Laser distance air-bursting bullets? What do you think?

[McG]

a. the projectile can not be very large, so the explosive charge and the splinter pattern both must be fairly limited. It seems to me that it would only be about half of that of the 40mm round.

-Force of a hand grenade: I would say no.  A grenade has 150 odd grams of HE, a typical 20-30mm projectile 5 to 20.  40mm grenades: 20 to 40.  You may be able to optimize the frag pattern as you know which way the projectile will be facing when it functions (unlike a hand grenade), but you can only do so much with 15 grams.

I wonder if the technical evaluations of the round used the phrase "force of a hand grenade" or if that was artistic licence from a confused reporter upon hearing "lethality of a hand grenade"?  All other things being equal, an air-bursting grenade will produce more leathal fragmentation than the same grenade laying or impacting on the ground.  It is, therefore, conceivable (though not certain) that this 25 mm round could match the lethality of traditional grenades (hand tossed or PIPD 40 mm types).

The M397A1 is a 40 mm grenade for the M203.  About half the volume of the projectile is a carrier that is designed to (on impact with the ground) launch a smaller grenade to 1.5 m hight where it will detonate.  As this bounding 40 mm grenade sacrifices HE volume to gain the benefits of an air-burst, I suspect it is probably a better munition against which to compare the 25 mm airburst round.


http://www.janes.com/articles/Janes-Ammunition-Handbook/M397A1-40-mm-LV-HE-air-burst-grenade-United-States.html

 

[AmmoTech90]

Apologies for the short reply, postIng from my iPod touch.

The reason for the reduced terminal effects I mention is the reduced ke from having less force behind the fragments due to less he pushing.  The fragments may be better distributed due to airburst but have much smaller effective range which is why you need so much more accuracy.
Carefully engineered frag may mitigate this somewhat but you can only do so much with less than 20 grams
Once you get below 80 joules you are producing nonlethal frag for the most part.  Also remember the small casing available so you get less fragments of a useful size

One other thing an airbursting munition functioning over your head is sending half it's frag in the air above you just like a hand grenade sends half it's frag into the ground

 

[a_majoor]

Playing the devil's advocate a bit here:

A 25mm automatic micro grenade launcher would be a useful section/platoon support weapon. It should be much smaller and more portable than the "C-16" (hence far more usable), allow the crew to carry far more ammunition and engage a broader range of targets. The argument that it needs to be much bigger and heavier is belied by Chinese and Russian 35 and 30mm AGL's which are the same size and weight as a C-6 GPMG; given that proof of principle a 25mm man portable support weapon seems quite plausible.

What isn't very acceptable is the cost of such a weapon. The electronic parts of the day/night laser rangefinder and ballistic computer should not be "that" expensive (digital cameras and consumer electronics like iPods or iPhones are proof of principle), so there is lots of room for the procurement agencies to pressure vendors to bring the prices down. OTOH electronic fuses in a round will be expensive (they need to be packaged in a very small space and survive the shock of firing, not to mention the ability to receive data from the ballistic computer in the barrel), so this capability needs to be thought out very carefully. If the weapon's capabilities are entirely dependent on a programmable fuse, then perhaps this really is the wrong way to go.

 

[Old Sweat]

It seems to me that the ballistic computer and fuze setter could programme the round before it is chambered or fired. It is not really like firing a Sten or SMG, but the principle might be the same. In any case, recoil will be a problem for a shoulder fired weapon. Much of the weight of the weapon must surely be designed into it to absorb much of the backwards forces, or at least to transfer them to the firer.

My hangup is still the potential lethality of the round, especially as most of the fragments will be directed away from the area ahead/below of the point of burst.

 

[McG]

My hangup is still the potential lethality of the round, especially as most of the fragments will be directed away from the area ahead/below of the point of burst.

? The projectile already has a lot of KE (both linear and rotational) when it detonates and this is does not disappear - it is transferred to all the frag.  All this KE will infact give greater velocity to frag going forward in the direction of flight and in all directions perpendicular to that.  There will be reduced lethal & casualty distances to the rear of the projectile, but when firing over an obstacle the target will already be at least within 1 m of the programmed blast.

... and if a target is not behind an obstacle, then don't add the extra metre when shooting.

 

[NavyShooter]

Suppose there's more to the sight than "meets the eye" so to speak.

Since it's a small projo, with a small HE load, the placement is, obviously, important. 

Suppose the sight has an integrated digital camera.  When it lases for range, it also snaps a "photo" of the sight picture.

The soldier then dials in his delay for the fuse, and lines up on his target.

He squeezes his trigger, but the weapon won't actually fire until the sight picture matches that of what was lased for range.  I don't think it's an overly difficult piece of tech to include.  There's lots of electrically initiated weapons (think the CIWS on ships.)

Thoughts?

It's probably a pretty complex piece of kit in that optic anyhow, what's one more whiz-bang thing to add?

NS

 

[Old Sweat]

? The projectile already has a lot of KE (both linear and rotational) when it detonates and this is does not disappear - it is transferred to all the frag.  All this KE will infact give greater velocity to frag going forward in the direction of flight and in all directions perpendicular to that.  There will be reduced lethal & casualty distances to the rear of the projectile, but when firing over an obstacle the target will already be at least within 1 m of the programmed blast.

... and if a target is not behind an obstacle, then don't add the extra metre when shooting.

I understand all that. I also understand that the majority of the fragments are going to fly away upwards and forwards, just as is the case with any air burst projectile. The remainder will be quite lethal, but in a limited area. We are talking, after all, about a projectile roughly 50% larger than a 12 gauge shotgun deer slug. If the shooter is on the target, great. If not, it doesn't matter if it is a 25mm or a 155 mm, although the margin of error is much larger in the latter case.

It may be that the sighting system will compensate for my "litttle bang" theory. If so, I apologize in advance. Let's wait and see.

 

[vonGarvin]

Suppose there's more to the sight than "meets the eye" so to speak.

Since it's a small projo, with a small HE load, the placement is, obviously, important. 

Suppose the sight has an integrated digital camera.  When it lases for range, it also snaps a "photo" of the sight picture.

The soldier then dials in his delay for the fuse, and lines up on his target.

He squeezes his trigger, but the weapon won't actually fire until the sight picture matches that of what was lased for range.  I don't think it's an overly difficult piece of tech to include.  There's lots of electrically initiated weapons (think the CIWS on ships.)

Thoughts?

It's probably a pretty complex piece of kit in that optic anyhow, what's one more whiz-bang thing to add?

NS

We *could* do all that, or we could train our people to shoot effectively, so we can manoeuvre on the enemy to put a bullet in his face from up close.

 

[GAP]

In the decades since I have actively served I have seen more and more whizbang technology come forward, some useful, some marginal, lots just too complicated and time consuming for the soldier in a TIC......if the technology fails, whats the fall back position?

good solid soldiering.

 

[George Wallace]

We *could* do all that, or we could train our people to shoot effectively, so we can manoeuvre on the enemy to put a bullet in his face from up close.

Up close and personal?  I don't know if the new army is up for that.    >

 

[NavyShooter]

Sorry,

I didn't mean to suggest that we should go that way....I'm just wondering if it's a built-in doohickey that they're not chatting about to improve terminal potential.

The person carrying the tool should be able to use it effectively.

NS

 

[a_majoor]

The operation of the sight is actually far simpler than digital cameras and superimposed images. Sights of this sort have a mirror with the sight graticule engraved on it. You aim and lase the target, the ballistic computer calculates the range to the target and the required angle of elevation; the mirror is tilted by the required amount and the sight picture you see now has the graticule in the new position. The shooter then relays the weapon so the graticule is centered upon the target again, and fires.

For the XM-25 and similar weapons, a signal is sent to the electronic fuse at the same time, programing the round to detonate at distance "x". Should the shooter not relay the weapon after the graticule has changed, the round will still detonate after the required time has passed; a loud "bang" will take place somewhere; just not where the shooter expects.

Just to go back to the SPIW for a moment, there is a true case of overcomplicating the problem. As I understand it, the initial idea was to use something like a shotgun to fire flechettes, in the expectation the flechettes would have the velocity and penetrating power to take out a troop at battle range even with 1960 era protection (a steel helmet). Since the weapon had a large bore, deer slugs and mini grenades were also contemplated as part of the battle load so soldiers could engage a wide range of targets. (The developed AA-12 of today is probably what was intended back then). Of course, a faster flechette is even better, so loading something the size of a finishing nail in a 5.56X45 cartridge case was the ideal solution to velocity(but added untold complications to the design of the weapon).

So we should take what Technoviking and others have said, and look for the simplest and easiest solution to the problem of suppressing the enemy. 

 

[NavyShooter]

So we should take what Technoviking and others have said, and look for the simplest and easiest solution to the problem of suppressing the enemy. 

Mortars....??



NS

 

[vonGarvin]

So we should take what Technoviking and others have said, and look for the simplest and easiest solution to the problem of suppressing the enemy.

I would offer that we use the tools available, but by all means, embrace emerging technologies when they are mature enough to be fielded, remembering that technology alone cannot do any job for us (lest we stir up SKYNET) ;D

 

[GAP]

I would offer that we use the tools available, but by all means, embrace emerging technologies when they are mature enough to be fielded, remembering that technology alone cannot do any job for us (lest we stir up SKYNET) ;D

Oh.....you think it heard? 

 

[McG]

It may be that the sighting system will compensate for my "litttle bang" theory. If so, I apologize in advance. Let's wait and see.

Assuming that rotational and linear velocities of the projectile are exploited to compensate for the "little bang" in directions forward and to the sides of the projectile, the rearward compensation is achieved through the proximity of the detonation to the target.  Assuming the target (a human) is behind cover of negligible thickness (prefabricated armoured plates?), he will still be within 3/4 m or less away from the blast.  That is controlled by the projectile detonating 1 m beyond whatever is providing cover.  Any Section/fire team members to the targets rear or flanks  will be subject to the greater lethal radius of that frag that is able to exploit pre-detonation inertia to achieve greater velocity.

So we should ... look for the simplest and easiest solution to the problem of suppressing the enemy. 

It seems to me that this is not a suppressing tool.  It is a killing (destroy) tool.  Instead of suppressing the hidden gunman - the target is killed or made combat ineffective though injuries.  As was pointed out, we have tools that allow a patrol to suppress a few windows in a concrete building at 600 m.  There are not many options for reaching through that window and killing the guy straight below - immediately behind the protective wall.

A question was asked in another thread about breaking the current paradigm of Infantry fixing for Artillery to destroy.  Perhaps one way is to enable the Infantry to destroy under conditions where they are currently only able to fix.

 

[vonGarvin]

A question was asked in another thread about breaking the current paradigm of Infantry fixing for Artillery to destroy.  Perhaps one way is to enable the Infantry to destroy under conditions where they are currently only able to fix.

That's only a function of risk aversion.  We are able to destroy, but we refuse to (or so it seems). 

 

[a_majoor]

Although advertized as a "killing tool", in real life I suspect it will do a great job of suppressing the enemy. If the enemy soldier is inside the blast radius then he/she/it will be toast, and the fact there is a blast radius and a sight/fuse system to put the blast where the shooter wants it will increase the pK by a fair amount, but many factors will get in the way, including:

Soldiers who are frightened, tired or stressed. They might not aim properly (either to get the range, or properly relaying the weapon once the rangefinder has done its bit) so the round lands outside the lethal radius to the target.

The sight/fuse/round is defective, either through manufacturing fault or the day to day abuse of soldiers in the field (or even dust and moisture working its way inside the system). Never underestimate the clever private who wants to really see how the stuff inside works as well. ("Sergeant, I have these extra parts from when I looked at the inside of the sight....")

The enemy has a vote, and deploys new tactics or countermeasures to negate the effectiveness of the weapon.

Even with these factors in play, the fact there are blasts happening at or near where the enemy soldiers are will have the effect of suppressing them, or forcing them to leave their position to escape the effects of the fire. Most fire is suppressive in nature, since the shooters have very limited sight pictures or windows of opportunity to take aimed shots; the ability to keep their heads down while we carry out our COA is not something to be dismissed.

 

[Old Sweat]

Sincere thanks to MCG for addressing my concerns. Having said that, I still wonder if we are not talking about a "one trick pony" trying to haul a Clydesdale's load. Given the points Thucydides raises above, especially the point of aim, I still worry about the effectiveness of the round under combat conditions. A number of you have already pointed out here and in other threads about the lack of marskmanship holding, aiming and firing skills in our troops. If the firer is uinable to put the round in or near enough to the correct place to take the enemy out of the fight, what has been gained?

Having roiled the waters a bit, it is time for Sweatie to go back into the primordial swamp and dream of Fire Missions Division and coordinating DF tasks and dumping programmes and the rest of the gunner's world back when we worried about the Red Horde.

 

[NavyShooter]

NS any time you want to teach shooting, I volunteer to take lessons! I'm one of those who 'barely' passed the pwt 

How'd you find the lesson today?

I'm open for feedback....2.5 hours of talking/showing with not one round fired...but a lot covered...what's the one most important thing you took away?