3, which the Army adopted in 1983. The Army uses the MK 19 within the tactical environment for defense, retrograde, patrolling, rear area security, MOUT, and special operations.

One of the ARNG critical readiness requirements is small arms and crew-served weapons modernization. With the advent of Army Transformation to Units of Action (UA's) the ARNG has currently documented shortfall of 3,377 MK-19's. Operational requirements resulting from the GWOT have resulted in extensive unit-to-unit transfers of MK-19's to deploying units. M2 .50 calber machine guns and operational barrels are also in short supply. As the primary supressive weapon for CS and CSS any shortage of these weapons is critical.

The RDD validates an ARNG requirement by 2005 for 9,159 MK-19's at a cost of $15.5k each. On hand are 5,782 MK-19's, the majority of which are deployed. Fielding to fill the previous ARNG requirement was completed in 2003 and the new increased requirement has not yet been programmed. The MK-19 UFR is 3,377 and may increase as ARNG modularity above UA level is documented. The only alternative weapon systems are the XM-307/312 Advanced Crew Served (Air-burst) Weapons which are still under development with no projected fielding date.

Funding the MK-19 will give National Guard Soldiers the same capability as Active Army Forces to deploy and operate with maximum effectiveness on all fronts of the Global war on Terror. It greatly contributes to their ability to rapidly defend themselves with high volume, suppressive fire in adverse conditions. Failure to fund the MK-19 will increase soldier risk and the costs of pre-deployment cross-leveling, which also degrades the ARNG's ability to train for and execute both its federal and state missions.


Manufacturer: Saco Defense Industries
Length: 43.1 inches (109.47 centimeters)
Weight:
Gun: 72.5 pounds (32.92 kilograms)
Cradle (MK64 Mod 5): 21.0 pounds (9.53 kilograms)
Tripod: 44.0 pounds (19.98 kilograms)
Total: 137.5 pounds (62.43 kilograms)
Muzzle velocity: 790 feet (240.69 meters) per second
Bore diameter: 40mm
Maximum range: 2200 meters
Maximum effective range: 1600 meters
Rates of fire:
Cyclic: 325-375 rounds per minute
Rapid: 60 rounds per minute
Sustained: 40 rounds per minute
Unit Replacement Cost: $13,758



 
MK47 MOD 0                                                      MK19 MOD 3
Caliber 40mm                                                    40mm
Gun weight 39.6 pounds (18 kg)                          77 pounds (35 kg)
Length 37 inches (940mm)                                  43.11 inches (1,095mm)
Length (Barrel detached) 24.02 inches (610mm)    N/A
Width 10.04 inches (255mm)                              13.39 inches (340mm)
Height 8.07 inches (205mm)                                8.19 inches (208mm)
Total charge pull 55 pounds (25 kg)                    99 pounds (45 kg)
% Mass recoiling 55%                                        22%
Maintenance Round counter                                N/A
 
Well - I've seen a US ODA attempt to use a Mk47 in a mortar like method and they gave up and got out their high speed mortar range was ~700m.
 They had the wizbang sight too FYI...


 
BulletMagnet said:
Drag is drag whatever you use to create, it weight etc you'll still in the end be slowing the projectiles movement through the air thus requiring more force to move the projectile equal distnace then the less drag round.
Mass is an object's resistance to acceleration.  Weight is the force of gravity acting on a mass; it is not drag (nor does weight create drag).  Drag is a result of object size, shape & surface, and of air turbulence & speed (relative to the projectile).  Air resistance (drag parallel to the direction of flight) can be described in four components which affect projectiles: forebody drag, base drag, skin friction, and excrescence drag (fins & wings).  But, most of the discussions on atmospheric forces thus far have focused on moving the projectile off the target.

The 40 mm projectile, having less mass than a 60 mm mortar projectile, will be more affected by an equal lateral force.  However, being smaller and without a tail, the 40 mm projectile will likely experience much less lateral force in the same wind as a 60 mm projectile.  I6 and a few others hear may have some experience (actual observations of both weapons firing under the same conditions) to make an educated guess.  Outside of those few, the best any of us can do while sitting in front of our computers,  is make wild guesses as to which projectile would be affected more at an given lateral wind speed (unless someone happens to have CAD projectile models and CFD software).
 
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