open sights

[Fishaholic]

i have a  3006 and its open sights and i need to sight in. i shoot 150 yards at the most any advice on were to sight it in at yard wise thanks

[Swannytheswan]

100 yds and then you calculate bullet drop from there....if you only shoot 150 its not dropping far anyway and there is negligible rise/drop under 100yds

[bigsads]

zero at 100, figure at 150 you might be 1" high

[Eli346]

 I'd start at 25 yds and get it centered with a good group. You'll be a lot more confident in your rifle and it will also be good out to about 200 yds from that.

[Fishaholic]

i use to have a scope on it but it fogged up so i put open sights in it. i may be moving to mt and need the rifle dead on not sure how far i would  be shooting but i need to have it super accurate because you can get 6 deer tags and i may  want to thin out 2 or 3 deer for a herd at a time lol

[JackOfAllTrades]

zero at 100, figure at 150 you might be 1" high

WRONG!
 
The concept of there being a difference or rise in trajectory relative to a straight visual line of sight, on a scoped rifle holds true, but the OP said Iron Sights.  That lowers the focal point by more than an inch above center bore of the barrel, which might not seem to be much, but the effects down range are tramendous.  If you sight (iron sights) in at 100yds to be zero, then your bullet point of impact beyond 100yds will be below target. 
 
-Steve

[Bob33]

A 100 yard zero means a bullet will first cross the line of sight at a distance less than 100 yards. The second zero will be 100 yards in this instance. From that point forward it will be below the line of sight.

[JackOfAllTrades]

A 100 yard zero means a bullet will first cross the line of sight at a distance less than 100 yards. The second zero will be 100 yards in this instance. From that point forward it will be below the line of sight.

Yes and no..    It actually fly's flat enough out to 100yds. While it does arc in flight, I think we're splitting hairs to say that a bullets flight path may actually move above top of bore center before it starts dropping. A heavy slow moving 300gn 44mag would have a more pronounced arc of trajectory relative to line of sight/and barrel bore angle.  Lets not make everyone think that the bullet actually rises out of the barrel.
 

 
Anyone not ranging their target, could just sight in a 200yd zero with whatever sights, and still have point of impact in an 8" kill zone along the whole distance from muzzle to about 250yds with a 30-06.
 
-Steve

[Fishaholic]

alright i think i may sight it in at 200  with the scope  at 200 yards the 180s i use are dead on  at 100 they were an inch low

[huntingfool7]

A 100 yard zero means a bullet will first cross the line of sight at a distance less than 100 yards. The second zero will be 100 yards in this instance. From that point forward it will be below the line of sight.

Yes and no..    It actually fly's flat enough out to 100yds. While it does arc in flight, I think we're splitting hairs to say that a bullets flight path may actually move above top of bore center before it starts dropping. A heavy slow moving 300gn 44mag would have a more pronounced arc of trajectory relative to line of sight/and barrel bore angle.  Lets not make everyone think that the bullet actually rises out of the barrel.
 

 
Anyone not ranging their target, could just sight in a 200yd zero with whatever sights, and still have point of impact in an 8" kill zone along the whole distance from muzzle to about 250yds with a 30-06.
 
-Steve

Per your drawing- a 100 yard zero with an 30-06 will be dead on at 400?  That does not make sense.
With a 100 yard zero, the bullet will cross the line of sight at 17-21 yards, be slightly above the line of sight between there and 100 yards.  From 100 yards on, it will be falling.

[JackOfAllTrades]

Huntingfool7....  measure the bullet drop at 400yds from the immaginary line of the barrel bore to the point of impact. (not the line of sight)  Maybe the next illustration will make sense. (I'll also correct myself in my response to Bob, when I said we'd be splitting hairs for bullet drop out to 100yds. It is over two inches drop if the bore is the zero reference. -that's what I get for posting while I'm at work and not referencing the book. And if the OP is printing 2" groups with iron sights at 100yds, this is relavent.)
 
-Steve
 
 

[Wazukie]

Pretty simple here.  If using Iron sights, zeroed at 100 yards, 180 gr 2700 fps - bullet will not rise nor drop more than .5" out to 100 yards.  at 400 yards its about a 36" drop.  You would be able to shoot out to about 200 yards and still hit an 8" kill zone with no hold over.  Now you have to remember that this is all considering perfect conditions and shooter. 

[huntingfool7]

JackOATrades- I'm not trying to split hairs, nor trying to start a fight .  Just saying your trajectory drawing is a long way from accurate.  Even with open sights the bore is about 1/2" below the sighting plane.  Perhaps that is the root of this error. 
The drawing you posted shows that when sighted in at 100 yards the bullet is dead on again at 400 yards.  Per your second trajectory chart with a 400 yard zero the bullet is +7.39 @ 100 yards and +11.16 @ 200 yards.
A good friend of mine is convinced you can hold dead on out to 4 or 500 yards with an aught six.  That is only true if your range estimation is a little off 

[JackOfAllTrades]

I didn't draw it, I stole it off the internet. Take the line of sight that is drawn out if you want.. Follow the bore! Look down the bore. Look across the top of the bore. The illustration may not be perfect, but it does show the arc of the bullet trajectory with reference to the rifle bore. That simple!
 
-Steve

[Bob33]

A 100 yard zero means a bullet will first cross the line of sight at a distance less than 100 yards. The second zero will be 100 yards in this instance. From that point forward it will be below the line of sight.

Yes and no..    It actually fly's flat enough out to 100yds. While it does arc in flight, I think we're splitting hairs to say that a bullets flight path may actually move above top of bore center before it starts dropping.

"Splitting hairs", but here is what my software shows for a 30-06 180 grain bullet going 2700 ft/second at the muzzle with a BC of .4, a sight height of .5 inches, and a 100 yard zero. The bullet first crosses the line of sight at approximately 20 yards, reaches a maximum height of approximately .42 inches at 60 yards, and then drops relative to the line of sight, crossing it again at 100 yards.

Yards   Drop
0    -0.50
10    -0.22
20    0.01
30    0.19
40    0.32
50    0.39
60    0.42
70    0.40
80    0.32
90    0.19
100    0.00
110    -0.24
120    -0.54
130    -0.90
140    -1.32
150    -1.79

[huntingfool7]

I didn't draw it, I stole it off the internet. Take the line of sight that is drawn out if you want.. Follow the bore! Look down the bore. Look across the top of the bore. The illustration may not be perfect, but it does show the arc of the bullet trajectory with reference to the rifle bore. That simple!
 
-Steve

Like many things found on the internet, it is inaccurate.  If you take the sight plane out of the drawing you can not have the bullet trajectory impact at 100 and 400 yards (and be on at both ranges).

Further if you take the line of sight out of the equation, the only place that the bullet is in line with the barrel is directly in front of the barrel.  The bullet will impact low at 100 yards then continue to drop from there.  Ending about 24" low. 
The higher your sights are above the bore, the flatter shooting your rifle will appear on dropping chart.

I am very comfortable with admitting when I make a mistake.  I view that as a personal positive trait.

I notice in your post #5 you state "If you sight (iron sights) in at 100yds to be zero, then your bullet point of impact beyond 100yds will be below target. 
 -Steve"

I wonder if we're viewing different parts of this thread.  Post #5 is an accurate statement.  I have been looking at and referencing the posted trajectory chart that shows the bullet impacting dead on both at 100 and 400 yards.  Don't know what cartridge that refers to but it's not an 30-06

[JackOfAllTrades]

None of what I list here is 'dead on at 400yds' if sighted in to be zero'd at 100. It is 30 some inches low at 400yds. I don' t know what optical illusion you're seeing.
 
Fine! I've removed the graphic if it is too confusing.  What I liked about the graphic is that it depicted the angle of the bore relative to getting the bullet path enitial arc to zero at 100yds.  Your visual sight plane does impact or pass through the arc two times.  This isn't rocket science..  And it ain't my first rodeo.
 
The OP has stated that he'll just sight in at 200yds..  Lets leave it at that.
 

-Steve

[huntingfool7]

Not confused at all...however I am very sorry to have offended you.  Best wishes and I hope you have a Merry Christmas.

[Fishaholic]

jackofalltrades  thank you for the picture. like i said i will sight it in at 200 and i should be good up to 300 yards if i see were it shoots. now just to wail til it stops snowing so i can sight it in. thank you everyone and merry christmas

[Bofire]

 :)But don't forget that once you are sighted in, if you shoot your rifle upsidedown the bullet won't fly as far.
Carl

Happy Ho Ho and Merry New Year!

[huntingfool7]

Bo, That is a funny thought.  If said gun is sighted in to hit dead on at 100 yards then was turned upside down.  The bullet would cross the line of sight (between 17 and 21 yards) and continue to drop.  The bullet would only cross the line of sight once in that case hitting low at 100 yards.

[BULLBLASTER]

Is that also the case if the shooter and target are upside down too? Or just the rifle?  what if the shooter is upside down with a right side up rifle shooting a sideways and inside out target? 
 

[Bofire]

  The shooter really should be perpendicular to the rate of the bifelinial complex of drop of the cortex( X )the rate of contour of the ogive. other than compromising the factor of the grooves enhancing the HP expansion factor the equation is straightforward.
In other words never look thru a right handed optical device left eyed which of course cannot be done with open sights and always consider the axis of the earth and direction of orbit. ( hint the sun rises? in the East.)
Sincere God of all Knowledge Worth Nothing (knowing)
Carl

[Arnbo]

This is one of the reasons Ireally like this Forum.
 You always get every angle and every possible answer.
You guys are the best! I have learned a lot in the short time of being a member.
Happy New Year......
       Arnbo