Looking at several websites on sighting in I see diagrams of the line of sight through the scope and the path of the bullet from the barrel. These diagrams show the path of the bullet rising after leaving the barrel. Does the bullet actually rise above the centerline of the bore after leaving the barrel? Comments?
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scope line of sight and bullet trajectory
- Thread starter redka
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Mr Bya Lungshot
BANNED LUNATIC FRINGE
No the bullet is falling as it leaves the barrel. It “rises” because your pointed above level.
NCMTNHunter
Senior Member
Yes and No. If your barrel is dead level the bullet starts dropping as soon as it leaves the barrel. If you were to drop a bullet from the center line of a level barrel at the same time you fire a bullet from the barrel they will hit the ground at the same time. The reason the bullet rises above the line of sight is because the barrel and line of sight are not parallel to each other. If your line of sight is level the barrel is pointed slightly upward. The only reason the bullet rises is because the barrel is pointed upwards.
bullgator
Senior Member
Your scope is mounted at a slight downward angle. Your bullet will cross your like of sight at two points. First as it intersects crossing from below to above line-of-sight and again as it drops back below line-of-sight.
Railroader
Billy’s Security Guard.
This, right here... It's that simple.
jrickman
Senior Member
Think of it as throwing a bullet rather than firing it and it will all start to make sense. Once you have that visual then start thinking about throwing a baseball inside a building. You can't arc upwards much, so if you want to throw farther you have to throw harder/faster. It's all about outrunning gravity. Concepts like MPBR become simple once you start thinking about it this way.
Throwing the bullet is a good example. If you had to throw the bullet 100 yards to a target the high point of the trajectory would have to be above your eye unless you had a truly special arm. Your eye to the target is the same as the line of sight through the scope would be. Now, did the bullet rise? Yes and no. Gravity started acting upon the bullet as soon as you let it go. You hat to throw it at an up angle in order to overcome gravity long enough for the bullet to travel tot he target.
It is all so very simple. It is the explaining of it that is hard. Once you understand the concept perhaps you can help simplify the explanation. LOL
It is all so very simple. It is the explaining of it that is hard. Once you understand the concept perhaps you can help simplify the explanation. LOL
Railroader
Billy’s Security Guard.
All bullets travel in an arc.
All scopes "look" in straight lines, intersecting said arc twice...
Fired from level no bullet will rise above the bore's axis.
Velocity has zero effect on gravity.
All scopes "look" in straight lines, intersecting said arc twice...
Fired from level no bullet will rise above the bore's axis.
Velocity has zero effect on gravity.
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Bigbendgyrene
Senior Member
Another key factor contributing to what appears to be magical bullet rise is the distance at which you're zeroing your rifle.
Take for example someone firing a .270 in an open area who may be looking to take shots out to 250 yards.
By setting their zero at 200 yards, using a 140 grain bullet they'll be approximately (know this will vary just a bit / just using for example!) 1.5 inches high at 100 yards and 2.5 inches low at 250 yards. So with the 200 yard zero, they can target a broadside vertical center-mass double lung shot over the front leg and assuming they keep their aim true on the trigger-pull will have a kill shot without the need for ANY elevation adjustment.
So the above shared, had they zeroed the same .270 at 100 yards a shot at 200 yards would be about 1.5 inches low.... so to zero at 200 it resulted in the bullet having to be higher at 100 yards. The end result is that a chart for a 200 yard zero makes it look like the bullet is lobbed up and rising when in fact the "lob" is almost all due to adjustment for the actual drop.
Worth noting, the shorter the distance the ballistics chart shows, the more dramatic the "lob" appears.
So here's the ballistic chart for the .270 zeroed at 200 yards only showing the trajectory out to 300 yards... looking at this chart it looks like the bullet travels some really crazy curved path you'd never imagine a shot taking.
Whereas this is the ballistic chart for the SAME EXACT round zeroed at 200 yards but with the bullet drop shown out to 800 yards. Sure looks to be way flatter in those first 300 yards and with what little "lob" is apparent being mostly due to adjustment upwards to hit zero at 200 yards. By viewing the ballistic chart much farther out you get a better perspective of what the actual bullet path looks like, with the bullet dropping at a relatively slight rate through the initial 200 yards of travel as compared to the ever-increasing more dramatic rate of drop as the bullet slows and gravity has increased effect. The shorter range ballistic charts are very helpful in choosing what distance to zero and is why so many of us like looking at them, but the longer distance ballistic charts do a MUCH better job painting an accurate picture of how the bullet actual travels in my opinion, even if not quite as practically useful in choosing zeroing distance.
Take for example someone firing a .270 in an open area who may be looking to take shots out to 250 yards.
By setting their zero at 200 yards, using a 140 grain bullet they'll be approximately (know this will vary just a bit / just using for example!) 1.5 inches high at 100 yards and 2.5 inches low at 250 yards. So with the 200 yard zero, they can target a broadside vertical center-mass double lung shot over the front leg and assuming they keep their aim true on the trigger-pull will have a kill shot without the need for ANY elevation adjustment.
So the above shared, had they zeroed the same .270 at 100 yards a shot at 200 yards would be about 1.5 inches low.... so to zero at 200 it resulted in the bullet having to be higher at 100 yards. The end result is that a chart for a 200 yard zero makes it look like the bullet is lobbed up and rising when in fact the "lob" is almost all due to adjustment for the actual drop.
Worth noting, the shorter the distance the ballistics chart shows, the more dramatic the "lob" appears.
So here's the ballistic chart for the .270 zeroed at 200 yards only showing the trajectory out to 300 yards... looking at this chart it looks like the bullet travels some really crazy curved path you'd never imagine a shot taking.
Whereas this is the ballistic chart for the SAME EXACT round zeroed at 200 yards but with the bullet drop shown out to 800 yards. Sure looks to be way flatter in those first 300 yards and with what little "lob" is apparent being mostly due to adjustment upwards to hit zero at 200 yards. By viewing the ballistic chart much farther out you get a better perspective of what the actual bullet path looks like, with the bullet dropping at a relatively slight rate through the initial 200 yards of travel as compared to the ever-increasing more dramatic rate of drop as the bullet slows and gravity has increased effect. The shorter range ballistic charts are very helpful in choosing what distance to zero and is why so many of us like looking at them, but the longer distance ballistic charts do a MUCH better job painting an accurate picture of how the bullet actual travels in my opinion, even if not quite as practically useful in choosing zeroing distance.
Railroader
Billy’s Security Guard.
^^^Nice write up!
nmurph
Senior Member
100% to the point and accurate.
Exactly...several other posts obfuscate the answer
lonewolf247
Senior Member
Short answer, bullets don't rise, and are subject to gravity, from the time they leave the barrel. Others have explained why.
The ballistic trajectory charts are really handy though. I use them to sight in most of my deer rifles, for MPBR, for each given caliber. That way, I can aim directly on my target, out to a certain range, and don't compensate for bullet drop, in the path to that distance.
Bigbendgyrene gives a more detailed post. Many standard calibers can use the 200 yard zero, and you should be good out to 250 yards or so, depending on the caliber and load. It's a good way to go, if you see yourself shooting to 200 yards and beyond. Unless, all of your shots are under 100 yards, then the 100 yard zero, makes sense.
The ballistic trajectory charts are really handy though. I use them to sight in most of my deer rifles, for MPBR, for each given caliber. That way, I can aim directly on my target, out to a certain range, and don't compensate for bullet drop, in the path to that distance.
Bigbendgyrene gives a more detailed post. Many standard calibers can use the 200 yard zero, and you should be good out to 250 yards or so, depending on the caliber and load. It's a good way to go, if you see yourself shooting to 200 yards and beyond. Unless, all of your shots are under 100 yards, then the 100 yard zero, makes sense.
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BriarPatch99
Senior Member
The bullet never rises ...the bullet FALLS twice across the line of ...once some where around 25 yards and again where you have your target ....
The bullet is always falling once it leaves the barrel ....
The water out of a hose is a good example ... if you want the stream to hit a bucket at ten yards ....you have to point the hose higher up.... the water is always falling once it leaves the hose ...
NCMTNHunter
Senior Member
That is the exact point I was trying to make with that sentence. The only time a bullet rises in relation to the earth is when it is fired at an upward angle. In which case it does rise in relation to the earth and line of sight.
If you shoot with a level or downward angle then the bullet is falling relative to the earth both times it crosses the line of sight but it is still rising in relation to the line of sight at the first crossing.
BriarPatch99
Senior Member
No ...it is not rising ..... It is falling .....a bullet does not rise ....
Once it leaves the barrel it is always falling(until it hits the ground or something stops it)
Sorry ..... It crosses the line of sight twice .....but both times the bullet is falling the whole time ....
Once it leaves the barrel it is always falling(until it hits the ground or something stops it)
Sorry ..... It crosses the line of sight twice .....but both times the bullet is falling the whole time ....
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lonewolf247
Senior Member
I think most here understand the principal, it's just the terminology being used. When you use the word "rise", it implies that the bullet is defying the laws of gravity. Most here know that's not the case, so rise is the wrong word.
If your hunting squirrels with a .22 LR, and you shoot up into the tree. The bullet is not rising. It's being shot on an upwards angle. It's subject to gravity, and it will come down.
If your hunting squirrels with a .22 LR, and you shoot up into the tree. The bullet is not rising. It's being shot on an upwards angle. It's subject to gravity, and it will come down.
This^^^^^^^^As noted.. Bullets can never rise
NCMTNHunter
Senior Member
So if you aim at the sky perpendicular to the earth and pull the trigger, the bullet isn’t rising, gaining elevation?
lonewolf247
Senior Member
I just think rising is the wrong word. It takes a force to make it gain elevation. If you set a bullet on the floor, and it magically started rising up to the ceiling, that would be rising.
I think you understand the principal, it just gives the wrong idea, when someone says, a bullet rises as it leaves the barrel, then it starts to come back down.
I think you understand the principal, it just gives the wrong idea, when someone says, a bullet rises as it leaves the barrel, then it starts to come back down.
NCMTNHunter
Senior Member
when you point the hose up to hit the bucket 10 yards away, just like you point a barrel up to hit a target 300 yards away, the water isn’t rising to the top of the arch before it starts falling? What am I missing?
