zeroing

[MR TEA POT 1,287]

hi,everybody talking to a bloke yesterday he said if you zero your .22 airrifle at 10yds he says it will be bang on at 30yds is this true?just curious anyone heard this before?

[midnight 657]

it might just be mate depends on the gun and scope.

its well worth a go tho . it would only work with .22

[MR TEA POT 1,287]

it might just be mate depends on the gun and scope.

its well worth a go tho . it would only work with .22

thanks midnight i not a expert on guns being a ferreting bloke i thought the bloke was pulling me leg

[Guest baldie]

Yes mate, he,s right, the pellet travels in an arc, upon firing, so its rising as it comes out of the barrel, it crosses the line of sight at ten yards [your zero, rising up, and then dropping back through the line of sight at around 30 yards.

[mel b 2,361]

hi paul , did you try chairgun mate ? .

[MR TEA POT 1,287]

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QUOTE(mel b @ Feb 25 2006, 07:28 PM) <{POST_SNAPBACK}>

hi paul , did you try chairgun mate ? .

hi,mel how you doin i have not tryed yet computer playing up will do though.Did you zero .243 in?

 

Yes mate, he,s right, the pellet travels in an arc, upon firing, so its rising as it comes out of the barrel, it crosses the line of sight at ten yards [your zero, rising up, and then dropping back through the line of sight at around 30 yards.

hi baldie thanks for that [bANNED TEXT]

[Guest whippet]

Yes mate, he,s right, the pellet travels in an arc, upon firing, so its rising as it comes out of the barrel, it crosses the line of sight at ten yards [your zero, rising up, and then dropping back through the line of sight at around 30 yards.

 

Sorry to be pedantic, but I HATE it when people describe pellets as 'rising' when they leave the barrel. They don't rise at all, the line of sight from the scope intersects the fall of the pellet as it leaves the barrel. The adjustment lense inside the scope is actually orientated in a pretty steep downwards direction.

[Guest baldie]

You can be pedantic all you want, a projectile rises through the line of sight, then falls back through it, thats pure physics.Thats how you get two points of zero.If the line of sight intersected the FALL of the pellet, as you say, there would be only one zero point, and there isnt, there,s two.There isnt an "adjustment " lens, the crosshairs are inside a tube, know as an "erector" tube, and the adjustment dials act upon this.

[Guest whippet]

Bullets don't rise mate, THAT is pure physics.

 

''so its rising as it comes out of the barrel''

 

This is a direct quote from you, it is incorrect. Seeing as you like 'pure physics' can you please tell me why a projectile that loses energy over distance and is not aerodynamically inclined to rise (i.e no aerolon flaps) and is being affected by gravity would 'rise' as it leaves the barrel.

 

I'll say it again for good measure, a bullet does not 'rise', it only appears to from the POV of the shooter looking through the scope.

[Guest baldie]

Every diagram of a bullets trajectory shows it rising through the line of sight, then falling back through it, i dont have to explain it pal, its there in black and white, why dont you enlighten us idiots that have been at it for 35 years, as to how a bullet will have 2 zero points, and NOT rise through the line of sight and drop back through it? You cant, because its not physically possible.

 

Right, i,m gonna eat a large slice of humble pie, and apologise unreservedly to whippet here.He is technically correct, regarding the law of gravity, which he is loosly demonstrating. After a bit of research, i have come up with the drawing, i can remember seeing in all the mags etc, showing a bullets trajectory. This is where we are both correct, but in a different way. If a bullet it fired from a perfectly horizontal barrel, it can do nothing but drop, on exiting the muzzle,but this is not the way a gun is used, or zeroed. A rifle is usually fitted with a scope, which on average is 1 1/2" above the bore [line of sight]Given that a rifle is shot for zero, the line of sight will be perfectly horizontal to the target, therefore to hit the bull, the bore will be angled upward, and the bullet will be fired upward through the line of sight, and will then drop back through the line of sight, at the 2nd zero point [which is the one chosen] thus this gives two zero points.If you really want confusing, throw in some uphill or downhill shots .........bollocks, no, i,m not going there

[Guest whippet]

Every diagram of a bullets trajectory shows it rising through the line of sight, then falling back through it,

 

That's because it's easier to show the line of sight as parallel/straight when using a diagram, if it were technically correct then the line depicting the line of sight would be angled downwards.

 

i dont have to explain it pal, its there in black and white, why dont you enlighten us idiots that have been at it for 35 years, as to how a bullet will have 2 zero points, and NOT rise through the line of sight and drop back through it? You cant, because its not physically possible.

 

It does ''rise'' through the line of sight in a manner of speaking (although saying that the LOS intersects the fall of the bullet is the correct term), what I was arguing is that you stated that the bullet starts ''rising as it comes out of the barrel'' which is incorrect. It only appears to rise in relation to the line of sight.

 

I think we may have all become a little confused as to what I was saying, I was disputing this statement ''so its rising as it comes out of the barrel''. The pellet/bullet does not physically rise above the barrel, that is impossible.

 

But at the end of the day it doesn't really matter what you or I think as long as we hunt in a humane manner. I've seen too many forum arguements get petty and teddies been thrown, so shall we just do a cyber-handshake and leave it at this. I may come across as brash and forthcoming but I don't intend to be rude at all, I'm just a headstrong person and if I believe myself to be right I will fight it to the end.

Lets just be happy we have these forums to debate this kinda stuff.

[bill88 6]

Sorry to but in lads.What is actually happening is,pellets do NOT rise.From the moment the pellet leaves the muzzle it is DROPPING.The pellet flies in a downward arc,dropping more quickly as the pellet loses speed due to air resistance.If you zero the rifle at a given distance(say 30 yards)in order to hit the target zero you will actually have to shoot upwards to allow for the pellet dropping.Now if you draw a horizontal line between the scope and the target the pellet will actually cross that line twice (on the way up and on the way down)hence the scope will in effect have two zero points.My explanation is a bit crude but i hope explains the two zero point theory.

[Guest whippet]

Thanks Bill88, that is exactly what I was trying to explain. The fact that the scope is above the barrel means it is possible to intersect the fall of the pellet/bullet at 2 points.

[nutshot 0]

sounds like every is complicating matters. does it matter just get out and shoot and enjoy

[MR TEA POT 1,287]

thanks everyone,