Now that we are using muskets we should know a little more about them. Such as what kind of killing power and accuracy they had.
"It will kill the armed of proofe (men with "proofed" armor) at ten-score yards (200 yds.), the common armours at twenty score, and the unarmed (unarmored) at thirty-score, being well used in bullet and tried powder." -Humphrey Barwick, 1591.
Modem experiments with seventeenth century style guns have confirmed some of these claims. In optimum conditions, muskets of our period are potentially lethal, to a man without armor, as far out as 1000 yards. -Assuming of course you could actually hit him. Due to limited accuracy, tactics of the time recommended nor firing until the enemy was about 200 yards away.
"When fired at 12 scores (240 yds) at either horsemen or footmen that are in motion, they shall work no great annoyance, by reason that the bullets.., doe naturalie mount and flue uncertainly." -Sir John Smythe, 1590.
In fact, Smythe wrote in his Certain Discourses that a practice of veteran Spanish infantry was to have a few men begin firing at 200 yards to fool the enemy into wasting ammunition and fouling their weapons sooner. The real volleys would occur not until 20 yards he claimed. By our time the firing might still begin about 200 yards, but the firing in earnest would wait unto 100-120 yards. A massed volley with all your musketeers firing at once would be saved until 20 yards, or so, and only to repell a serious cavalry threat, or just before a push of pike, since it could only be done once and then all your shot would have to pause to reload, or fight hand-to-hand.
Of course one of the arguments of the time was why abandon the bow and arrow with its rapid rate of fire and relative accuracy for a slow-to-reload, not-terribly-accurate firearm and tool of the devil? One, the tactics of the time didn’t require that much accuracy. Two, you can also train a someone to adequately shoot a matchlock at a big block of men in a matter of days. Whereas it takes time to build the muscles and skill of archer.