Why were slings phased out of medieval armies in favor of bows?

Question

I was watching some videos on slings and was surprised by how long-ranged and powerful they could be. This test indicates its power could be similar to that of a 9mm bullet. According to Wikipedia, slings also had ranges comparable to or longer than that of bows:

A sling bullet lobbed in a high trajectory can achieve ranges in excess of 400 m (1,300 ft).[23] Modern authorities vary widely in their estimates of the effective range of ancient weapons. A bow and arrow could also have been used to produce a long range arcing trajectory, but ancient writers repeatedly stress the sling's advantage of range.

Slings were also much simpler to construct that bows, being effectively just a braided rope. Their ammunition was also plentiful (rocks) or easy to construct (lead bullets) in comparison to the complexity of an arrow.

However, they were largely phased out by the medieval era in favor of bows and crossbows. Why was this?

Answer 1

Phased out? Says who?

Slings were used in European armies until the 16th century...the Castilian king had 30,000 infantry slingers in 1386...The sling was last used in Europe for military purposes at the siege of Sancerre in 1572 by the Huguenots.

Here is a lovely illustration of slingers at the Siege of Damietta in 1219, operating alongside archers and against opposing crossbowmen.

So why weren't armies composed entirely of slingers, rather than archers?

The sling's primary weakness compared to the bow was the high skill level necessary to use it effectively. While a true expert with a sling could use it ambidextrously and with great accuracy, that level of ability required training from a young age. Harrison proposes that there were simply fewer trained slingers to go around:

Increased cultural diffusion and urbanization in the Middle Ages meant local cultural traditions, such as slinging, were weakened...By Medieval times, there were few pockets of experienced slingers left

Additionally, the way in which troops were deployed had evolved. Ancient slingers were great skirmishers but the space required for a slinger to operate made them a poor fit for the medieval battlefield of tightly packed bodies:

It would have been troublesome to pack multiple rows of slingers into a typical medieval assemblage, where each soldier would fire over the row in front of them. Even a slight misfire, launched in front but too low, could cause friendly casualties. Archers could simply point upwards, over their fellow soldiers’ heads, and could be formed into relatively dense formations.

Compare this to the tercio, a formation that is gaining popularity at the start of the Early Modern period right as firearms become widespread (tail end of the 1490s into the 1500s). It leverages the great strengths of pike and musketry (relatively low training required) to overcome their weaknesses, by massing soldiers of both types together. Musketmen provide volley fire from a "bastion" of pikes that protect them against being run down by cavalry. It would not be easy to raise such a number of trained slingers, nor to have them operate shoulder-to-shoulder.

Slings got a new lease on life as the vehicle for grenades (or in a pinch, hot coals) but ultimately, like bows, they were made obsolete by rapid advancements in firearms and plate armor.

Answer 2

Ranged attacks work especially well in volleys, as the concentrated firepower is likely to wound more people simultaneously, causing confusion and fear, and making it harder to regroup. A group of archers could draw their bows and fire simultaneously. Crossbows and firearms could do this even better. The sling was much harder to coordinate as the arming, aiming, and firing of the weapon was a single motion. People with different length arms and casting styles would fire at different moments, even if starting at the same time. Harrison

I'd like to find confirming resources, but this matches my hypothesis fairly well.

There are two issues here (I admit my ignorance; I'm an archer not a slinger)

• How tightly can you pack the troops? You can pack archers much more tightly - loading, drawing and firing takes up less space than similar activities for slingers. Slinger has to have enough room to swing that stone, and to manage the loose end of the sling afterwards. DOn't want that to slap other slingers.

• synchronized release. The act of release for an archer is ... pretty damm instant. (done right, you should almost be unaware of it). If you call "loose", the difference among archers is going to be in fractions of a second. Slingers have to wait till the stone is at the right point in the arc - unless the stones are synched, (which I find very unlikely), they're going to have to wait longer.

Others have pointed to the cost of training, which I think deserves some exploration. I'd need to explore the effort to make someone competent with the weapon vs to make someone expert. (English Longbow vs Flemish crosssbow). An interesting field for research, and I can remember the color and size of the book I'd use to start the research, but not the title or where it is on my shelves.....