I was curious if you make the barrel of a firearm longer, does the accuracy/range of the weapon increase in a linear fasion? Or does it become irrelevent at some point?
I notice extremes in barrel length, from proportionally long barrels (sniper rifles, anti-tank cannon) to proportionally short barrels (mortars in particular).
A longer barrel (usually) increases the sight radius. This will always improve the accuracy of the human + rifle system. But will a longer barrel improve the precision of the gun itself? I’m not sure.
A longer barrel also can increase the velocity of the bullet by giving the gun powder longer to detonate and the gasses it produces to expand further before the bullet leaves the barrel. This increased velocity “flattens” out the trajectory of the bullet, effectively making it more accurate.
Their is a limit however to the effect a long barrel has on velocity. Eventually, the gasses can expand only so much, and the bullet can only be propelled so fast. At that point, a longer barrel becomes counterproductive.
Modern firearms today use a combination of barrel length, twist rate of the rifling in the barrel, the mass of the bullet itself, as well as the speed in which the various powders burn to create the optimal bullet accuracy.
Yes and no. How’s that for an answer. Yes, a longer barrel can give greater stabilization of the projectile, but real accuracy in a firearm depends more on the correct rifling of the barrel in regards to the distance and caliber to be used , the way that the barrel is bedded in the stock, the type of ammunition used, and of course, the skill of the shooter.
I have to differ here. A flat trajectory can be desirable but has little or nothing to do with accuracy or precision.
Depending on how a rifle is used a longer barrel may or may not be good for accuracy. A long heavy barrel provides some damping mass that sometimes makes it easier to shoot with precision. Tremors or wobbles induced by the shooter move the muzzle less.
Benchrest rifles often have extremely short and thick barrels to reduce vibrations. All barrels vibrate like a whip antenna when fired. Not visibly but if the bullet exits at the peak of an oscillation a tiny displacement at the muzzle means a big error at the target. A short, fat barrel has higher frequency vibrations but with a much lower amplitude than a long, skinny barrel.
Hunters prefer light barrels so Browning has built a system with an adjustable weight at the muzzle to tune the vibration frequency. The idea is to match the vibrations to a particular ammunition load so that the bullet’s time in barrel let it exit in the middle of an oscillation, the “sweet spot.”
.22 rimfire has optimum velocity with very short barrels, 14-16" usually but rifle barrels must be at least 16" by law. Barrels are usually longer for asthetic or other reasons but some custom target rifles have very short barrels. For centerfire rifles the optimum barrel lenth for highest velocity is so long as to be unfeasable and for all practical purposes a longer barrel always means higher velocity.
The OP’s questions was
The simple answer is yes. Benchrest shooting is one thing. Military rifles are another. The OP continues:
Specifically, many US GI’s are upset with change in their primary battle weapon today. The M-16A2 used a 20" barrel and is now being replaced by the M4 carbine, utilizing a 14.5" barrel. By lopping off 5.5 inches of the barrel, the effective range and knockdown power have both been decreased. - Not cool.
So my thought is that barrel harmonics aside, a longer barrel in the hands of any soldier will do them more good than the same rifle with a shorter barrel. Do we agree on that?
I would say yes. If I am on a firing range and am using a 300 foot barrel to hit a target 300 feet away, I wager I would achieve amazing accuracy.
There are no absolutes in life. However, in laymen’s terms, the answer is yes. Seen any sniper rifles with 6" barrels?