Hi Everyone,

Having spent some time reading through this forum I must say I am impressed by the general politeness and consideration of forum members - definitely up on some forums I have frequented.

I am currently writing a book on battle formations in the ancient world, with emphasis on Fertile Crescent armies, Greece, Macedonia and Rome. The first part of the book looks at formations in general and part of that looks at skirmisher formations: javelin, bow and sling.

The manuals make skirmisher formations half as deep as heavy infantry - 8 men per file as opposed to the ideal 16 men for heavy foot. This seems to correspond more or less to reality leading me to wonder why this was the case.

My proposed answer follows these lines: shooting in too much depth did not help skirmishers as they were designed to shoot a target moving towards them which they would eventually have to evade. Massed fire (they all shoot together) works only at maximum range as that is the only range an archer/slinger could be counted to maintain consistently whilst shooting blind. It seems counterintuitive but it is in fact much easier to shoot to a fixed distance at extreme range than at a much shorter range. At extreme range, a variation in the elevation of a bow or angle of release of a sling does not translate into much variation of distance the missile will cover (a look at shooting parabolas will clarify this), but at shorter ranges a slight variation in angle translates into a significant variation in distance. An advancing enemy line was broad but not deep: aiming wasn't important but accurately gauging the range of one's missile was.

Hence archers/slingers deployed in depth could shoot to maximum range only when they were shooting blind over the heads of their comrades. Once the enemy had advanced within that max range window the shooters would have to be able to sight them. This then limited fire to the front two ranks only, the second rank shooting between the men of the front rank. This being the case it was essential to rotate the front ranks: they shoot, countermarch to the rear, are replaced by the ranks behind them who shoot, etc. By the time the original shooters have reached the front they have reloaded and are ready to shoot again.

In this scenario it is not necessary to have a deep line, just one deep enough to allow shooters enough time to reload before reaching the front again. Presuming that a slinger line is deployed in open formation, 4 men per file can shoot at any one time: the front 2 men move into the file gap to the right of their file; the 3rd and 4th men move up; all shoot; the 4 men countermarch down the file gap to the rear and are replaced by the next 4 men in the file, and so on. This makes sense of Vegetius' injunction that slingers must swing only once overhead before loosing their bullet - they need to shoot as quickly as possible to allow the chaps behind them to shoot next.

The manuals assign 8 men to each skirmisher file. That's in intermediate order. In open order (necessary to allow the skirmishers space to countermarch to the rear) there will be 16 men per file. That means that 1/4 of the file is shooting at any given moment. That gives each man the time of three 'shoots' to countermarch to the rear, reload his sling, and ready himself for the next shot. Sounds about right.

Comments?

where did you get that info? i would like to do some reading.

i like the rotation of front line that's how i imagine it.

but how do they reload and carry the ammo?

some ideas are :
1) they carry their ammo during the battle and either throw w/ low power (unlikely) or lay the ammo bag(?) down and throw .
2) they carry the max amount of stones that doesn't inhibit slinging 5-20 stones (?) depending on mass.Plus they have reloaders on the rear lines whose job is to carry a heavier load of stones where slingers can fill their small packs and return to the front.

another tactic would be to have javelins in front of heavy infantry and sling at will while the enemy advances, when in javelin range throw the javelins and retreat to the sides or through the ranks of heavy infantry. heavy infantry advances , skirmishers no longer having javelins they take a good position and sling to the enemy heavy infantry which is now in pitched battle.

i think alexander the great used skirmishers mingled with cavarly.

Sarosh wrote on Jun 5^th, 2018 at 11:01am:

where did you get that info? i would like to do some reading. i like the rotation of front line that's how i imagine it. but how do they reload and carry the ammo? some ideas are : 1) they carry their ammo during the battle and either throw w/ low power (unlikely) or lay the ammo bag(?) down and throw . 2) they carry the max amount of stones that doesn't inhibit slinging 5-20 stones (?) depending on mass.Plus they have reloaders on the rear lines whose job is to carry a heavier load of stones where slingers can fill their small packs and return to the front. another tactic would be to have javelins in front of heavy infantry and sling at will while the enemy advances, when in javelin range throw the javelins and retreat to the sides or through the ranks of heavy infantry. heavy infantry advances , skirmishers no longer having javelins they take a good position and sling to the enemy heavy infantry which is now in pitched battle. i think alexander the great used skirmishers mingled with cavarly.

I've based most of this on the manuals (Asklepiodotus, Aelian and Arrian) plus Polybius and Vegetius. Slingers AFAIK could carry their ammo in their cloaks or in a pouch, possibly adding to their store from missiles at the back of the line from time to time. So yes, reloaders do make sense. If an infantry line is advancing toward them and they commence firing at 200m in a massed volley, then shoot from the front ranks after that they will need a lot of bullets. Presuming the enemy advance at 2km/h whilst under fire, the slingers will have about 6 minutes shooting time before the enemy reach them. If the two front ranks shoot every 3 seconds then every slinger will use up 120 bullets. If a bullet weight around 250g he is carting 30kg around with him - not likely.

I had forgotten Balearic slingers having 3 slings making them capable of 3 massed volleys.

But how much on the money is the extreme-range-most-accurate-range hypothesis for experienced slingers on this forum?

You have some great intuitions JS, and that’s a really great summary. Please keep us posted on the book!

As far as your 6 minute estimate, that’s only true if the enemy doesn’t have ranged weapons also, so it’s unlikely they could hurl 120 glandes before needing to retreat from spears and arrows.

As far as questions of “typical “ range and accuracy... good luck!  This forum has been debating those two topics incessantly for 15 years ;D

I do completely agree with your counterintuitive assessment that it’s possible to be more accurate at extreme ranges. That’s a rather brilliant insight. As long as all the slingers are sufficiently strong, extra power is lost in nonlinear wind resistance and everyone’s range is about the same for a given size and shape of glande... yet another thing I need to experiment with when Roboslinger is up and running.  Hopefully some day we can back up claims like this with hard data!

NooneOfConsequence wrote on Jun 5^th, 2018 at 8:24pm:

I do completely agree with your counterintuitive assessment that it’s possible to be more accurate at extreme ranges. That’s a rather brilliant insight. As long as all the slingers are sufficiently strong, extra power is lost in nonlinear wind resistance and everyone’s range is about the same for a given size and shape of glande... yet another thing I need to experiment with when Roboslinger is up and running.  Hopefully some day we can back up claims like this with hard data!

I came across this arrow trajectory calculator. I used it to set a bow at a maximum range of about 230 yards: speed of arrow 180fps, mass of arrow 400g, arrow drag coefficient 1.95, angle 42 degrees (optimum for max range). Setting the resultant arrow trajectory as a baseline curve I then started playing around with elevations above and below 42 degrees. Distance arrow covered: 230 yards

Get this: at 37 degrees elevation the arrow travelled 226 yards. At 47 degrees the arrow travelled 228.5 yards. That's a range difference of 4 yards for an elevation difference of 10 degrees. This difference in elevation:

https://i.imgur.com/VP8irKy.png

Would have made pinpoint extreme range shooting a piece of cake.

I think your formation is moving on the very slow side.  Standard marching cadence is one hundred to one hundred and twenty paces per minute, length of pace varies from country to country but the rate has remained pretty steady over the centuries.  That's the beat for most military music, the beat set the pace count so the formation stayed together.

So, if one side starts from 300 meters out, or even 400, which is outside of most archery ranges, you can expect the formation to cover that distance in about 4 minutes at a marching pace.  Half that if the force goes to double time, or a jogging run.  They aren't going to move slowly and let slingers, archers and javeliners get their shots off if they can help it.

And the slingers will be spending a certain amount of that time getting out of the way, they don't want to be trapped between the two shield lines.  And the defending line would not take a chance on opening their formation to let the slingers in when the enemy is charging towards them, so all your missile guys are going to running towards the flanks of the lines.

So, a pouch of 25-50g projectiles will be plenty for the lead up to the battle.  The resupply should be on the flanks of the main force. 

Skirmisher's duties were to keep the enemy's reconasiance forces back to keep the enemy from seeing exactly how your force was arranged and whether or not you had any nasty surprises waiting.  His skirmishers are trying to do the same to yours, too.  If you could inflict any damage to his main force, that was a bonus.

Bill Skinner wrote on Jun 6^th, 2018 at 5:36pm:

I think your formation is moving on the very slow side.  Standard marching cadence is one hundred to one hundred and twenty paces per minute, length of pace varies from country to country but the rate has remained pretty steady over the centuries.  That's the beat for most military music, the beat set the pace count so the formation stayed together. So, if one side starts from 300 meters out, or even 400, which is outside of most archery ranges, you can expect the formation to cover that distance in about 4 minutes at a marching pace.  Half that if the force goes to double time, or a jogging run.  They aren't going to move slowly and let slingers, archers and javeliners get their shots off if they can help it. And the slingers will be spending a certain amount of that time getting out of the way, they don't want to be trapped between the two shield lines.  And the defending line would not take a chance on opening their formation to let the slingers in when the enemy is charging towards them, so all your missile guys are going to running towards the flanks of the lines. So, a pouch of 25-50g projectiles will be plenty for the lead up to the battle.  The resupply should be on the flanks of the main force.  Skirmisher's duties were to keep the enemy's reconasiance forces back to keep the enemy from seeing exactly how your force was arranged and whether or not you had any nasty surprises waiting.  His skirmishers are trying to do the same to yours, too.  If you could inflict any damage to his main force, that was a bonus.

Fair enough. The only question is how fast an infantryman could move whilst covering himself with his shield against incoming projectiles. I'm not sure about a jog but a fast march is certainly feasible.

The heavies behind the skirmisher line would be in open order, with gaps between the files. It would be a question of timing the retirement of the skirmishers through the heavies then having heavies' files double to intermediate order (shields touching) and be ready for the arrival of the enemy foot.

It would be trickier for a Macedonian phalanx: the files would have to start in open order, double to intermediate order once the lights have passed through, then double again to close order and lower pikes ready to receive the enemy. That would take a little time.

weird I definitely posted here last week.
Right, I pretty much disagree on all your points (you'll find this isn't unusual when I'm explaining things to historians :-) )

Okay.
Lets start with what should be blindingly obvious, but is usually overlooked.
Slingers are NOT archers.

We have only one thing in common with archers - both 'fire' projectiles.
That's it, that is the ONLY thing we have in common.

To start with a slinger can carry a lot more ammunition and - more importantly - a number of slings suited for different purposes.
Archers tend to just have the one bow. Which limits them in both range and power.

Balearic slingers were known for carrying at least three slings of different lengths.

So in their case the maximum slinging range could be adjusted simply by changing to a shorter or longer sling. 
Such a change takes seconds.
The slings usually worn on the body.

Also as long as you have a spotter it is easy to hit a target you can't actually see (been there. done that). There would be no problem with experienced slingers walking their shots into an advancing army from behing the main army.

And even the in-experienced slingers could adjust range simply be changing to a longer or shorter sling and using the exact same throw style and power.

Slingers are much more versatile then archers - it's the main reason we persisted so long into the bow era.
Other reasons include the psychological impact of slinging on an enemy.
Sling bullets are traditionally small and light, but dense. You cannot see a sling bullet coming - but by god you can hear it !

Due a to a communications error, I have stood directly in line with an incoming lead glande, thrown by larry bray. landed about 6 feet directly in front of me. I think we were using lead fishing weights. Even as round a glande as that made a noise like a whole swarm of bees.
So you get the noise, then the significant impact, but unlike an arrow you never see the missile in flight.

Because ammo is light, whether using stones, lead or clay - a slinger can carry a significant volume and number of missiles.
50gm lead glandes.  20 to a kilo, 200 in an easy to carry 10kg bag.
If you were to sling at a conservative 5 shots a minute you could keep that up for 40 minutes.
And for max distance - and you need to start thinking 300 metres plus here (another difference to archers, slingers have a LOT more range).
You do need a windup.

Once you cut the distance down to the 200 metre mark you can, change slings and speed up to - again - an easy to maintain 10-12 shots a minute.
So 20 minutes per 10kg lead glandes.

At the 100 metre mark, you can again switch slings and fire at will (never name your son 'will' if he's going to be a soldier).

At the 100 metre mark you could use the alternate rank system (enfilade ?). A good slinger can throw 100 metres with a very flat trajectory. So at point blank range (100 metres or less) alternating ranks would work quite well.

But you need to stop thinking that slingers and archers are comparable. They are not. 

Slingers were invariably specialist mercenaries. It takes years to make a really good slinger.
A competent archer can be trained in a week or 2.
He has a point and shoot weapon that uses stored energy.

Slingers have nothing but muscle memory and experience. The argument that a good slinger is born not made, has merit
Without natural hand eye coordination - you will never be a good slinger.
But you could be an adequate archer.

I've seen people who have been slinging for years, who are lucky if the stone goes even in the vague direction they were aiming for (naming no names).

Another advantage slingers have over archers is the weather.
Slingers are not adversely effected by wet weather. Okay heavy rain will cut down your maximum distance. But wet slings work just as well as dry ones. Wet bowstrings - particular ones traditionally made from gut - do not work well in wet weather.    

Ammunition. Making and fletching a good arrow is a skilled business and not a short job.

Sling ammunition on the other hand can be picked up from the ground in the right terrain.
Or made from clay, rolled by hand and dried by a campfire.
Even casting lead glandes is a much much faster and easier process that making arrows and can be done by almost anyone with a little practice.

So while most slingers could easily make or find their own ammo - archers generally need skilled fletchers.

An advantage that archers have over slingers is the simple fact that they can see their ammo all the way to it's target.
A sling bullet tends to go out of sight at around the 100-150 metre mark.
So it is hard to gauge just where, beyond that range your missile is landing. Hence the need a for good spotters.

So while it's fairly easy to drop a missile on a distanr spot - if it's big enough, you can't actually see it land. Which is again where experience comes into the game.

And that's basically why sling troops died out. It just takes too long to train and acquire that experience.

So as far as the disposition and usage of sling troops goes. They can engage at ranges much further than archers.
Easily keep the enemy engaged right up to the point where spears become practical.
Fire faster and in more prolonged sessions than archers.
And have nore than one maximum range - depending on the length of sling they use.   
At short range, they can also switch to heavier ammo to do more damage.
They could also adjust range by using different size and weight missiles as well as different length slings.

In short, no matter where you put them slingers can engage the enemy at every point in the battle from over 300 metres down to hand to hand combat range.   

C_A  Good points.

I have one quibble, you can teach someone to shoot a bow in a week, yes, but it takes about a minimum of six months to work up to a decent power bow and about a year to work up to a war bow level. 

You are pushing with one arm and pulling with the other, the only thing that exercises your body like that is a bow.  And it takes time to build those muscles.  Even with regular practice.

One thing you didn't mention is that arrows are a weight forward, air resistance rear, that slows down a great deal the further the range.  That's why the English shot those extremely heavy arrows and the horse archers shot super light arrows with tiny fletchs, so they would still have enough velocity to penetrate at long range.

what arrows do you think ancient armies used?
on the web i can't find mass of arrows only quantity roughly...

Quote:

Quivers containing sixty arrows were strapped to the backs of the cavalrymen and to their horses. Mongol archers typically carried 2 to 3 bows (one heavier and intended for dismounted use, the other lighter and used from horseback) that were accompanied by multiple quivers and files for sharpening their arrowheads.

https://en.wikipedia.org/wiki/Mongol_military_tactics_and_organization#Mongol_bow
maybe mongols were too advanced for roman era archers :P 

@Curious Aardvark although arrows are harder to be made they might be lighter than the stones a slinger would use.
an archer can shoot his bow while having a quiver on him a slinger has to move around so the more he carries the worse he performs

@Curious Aardvark: many thanks for the long and informative post. This is just what I was looking for.

A couple of questions:

1. For a slinger range is about muscle memory and experience, i.e. the slinger acquires the feel for when to loose at different ranges by having shot many times at those different ranges. For ranges beyond 100 - 150 yards he needs a spotter to tell him his bullet has hit the mark or not. An experienced slinger then can shoot blind at many ranges or even any different range. My question: in terms of range how accurate could a slinger be when shooting blind like this? At a sling's extreme range less accuracy is required as the parabolic flight varies less with different angles of release. But I suspect at shorter ranges it will be more difficult since a slight difference of angle translates into a significant difference of range. Can a slinger in fact land a bullet within a few yards of 100 yards, 150 yards, 200 yards, 250 yards and 300 yards?

2. At shorter ranges where the trajectory is flattened, is it dangerous for a slinger to shoot over the heads of his colleagues in front of him if all are shooting at the same time? In other words is there risk his bullet will hit the whirling sling of the chaps in front?

That's one of the draw backs of slings, you have to have space to sling.  Using shorter slings with less wind up and throwing in unison can negate part of that.

Shorter slings usually mean less range, though.

You haven't mentioned staff slings yet.

Bill Skinner wrote on Jun 9^th, 2018 at 8:46pm:

That's one of the draw backs of slings, you have to have space to sling.  Using shorter slings with less wind up and throwing in unison can negate part of that. Shorter slings usually mean less range, though. You haven't mentioned staff slings yet.

Following Vegetius each slinger has about 2 yards depth and one yard width, which should be enough space to wield a good-sized sling. I passed over staff slings since they're not in the period of my book - Fertile Crescent armies to Roman Republic.

My (very uneducated) understanding of staff slings is that their weren't specific units of staff slingers and was more a weapon used during sieges and just handed out to anyone that was on the walls.

If you look at the lighter lead ammunition used by some armies of ancient times, to me it suggests that the purpose of such light ammunition was to use very short slings.

Just a few of the possible military advantages of such light ammo would be:

1. A denser formation.

2. Carrying more shots

3. Getting more shots off in a short period of time. (Shorter slings are considerably faster to throw. )

4. Focusing more on wounding the enemy rather than instantly killing which drains resources from the enemy to care for them. Such a tactic is also employed by modern militaries with their lower caliber weapons.

Whether or not it would be safer is a matter of debate. With very light ammo ,as was used at times, you could say the slings used were shorter and therefore less chance of hitting their neighbor. But they might have also simply opted for packing the formation closer together to get a denser shot pattern. In which case it might not have been any safer but still offered an advantage.

Distance with a short sling and light lead ammo should be looked into more. Total energy produced by a throw is not always the deciding factor on over all distance. A short sling that can accelerate quickly might throw a lighter ammo just as far or father than a longer sling.

For reference to this concept look into flight shooting with bows where at times a far heavier bow will not shoot an arrow as far as a much lighter one. This effect happens due to the extremely light nature of the ammunition used and the maximum acceleration possible for a given weapons design. This might also give insight into why, at times, very light lead glandes were employed.

the actual weight of the ammo is not an issue.
The density is far more important.

A 50gm lead glande when held feels heavier than it is because of the density and can easily be used in a distance sling.

But obviously it will fly further from a shorther sling than less dense ammunition.

I can get around 250 metres with a 32 inch sling and a stone. So should be able to get more distance with lead.

It's my standard multi-purpose sling ,length.
I have one a little shorter, around 27 inches that i use for target shooting.
Still get a fair distance with that.

i'm asking about mass per projectile because how much weight can a slinger carry while  running and/or slinging?

e.g. if he likes 250g stones/glandes he carries 20x0.250=5 kg
another one who likes 50g can carry 100x0.05kg=5kg
or same amount 20x0.05=1kg==> more ammo or more agile.

so maybe lighter ammo was prefered in order to do more effective skirmishing? :-/

Curious Aardvark wrote on Jun 11^th, 2018 at 8:17am:

the actual weight of the ammo is not an issue. The density is far more important. A 50gm lead glande when held feels heavier than it is because of the density and can easily be used in a distance sling. But obviously it will fly further from a shorther sling than less dense ammunition. I can get around 250 metres with a 32 inch sling and a stone. So should be able to get more distance with lead.

How heavy is the stone? By the way that's a great distance for any weight/sling length combo. My best to date is closer to 150 meters with concrete and I was thrilled to get that.

I think it's possible the dense lead lends itself to war not only because of the greater distance achieved but I would imagine the smaller profile penetrated into the enemy soldiers much further as well. All in all low mass lead ammo makes a lot of sense.

The story about smaller, lighter weapons wounding more and thus requiring more people to care for them is a modern day myth.

We and everybody else went to a lighter weapon and lighter ammo simply so the individual could carry more ammo.  It was an attempt to lighten the load carried by the individual.  The smaller stuff is actually more lethal than a lot of the older, more powerful stuff.

I think that the smaller ammo penetrated better and had a much better chance of incapacitating anyone it hit than we give it credit for.  If a guy is going to do something extremely physical like fight with a sword and shield, if he has a hole in him in an arm or leg from one of those smaller glandes, his chances of winning his fight decrease rather dramatically if his opponent is not wounded.

Bill Skinner wrote on Jun 11^th, 2018 at 12:16pm:

I think that the smaller ammo penetrated better and had a much better chance of incapacitating anyone it hit than we give it credit for.

Having done a small amount of research on the subject, the smaller intermediate cartridges do seem to perform better in penetration tests compared to rifle cartridges against kevlar vests (Excluding the usage of specifically AP ammunition).

This also bears itself out with PDW's, which often despite having very small cartridges are often capable of penetrating ballistics vests (Something which most pistols will fail against). Surface area/sectional density seems to be one of the important parts alongside having a high velocity in determining how effective firearms will perform versus armour.

Injury wise, high-velocity low-weight projectiles can be amazingly effective at causing tissue damage. Tests with 5.56 cartridges show that there is a high percentage of yawing or tumbling within several inches of penetration... and that is some scary stuff. This also bears itself with PDW rounds as well. At Fort Hood in 2009 there was a shoot out where the assailant used a five-seven pistol, and the effects caused by the cartridge are quite alarming (Especially when you consider that it was fired from a pistol). One soldier had her femur shattered by a single shot. After killing 13 people and injuring 32 others, the shooter still had 177 rounds left inside magazines held in his pockets.

That has always sounded a bit "urban legendish" to me. Good to get that cleared up.

I think over all the short sling and low ammo weight does make sense for the other reasons stated and of course probably for others we aren't aware of. The biggest factor being they chose to use it. Winners pass on tactics, losers tactics die with them.

A short sling and light ammo is better for short range and high rate of fire. Even if the light ammo does very little damage, if you mix a few heavy projectiles in too, the enemy will quickly learn to keep their heads down. Even if there isn’t a single casualty though, it affects their mobility and ability to respond. This is known as “cover fire”.

Short slings are also better for putting more slingers into less space which also ups the rate of fire per linear meter of battle lines... but this comes at the expense of range and potential damage per shot. If I were building a rank of slingers, I would put many short slings with light ammo up front and mix in a few with long slings and heavy ammo just behind them... but I’ve never commanded an army before so I’m curious if this was actually done historically.

I can certainly see slings being a highly useful psychological weapon. Even if you are so armoured a sling stone will do no penetrating damage the disorientation of being hit multiple times by potentially hundreds of projectiles, of having your shield get bashed about all over the place, of rocks bouncing off your friends helmets and into yours... It's not going to be fun to be under sustained fire whether you are actually injured or not.

Covering or surpressing fire doesn't work unless you are actually hitting people.

That's true with MG's and rifles, pretty sure it also applied to slings. 

You tend to ignore ineffective fires.  You do pay rather close attention to stuff that is hitting in amongst you.

Why couldn't a slinger be more of a stealth sniper rather than a pack of easy targets , I think that a high skilled slinger is best on his own not in a group

Mersa wrote on Jun 22^nd, 2018 at 4:35am:

Why couldn't a slinger be more of a stealth sniper rather than a pack of easy targets , I think that a high skilled slinger is best on his own not in a group

They aren’t easy targets if they out range everyone else on the field. I’m not sure why you express it as an either/or anyway, and I don’t know how you stealthily whirl your arms around your head, but a sniper serves a very different role on the battlefield from an organized rank of slingers.  If someone sneaks close enough to take a precision shot, they still have to egress. If it’s a one-shot kind of thing, then that seems like a waste of a skilled slinger as a battlefield resource.

Bill Skinner wrote on Jun 21^st, 2018 at 4:25pm:

Covering or surpressing fire doesn't work unless you are actually hitting people. That's true with MG's and rifles, pretty sure it also applied to slings.  You tend to ignore ineffective fires.  You do pay rather close attention to stuff that is hitting in amongst you.

Obviously the suppression effect is secondary to actually doing damage, regardless of the weapon we are talking about. It’s generally a bad policy to deploy ineffective weapons on the battlefield, so I’m not sure what your point is exactly.
If it’s not perceived as a legitimate threat, it has no suppressive effect. It’s possible to be an unseen threat or to be seen as a threat when you aren’t, but the best way to be perceived as a threat is to actually be one and then psychologically train your enemy to react defensively when they get the right cues. If you abuse that by trying to inflate the threat, they will adapt pretty fast.

Edit: I reread what I said and what you said, and I get it now. I was not suggesting that you use ammo so light that it doesn’t do damage. I was only saying that a mix of harassing fire and heavy shots would force the enemy to assume every shot could be deadly, but with a higher sustained rate of fire from mixing in lighter ammo, you could severely limit their mobility and ability to counter. Obviously the light stuff should still be a threat though. 

No wind up , Byzantine! Boom dead , move position , boom dead.

I think you play too many video games Mersa. If it was that easy, we’d see a lot more historical examples of that tactic.

You can get distance or accuracy, but if you tried sniping like that, you’d have to get close and you’d be overwhelmed.  A group of slingers can maintain sustained volleys which make it harder to rush them.

Na I think that unskilled and skilled slingers made up groups in armies, the best!! of the best!! would be assassins .

I guess that would really depend on the terrain.  You’d need good mobility and enough foliage to conceal your movements but not so dense that it keeps you from slinging.  You’d want rough terrain between you and your enemy so they can’t overwhelm you but you need to be able to reposition quickly. That’s a pretty specific set of circumstances that would be needed for your tactical approach, but I suppose it might work sometimes. 
As a kid, I used to play paintball with slingshots, and the tactics were completely different from how you play with paintball guns, because if you miss, your opponent could rush and hit you point blank before you reloaded. It made you choose your shots much more carefully... especially when the other side didn’t know your location. It was also a ton of fun :)