Question: Why didn't line infantry tactics try to keep up a constant volley of fire?
It wasn't due to a lack of knowledge. From the mid sixteenth century until WWI volley fire was the predominant way infantry discharged their weapons on the battle field (groups of men trained to fire together). From early on in that period tactics to kept up a continuous or rolling volley of fire were well known to European armies. Many of the American Revolutionary leaders such as Generals Washington, Horatio Gates, James Clinton and others were experienced officers in the British Army prior to the American revolution and thus would have been aware of these techniques and how to train and command troops to utilize them to their maximum effect. Still the United States forces in the revolutionary war benefitted greatly after Baron von Steuben in 1777 introduced the most modern of these techniques known at the Prussian or Alternate method. It utilized specialized hardware like the ram rod and fewer rows or platoons of men with a condensed loading cycle to increase the rate of fire. Thus I think your question boils down to why weren't these continuous fire tactics used exclusively in battle for the 250 - 300 years while volley fire was in favor. And more specifically why wasn't it used more by the British and Americans during the American Revolution given the British were arguable the best trained and accomplished army of their day and given the Americans were aware and trained in these same techniques.
The answer to the former question is, continuous salvo's simple were not always superior. If you had six rows of men all coordinating their fire in order to keep up a constant rate of fire, (six rows were the norm of the two most regularly used constant fire systems early on); it limited overall rate of fire. Early on well trained musket men could shoot 1 or 2 times a minute ( 2 or 3 times under the Prussian Alternate Method taught by von Steuben to the Americans). Platooning them reduced the first volley to 1 sixth the number of total guns. Continuous fire had a psychological benefit but as far as getting as much lead down range as quickly as possible it was not optimal. In staggering you reduced your overall fire and overall concentrated fire was the game winner in most cases with muskets. This is because muskets were not accurate. Muskets were most effective when shot by many men in a volley and all at the same target at relatively close range. The more muskets firing the better.
What would put more lead down field fastest. 600 men all shooting at once.. reloading say twice over a minutes time and each time all shooting again.. Or 600 men shooting 100 at a time, shifting to the back six paces, as someone behind shifted forward, and then maybe as much as 10 seconds latter 100 more guys shooting. It would take you six volleys in order to match the devastation of the first volley of your enemy. Think of all the waste of the loaded muskets laying on the ground beside dead or wounded men after that first or second overwhelming volley they would endure!
Also after you received / endured your enemy's total volley, at relatively close range( because the musket wasn't useful at anything but short range (100 yards was it's maximum effective range, as mentioned by Tom earlier 50 yards distance was better and often favored)... next up was generally a bayonet charge, disrupting your third or fourth volleys.
For the American Revolution there were specific reasons continuous volleys tactics which both sides were aware of, were seldom used. First off because the British didn't believe the colonials were much of a threat and didn't deem it necessary to use their best tactics against a colonial opponent. The British opted for a more expedient tactic which brought them soonest into close range with the colonials. One volley, bayonet charge. The colonials did not have bayonets, and generally used irregular weapons. The colonials were also undisciplined. All of these properties put the colonials at a disadvantage when bayonets were used. Lastly the colonials had nearly no calvary to intercede or flank a bayonet charge. The abbreviated British tactics capitalized on all of these advantages.
After the revolutionary war, the Battle of New Orleans in the war of 1812, where the British lost more than 2000 men to the outnumbered Americans 13; demonstrated one liability of adopting a centrally commanded complex firing systems against an unchivalrous enemy. Officers can't give the important and complex firing commands if they're dead.
There were many different techniques used to coordinate infantry fire.
They were like hair or clothing styles. Different countries favored different techniques and their strengths and limitations were discussed and debated among professional soldiers from different countries. A commander would be aware of which technique his enemy favored and might favor an alternate technique to maximize the weaknesses of his enemies approach.
In the matchlock period their were primarily three methods for infantry to discharge their weapons. "The traditional Dutch method or "counter march" /continuous", "Swedish salvee / non continuous" and the “Swede’s way / also continuous”
"The traditional Dutch method" also called the counter march or caracole. Involved six rows which fired by row(rank). Each row would advance, fire and then retreat to the back to reload. Problem was this formation wasn't particularly good when retreating, or maintaining it's position. Also it wasn't good directing fire as it required some firing lanes be used for paths of retreating or advancing soldiers. So you had to be advancing and you had to be facing your target.
"the Swedish Salvee" also involved six ranks only the ranked doubled up into 3 lines, front middle and back. Then all three ranks fired at the same time into one devastating volley. Usually followed by a bayonet or pikemen's charge. This method was used extensively during the English Civil War (1642-1651). The obvious disadvantage was that all the muskets were discharged at the same time and left the troops vulnerable as they were reloading. The advantage was your enemy endured one massive total expenditure of your muskets, and thus it was efficient in that no loaded muskets were left unfired after the first salvo.
The Third Method was the "Swede's Way", oddly enough a variation of the Dutch method favored by the swedish general Gustavus Adolphus. It involved a line of musket men being deployed in a checkerboard layered manner, three deep. So each man had a clear path to the front. The first layer would fire and retire, followed by the second layer, and then as you would expect the third layer. The Battle of Breitenfeld, on September 17, 1631, saw this tactic being employed. In 1675 King Charles II’s added this method to the English Military Discipline. Advantages included clean lines of advance. It could be used moving forward, backwards or stationary. Disadvantages is it didn't mass fire particularly well given it required troops to be spread out in essentially one multi level line, and it had problems with directing fire other than straight forward.
By the end of the seventeenth century matchlocks went away and flint locks became the primary weapon. Pikemen previously used with musket men in a 2-1 ratio; went away in favor of more musket men with early plug bayonets. ( muskets could not be fired when the plug bayonet was used because it obfuscated the muzzles when deployed. )
So now people took the three previous method and innovated from them.
In 1708 the Duke of Marlboro innovated off of the Dutch system to create what we call today platoon fire. He separated his division into battalions and the battalions down to 18 platoons. Each platoon employed the dutch system but each platoon could be directed independently and placed strategically around the battle field to provide supporting fire or suppressing fire or compounding fire against an enemy position.
- very flexible and adaptable.
- high degree of control
- Platoon firing allowed the fire to be directed, if necessary, obliquely to the left or right and not just directly to the front of the battalion.
- enemy came under concentrated and continuous fire once the action opened
- One-third of a battalion would always be loaded and ready to deal with an emmergency.
Very complicated to train and command.
In the mid 18th-century The "alternate system" became prominent. This was based upon new Prussian loading techniques which greatly improved the speed at which muskets were loaded. Both the British and Americans used this technique during the American Revolution, although not primarily.
Baron von Steuben introduced this method to the American Army famously at valley forge and it greatly increased the colonials rate of fire. He wrote the first infantry training manual for the United States, called the "blue book" which remained in service through the war of 1812.
Overall though the British didn't use standard european volley fire techniques in the American Revolution. Several reasons:
- the preference for the bayonet against a skittish opponent
- the need to fight over broken terrain and extended frontage
- the lack of American cavalry, which did not require the British to reserve a portion of their fire at all times to deal with sudden emergencies—hence the preference for a single general volley immediately prior to the bayonet charge.
During the Battle of New Orleans and the War of 1812, Andrew Jackson's sharpshooters targeted British officers from the onset of the battle. The subsequent death of the commanding British officer and many of his intermediates left the British army, fresh off the battle fields of Europe where they had defeated Napoleon at a decided disadvantage. Over 2000 British soldiers died to 13 Americans in this miraculous victory against what was widely considered the finest army in the world. Sometimes too much central control and the flexibility that grants you is a liability.
Overall volley fire should have been abandoned with the advent of the Minie-Ball but it wasn't. The Minie-ball was a round which allowed riffles to be loaded as quickly as muskets. It was an oblong round with a hollow tail which expanded when it fired. The expansion allowed the round to pick up the riffled barrels and thus dramatically effected accuracy. The real innovation was though they expanding round allowed it to be smaller than traditional riffle rounds in diameter, which vastly improved loading speed. Prior to this riffles were slower to load because the round needed to be larger to pick up the barrel grooves. today's riffles and even riffled pistols utilize rounds larger in diameter than the barrels of the weapons which fire them. The powder forces the compaction of the round in order to pick up the riffled ridges in the barrel. It's also why rounds are made typically of softer medals like coper or lead. Anyway the Minie-ball which became prominent in the American Civil war and Crimean War, dramatically increased the lethality and range of infantryman which up to this point primarily used the fast loading but highly unaccurate muskets and only used the slower loading rifles for specialized troops like sharp shooters. Thus in the American Civil war volley fire by rows of men all lined up on the battle field, and the resulting counter fire were devastating.
Amazingly enough even with breach loaders and repeating riffles volley fire continued to be the primary way infantrymen fought up until WWI and the advent of the machine gun. With the advent of the machine gun massing troops for one strong volley or even continuous rolling fire was no longer just stupid, it was suicide. WWI is when volley fire finally slipped into the pages of history.