HuntingNet.com Forums

HuntingNet.com Forums (https://www.huntingnet.com/forum/)
-   Guns (https://www.huntingnet.com/forum/guns-10/)
-   -   Sighting In 7mm-08 (https://www.huntingnet.com/forum/guns/37541-sighting-7mm-08-a.html)

Creeks_Ridges 09-16-2003 06:50 AM

Sighting In 7mm-08
 
Need help on best way to sight in your rifle. I have read many articles on what the best way is to do this. So I decided to sight in at 25 yds dead on and take it from there. I shoot a Tikka T3 7mm-08, 139 grain Interbond bullet with 49.9 grains of H414 powder suppose to be shooting around 2900 fps.

Its dead on at 25 yds 3 shots in a small black dot, but when I moved it out to take a 200 yd shot, which its suppose to be dead on at 235 yds according to the Percentage tag for my rifle it shot 12 inches high.

Now what I am wondering is this, should I sight it in at 3 inches high at 100 or just keep adjusting with the way I have it now dead on at 25yds and go from there.

Any advise or suggestions would be greatly appreciated...

Thanks for your help!
Creeks_Ridges

WV Hunter 09-16-2003 06:59 AM

RE: Sighting In 7mm-08
 
Did you go from 25 to 200? If so, that' s probably your problem. I typically start around 25 then back up to 50 then to 100...and so on. I wouldn' t worry too much about where it' s " supposed " to shoot...find out where it " does" shoot, and go from there. :)

frizzellr 09-16-2003 07:35 AM

RE: Sighting In 7mm-08
 

I wouldn' t worry too much about where it' s " supposed " to shoot...find out where it " does" shoot, and go from there.
Very good advice. The only way to know where your gun shoots at a given distance is to fire it at that distance. Tables and charts may be close but there are alot of variables in each individual rifle, not to mention factory ammo charts fudge numbers in their favor.

PaJack 09-16-2003 07:59 AM

RE: Sighting In 7mm-08
 
I would shoot the gun at the distance you want it sighted in for! Like the other gent' s said,the charts are just a refrence...;)

noway 09-16-2003 09:06 AM

RE: Sighting In 7mm-08
 
Normally if you are dead on at 25 yards you will be roughly 3" high at 100 yards.

How many shots did you use to confirm your zero dead on at 25 yards.

Like the other posters said go to the range you wanted to be sighted in at and sight in for that yardage. Then back up and shoot at 100 to see where you are sighted so you can double check you sight in later at 100 yards if you need to.

Creeks_Ridges 09-16-2003 12:21 PM

RE: Sighting In 7mm-08
 
Yeah I went from 25 out to 200yds.... I just didn' t think it would shoot that high out at 200 yds, kinda was hoping it was in the black, which was about a 6 inch circle.

Guess I will just have to do like the one guy was saying 25,50,100...etc...to see where the rifle is going to shoot.

I want to be able to hold on the shoulder of a deer say out to 300yds without guessing if I am going to have to hold high or not. Cost me a nice buck last year and I don' t wont to repeat that again.... If you know what I mean, still not over it!

Thanks!
Creeks_Ridges

akbound 09-16-2003 02:19 PM

RE: Sighting In 7mm-08
 
I would be certain to zero the rifle at 100 yds. (Depending on what you are expecting for a " hunting Point Blank Range (PBR)" the range at which you want your bullet to travel no more than 3" to 5" above or below your point of aim.) With a load that you quoted your final zero will probably end up being in the vicinity of 2.5" high at 100 yards. Which will most probably put you within that 6" to 8" circle out to the maximum range of your PBR. But like the others have already said, " shoot at those ranges to confirm it" .

I also shoot my rifles first at 25 yards when I start zeroing. I generally want the strike of my round to be close at 25...then I move to 100 for a " zero" . Depending if I am sighting in open sights, aperature sights, and or telescopic sights, determines where I would like my rounds to impact at 25 yards. More importantly, " how high above the line of the bore is the line of sight?" You didn' t say what type of sights you were using, or how high above the bore line your sights are. What I am inclined to believe is that you are probably using a telescopic sight, (and with a difference of zero at 25 yards and a foot high at 200 yards), I would suspect it might be a scope with 40mm or bigger objective and set in either medium or high rings. (Or even a somewhat smaller or larger objective lens but still set in higher rings.) If this is the case....your line of sight would be relatively high above the bore line. Which, when zeroed at 25 yards, requires that the axis of the bore line in relationship to the sight line is tilted quite high. Think of two lines, parallel to each other. In order to bring these two together at 25 yards requires that you significantly tilt the bore line " tilting it up" in relationship to the line of sight. Which would explain why the strike of the round is so high at 200 yards in relationship to the point of aim.

Suffice it to say when zeroing a scoped rifle at 25 yards I usually try to get the bullets to impact centered for windage and 3" or 4" low at 25 yards. Then when I move to 100 yard range I find the zero closer to " my zero" . Depending on cartridge and sight configuration I will zero my rifle either " dead on" (in the case of a pistol caliber carbine or dangerous game rifle), to as much as 2" to 3" high at 100 yards. But even then if you have access to a longer range confirm your bullet strike at 200 and even 300 yards (or more) if you intend to actually shoot at those ranges.

From the moment your bullet leaves the bore it starts to drop. We compensate for this by slightly tilting the axis of the bore up when we zero. This causes the flight of the bullet which actually starts under the line of sight to cross above the line of sight at a nearer range it continues to climb until it reaches its zenith, (or apex), and then falls back below the line of sight. Meaning it intersect the line of sight again somewhere downrange. Depending on the ballistics of your cartridge, (and all the external ballistics), and your sighting equipment determines how best to sight it. Most people make it simple by sighting their scoped, modern rifles, to strike between 2" to 3" high at 100 yards which usually gives them a " hunting zero" to something between 200 to 300 yards without too much concern about shooting over or under deer sized game. Suffice it to say it is both as " simple" or as " complicated" as you' d like to make it. (Keep it simple.....if you can!)

Creeks_Ridges 09-16-2003 09:25 PM

RE: Sighting In 7mm-08
 
Nice reply akbound, I think I am going to try it at 100yds and just see what happens. I do have a 40mm objective. Its a 4.5 x 14 x 40 Leoupold. But do not have see through scope mounts. I have it right near the barrel.

Most of the shots that I get around here would be 100 yds or less in the woods where I hunt, but they are many fields around in the area that I am hunting, and last year I shot a 8 pointer on opening day, and on the next days hunt a bigger buck was chasing a doe through an open field and gave me what I would say around a 275 to 300 yd shot dead still in the field.

Guess what?....thats right>>>>>>>>>>I missed! And I want to be sure this year that doesn' t happen again, if you know what I mean...

Thanks for your help!
Creeks...

I hunt in Virginia.

thndrchiken 09-16-2003 10:09 PM

RE: Sighting In 7mm-08
 
Well not to beat the dead horse hear, but the only way is to actually practice at those ranges. Zero the rifle for 100 yds. Then actually practice at 200 yds to see where your going. Sounds like a nice rig.

handloader1 09-16-2003 10:17 PM

RE: Sighting In 7mm-08
 
With the information given:

3.3" high @ 100 yds.

4.0" high @ 159 yds.

3.4" high @ 200 yds.

-2.0" low @ 300 yds.

-4.0" low @ 322 yds.

Maxium Point Blank Range (MPBR) on deer is 4.0"

Remember these trajectory figures are estimates; actuall figures may vary.

Good luck.




All times are GMT -8. The time now is 01:09 PM.


Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.