@tizz That's a smoothbore arquebus you know. It'll throw a ball couple'a hundred meters easy, sure, but you know what empirical experiments then AND now say about the accuracy?
A skilled shot has roughly even odds of hitting a standing man at hundred paces, that's what. See
ballistic effective range is a completely different thing from
accurate range; similarly any halfway decent modern pistol cartridge will readily send a bullet hundreds of meters downrange, but the practical distance at which a handgun will actually
hit something in combat conditions caps at about ten give or take.
Rifing was invented and is used for a
reason; without centrifugal stabilisation the ball will just start veering off into a random direction and there's literally nothing even the best shooter can do about that because PHYSICS, SON. By the hundred-meter mark it can deviate a good meter plus from the point of aim, easy. There's very good reasons why gunpowder warfare consisted of large bodies of men operating as giant shotguns.
Doesn't really help that the Japanese guns like Our Hero's were still using (and never really graduated from) the old-style stocks that couldn't be held against the shoulder for a third contact point and better recoil absorption (both of which are of some real relevance to accuracy), ofc. By the end of the 1500s Euro designs had begun stabilising on a more modern pattern and the older type was relegated to small-caliber hunting and sport pieces - in such contexts it was apparently felt that bracing against the shoulder was cheating and a good shot should get by without.
And ofc even cheap mass-produced ("munition") cavalry body armour was required to stop an arquebus ball from about ten-fifteen paces (and pistol from some five - in cavalry fights muzzles were routinely pushed into direct contact before firing for this reason); the kind of expensive, tailored good stuff wealthy senior rankers who bought their own kit wore was naturally stronger still.
Also, for the record, by this date Japanese firearm tech was falling
way the fuck behind the curve anyway. They basically got stuck on matchlock smoothbores until mid-1800s Western imports; Europeans had worked out rifling and more advanced mechanisms (ie. the wheellock) already over a century ago and were at this time poking at early versions of the flintlock ("firelocks" were standard issue for artillery guard detachments by the Thirty Years' War since troopers wandering around that much gunpowder with lit slowmatch was a self-evidently bad idea) - the French compiled the various designs floating around into the definitive model that basically stayed in use as-is until the early-mid 1800s invention of the caplock in the second half of the century.