Why are some guns, like rifle, flintlock need to be long (102cm-154cm long) as it's hard to carry?

Answer 1

Because firearms evolve due to technological innovations, their ability to perform their function is directly related to how well the physics of it are understood. Thus, flintlock rifles had long barrels because that was the best technology could offer at the time, in order to increase the distance between shooter and target. Changes in bullet shape, firing mechanism, even alloy compositing, give each successive firearm advantages and redesigns that render the older ones obsolete and less inefficient. A lesson of this is learned in the conflict between advancing technology and outdated tactics as discovered in the Civil War, of which an excerpt, from the source below, is listed:

"The Springfield rifle-musket was a .58-caliber percussion weapon that weighed nearly 10 pounds and cost about $15. It was 58 inches long with a 40-inch barrel, and came with an 18-inch bayonet. On the negative side, bullets exited the Springfield's barrel at the relatively slow speed of only 950 feet per second (about the same as a modern .22-caliber rifle), but the gun's deadly accuracy at long ranges outweighed that shortcoming. Armed with a Springfield, a competent shooter could hit a 27-inch bull's-eye at 500 yards, the best performance to date for a standard-issue infantry weapon. A trained marksman could consistently hit a 4-inch target at 200 yards and a 6-by-6-foot target at 500 yards. At 1,000 yards, he could even hit an 8-by-8-foot target half of the time. That did not mean that the average Civil War soldier could hit anything at the more extreme distances, but improving the old smoothbore's 75-yard range by 125 yards dramatically increased the effectiveness of even the most inept infantryman...The rifle-musket and minié bullet revolutionized warfare by drastically altering the tactical balance between an attacking army and a defending one. Frontal assaults by infantry on a waiting enemy suddenly became suicidal. During the Napoleonic era, attacking infantry could safely approach to within 100 yards of an enemy line with little danger of being shot down. During the Civil War, however, because of the rifle-musket's accuracy at long ranges, stationary defenders could load and fire quickly and hit their attackers. Since advancing infantrymen could not easily stop to take aim in return, their losses were much heavier than the defenders."

Answer 2

i forget the explanation for it, but a longer barrel also cause the bullet to go faster

Answer 3

simple answer?

the longer the barrel, the more accurate the firearm

Answer 4

presumbaly, the longer the barrel, the more accurate the rifle.