Bullet lift
I have seen many ballistic charts that show bullet lift per yardage, then a 0 figure, then drop. What causes this? The bullet is coming out of a straight barrel, spinning. Then It goes up. Would it matter if the gun was shot on its side, or upside down? I really have no idea why this happens. You would think that gravity would act on the bullet right away. So all bullets should start at 0, and then drop. This is probably a stupid question, but I can't figure it out.
Rameleni1
Rameleni1
0
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The sights are placed on a gun, to more or less compensate for the parabala, a half moon trajectory, of the ballistic pattern that a bullet must travel. The barrel is actually aimed upward at a degree, thus your bullet is traveling upwards. It starts to be pulled gradually, by the gravity, downwards...depending on how fast...the velocity ..it is traveling. Generally speaking the super sonic, lightweights like the 45 grain, 22-250, 4000fps.and others as well, will travel the most distance, before they cross the zero...or the point blank as some call it, because it is lighter and is traveling faster...thus it somewhat defies gravity. A slower heavier bullet falls real fast. There are some real genius..here on Gunbroker, and they will respond...and correct me I am sure. I just am giving you a
very simplied, version of ballistics, in AMERICAN... NO High tech stuff.0 -
Without making a long post on the subject. The best way to learn why bullets do what the do, Lymans reloading manual (and others) explain
why there is an arch in the flight path, harmonics etc. Oh on tilting the gun (Left or right) will have a major inpact on your zero as well (Canting).
hope that helps~
"The tree of life is self pruning"0 -
I never thought of the barrel being angled up, or the sights set high. So if the barrel was level, and a round fired, it would not go up. It would go straight, and then drop?
Rameleni10 -
Starts dropping as soon as it leaves the barrel if the barrel is level. It's called gravity.
AlleninAlaska
http://www.outdoor-o-rama.com
He who dares not offend cannot be honest.
-- Thomas Paine0 -
allen is right think of it this way ..say your scope is 1.5" above the bore and say at 100 yds the bullet hits right where the cross hairs are means the rifle barrel is pointed slightly up to hit the spot where the cross hairs are on the target. in other words the bullet may go higher than line of sight but not above the bore line on sight.
if i am wrong somebody will correct me or put it in better words than i can.
doc
I dont give my guns without somebody getting hurt!0 -
ALGORE is correct the bullet starts to dror at the end of the barrel there is no lift 0 -
Aglore is correct. Gravity works on the bullet from the instant it leaves the barrel. It makes a heavy bullet drop just as fast as a light bullet. But the light bullet is moving faster so it will not drop as far by the time both bullets would travel a given distance. Jack O'Conner used to say, you could hold a rifle perfectly level out in the desert. The rifle is loaded, and your assistant is holding a bullet in his hand identical to the bullet loaded in the rifle, at the same height above the ground as the rifle. At the instant the trigger is pulled, the assistant drops bullet. Both bullets will hit the ground at the same time.
"Not as deep as a well, or as wide as a church door, but it is enough."0 -
Allen you could also use that scenario in shooting a 300 winmag and a 44 mag. Even though the 44 is a lot slower then the 300, both bullets will hit the ground at the same time. The 300 will just hit the ground several hundred yards further than the 44.
AlleninAlaska
http://www.outdoor-o-rama.com
He who dares not offend cannot be honest.
-- Thomas Paine0 -
The classic physics shooting monkeys in trees demonstration. A monkey is hanging from a tree. A hunter aligns his rifle on the monkey. At the exact instant the bullet exits the barrel, the monkey lets go of the tree and lo and behold, the monkey gets hit by the bullet.
BTW, a bullet will go above the line of sight and then hits the target where the scope is aimed on the way down. That accounts for the + values between where the yardage is 0 and the yardage where at which the scope is sighted in.
Edited by - rsnyder55 on 08/22/2002 00:08:560 -
The rifle is not aimed directly at the target. It must be angled up slightly. The bullet will cross the line of sight twice. Let's say you have a .270 sighted in at 300 yards. Just as the bullet leaves the barrel it is about an inch* below the line of sight of the scope. When you see the rifle from the side view this is evident. Out at 25 yards the bullet crosses the line of sight for the first time. The rifle is dead on at this range. Out at 150 yards the bullet is 3 inches above the line of sight. At 300 yards the bullet crosses the line of sight again. The rifle is dead on at this range. At 350 yards the bullet is 2 inches below the line of sight. At 400 yards the bullet is really dropping out of the picture and is 7 inches below the line of sight. With a rifle sighted in like this, a dead on shot may still be made at 400 yards, you just have to aim 7 inches high.If you are making a 150 yard shot at the lungs of a deer, you can aim dead on and you will kill him. If you are a police sniper making a 150 yard shot at the psycho holding a knife to a little girl's neck, you must aim 3 inches low. If you don't you will part the psycho's hair and he will kill the girl. *All numbers approximations from Jack O'Conner's book which I read 30 years ago. ps Rameleni it is not a stupid question it is complicated and there are plenty of deer hunters who don't understand it.
"Not as deep as a well, or as wide as a church door, but it is enough."
Edited by - allen griggs on 08/22/2002 07:04:21
Edited by - allen griggs on 08/22/2002 07:12:540 -
Gravity doesn't just affect the bullet as it leaves the muzzle. It is exerting force all the time. In your hand, and even in the barrel, it is kept from falling down/out because the material strengths of the flesh, bones, metal, etc.,are stronger than gravity at that point.
Gravity can't pull it thru those materials.
Think of putting a steel ball on a table edge. Now gently roll it off. It falls almost straight down.
Put the ball at the exact same place, but, now roll it harder. It will fall further away from the table. In an arc.
The more energy you put (transfer) into the ball, the further away it will land.
The distance it travels is relative to the energy supplied vs the "pull of gravity".
Happy Bullet Holes!0 -
99% of the time confusion in this area derives from that old, exaggerated, diagram used to explain trajectory in relation to line of sight. The trajectory is shown in such a curve that first time observers neglect to note that the barrel is pointed up at an angle. If you ask kids in a hunter ed. class how many think bullets rise after being fired they will almost all raise their hand, and upon questioning they will all show you the diagram in their hunter ed. book. 0
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