TonyD
One Shot One Maggie's Drawers
So as not to hi-jack the thread on "AR15 barrel length" I decided to put down a few notes here.
Maybe in a vaccum but it does in the real world of shooting. It's a much too complicated issue to let it go at the quote above.
We've all seen the "experiments" of clamping a gun in a vise and sawing off a half an inch at time and shooting groups with no consistency in group size. Most of these are done at 50 or 100 yards. So when is the last time you hunted, competed or plink'ed with your rifle or handgun clamped in a vise?
Barrel length increases or decreases velocity incrementally. How much change depends on the caliber and load. Velocity has a direct affect in accuracy as to how long the bullet is exposed to environmental conditions during flight before reaching its point of impact. In other words, how long gravity, thermals, and wind have to change a bullets path from a straight line. The difference between a 16" and a 26" barrel can be significant. Bullet design also has an impact.
Higher velocity rounds are "flatter" and therefore have less bullet "drop" at a given distance. Bullet drop has no impact whatever on accuracy, per se. It only affects MPBR (often confused with accuracy). If a bullet drops 10 inches at a thousand yards or 100 inches makes no difference.
In the case of using iron sights a longer sight radius can have a dramatic impact on accuracy. Sight alignment is one of the most crucial aspects of marksmanship fundamentals. A longer sight radius allows much less error in sight alignment. Proper sight alignment with improper aiming point will still deliver the round point-of-aim, point-of-impact. Improper sight alignment won't be close to anything resembling point-of-aim, especially at any distance at all.
Every bullet design-weight-caliber, barrel twist, has a minimum barrel length to fully stabilize the bullet before it exits the muzzle. I challenge anyone to shoot a 90 grain .233 from a 14.5" carbine at a thousand yards and be as accurate as a 24".
This may be true for someone who's never shot past 100 yards with anything. I can consistantly hit a man-size torso at a thousand yards with my NM AR15. I would not be able to do the same with a "gov. profile" carbine, (yes, I've tried).
Barrel profiles do have a major impact on accuracy as it affects the harmaonics and heat build up. Thinner barrels heat much more quickly than heavier barrels. As heat increases the harmoncis (the figure eight movement the barrel exhibits as the round is fired) changes because the hotter the metal is the easier it is to manipulate, i.e. bend.
Another factor concerning accuarcy is the barrels "tight" spot. Most precision (match) barrels are guaranteed to be straight within 5 tenths, or .0005". That means the diameter of the barrel will flucuate down its length. Accuracy is maximized when the tight spot (the narrowest portion of a particuler barrel) is at the muzzle.
All of these things, and more, have to do with accuracy. Barrel length is one part of the overall picture, but it is a part.
Just because YOU (general term meaning anyone) can't hit a bull in the ass with a snow shovel, doesn't mean that proper equipment won't maximize MY accuracy.
Maybe in a vaccum but it does in the real world of shooting. It's a much too complicated issue to let it go at the quote above.
We've all seen the "experiments" of clamping a gun in a vise and sawing off a half an inch at time and shooting groups with no consistency in group size. Most of these are done at 50 or 100 yards. So when is the last time you hunted, competed or plink'ed with your rifle or handgun clamped in a vise?
Barrel length increases or decreases velocity incrementally. How much change depends on the caliber and load. Velocity has a direct affect in accuracy as to how long the bullet is exposed to environmental conditions during flight before reaching its point of impact. In other words, how long gravity, thermals, and wind have to change a bullets path from a straight line. The difference between a 16" and a 26" barrel can be significant. Bullet design also has an impact.
Higher velocity rounds are "flatter" and therefore have less bullet "drop" at a given distance. Bullet drop has no impact whatever on accuracy, per se. It only affects MPBR (often confused with accuracy). If a bullet drops 10 inches at a thousand yards or 100 inches makes no difference.
In the case of using iron sights a longer sight radius can have a dramatic impact on accuracy. Sight alignment is one of the most crucial aspects of marksmanship fundamentals. A longer sight radius allows much less error in sight alignment. Proper sight alignment with improper aiming point will still deliver the round point-of-aim, point-of-impact. Improper sight alignment won't be close to anything resembling point-of-aim, especially at any distance at all.
Every bullet design-weight-caliber, barrel twist, has a minimum barrel length to fully stabilize the bullet before it exits the muzzle. I challenge anyone to shoot a 90 grain .233 from a 14.5" carbine at a thousand yards and be as accurate as a 24".
This may be true for someone who's never shot past 100 yards with anything. I can consistantly hit a man-size torso at a thousand yards with my NM AR15. I would not be able to do the same with a "gov. profile" carbine, (yes, I've tried).
Barrel profiles do have a major impact on accuracy as it affects the harmaonics and heat build up. Thinner barrels heat much more quickly than heavier barrels. As heat increases the harmoncis (the figure eight movement the barrel exhibits as the round is fired) changes because the hotter the metal is the easier it is to manipulate, i.e. bend.
Another factor concerning accuarcy is the barrels "tight" spot. Most precision (match) barrels are guaranteed to be straight within 5 tenths, or .0005". That means the diameter of the barrel will flucuate down its length. Accuracy is maximized when the tight spot (the narrowest portion of a particuler barrel) is at the muzzle.
All of these things, and more, have to do with accuracy. Barrel length is one part of the overall picture, but it is a part.
Just because YOU (general term meaning anyone) can't hit a bull in the ass with a snow shovel, doesn't mean that proper equipment won't maximize MY accuracy.
