Boresighting question

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AJG

New member
I just mounted my Bushnell on a set of Burris Tactical rings & bases on my Savage 308.
Now, I know its not exact, but I want to boresight the rifle before going to the range. I dont have a laser and I really dont want one, so I'll be looking thru the barrel to get them pointed in the same general area enough to at least get it on paper @ 25yds.

Question is, how far away do I place the target doing it the "old fashioned method"?
 
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Smokey Joe

New member
Boresighting...

AJG--I'd just take the rifle to the range, sandbag it to a bench, and boresight it @ 25 yd. if that's the distance you want. Then you can check yr results immediately. If boresighting at home, any closer, the parallax problem becomes nearly insurmountable.

Take yr tool kit along, so you can handle any necessary adjustments.
 
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mapsjanhere

New member
Measure the distance between barrel axis and center of the scope. As long as the barrel sight aiming that distance above the target you see through the barrel the distance doesn't matter.
Alternatively, I had good luck aiming at street lights at night far enough so the 1" or so didn't matter.
 
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ZeroJunk

New member
I usually put the rifle in gun vise on a table and bore sight it on a tennis ball at the other end of my basement, putting the crosshairs and the center of the bore on the ball. That will get me on a 2 foot square target at 100 yards and I work from there.
 
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AJG

New member
Smokey, Zero & Maps... thanks.

Smokey's makes great sense... but I dont wanna waste range time doing it there,,,, wanna at least get it in the ball park before I get there.

Zero, how far away is the tennis ball?

Mapsjanhere... streetlight good idea...

SO I guess as long as its not upcloseandpersonal distance... anything 20 yards and out is kosher.
 
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thesheepdog

New member
25 yards you should be zeroed at 250 yards-pretty close.

Mount the rifle on a solid location and zero the bore with the crosshairs at 25.
If you're at 100 yards, put the cross-hairs 3 inches above the point of aim (POA) and you'll be zeroed at 250.
250 yards is a good range to be zeroed at for a standard rifle.

Otherwise just zero at 100 yards and call it good.
 
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AJG

New member
Well, I dont nessessarrily agree with the 250 yard zero, but I do believe that its a personal preference deal. I think zero should be what distance you normally shoot at. 100, 200, 300 whatever it may be. And thats another discussion topic.... but thanks for the boresighting distance... 25 yards it will be....
 
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thesheepdog

New member
What bullet weight are you using and I can run ballistics on my software real quick and see what would be the best range to zero it at.

What max range do you want your rifle zeroed?
 
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AJG

New member
Winchester Ballistic Silver Tips...
150grn
2810 fps.

ballistics I have:
rng drop(in) drop(moa)
100 = 0 0
200 = -3.6 -1.7
300 = -13.3 -4.2
400 = -30.1 -7.2
 
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thesheepdog

New member
If you zero at 25 yards, you'll be zeroed at 237 yards-with your current load.
Change the zero to 100 yards and you'll have to compensate for anything past 147 yards.
At 100 yards, the bullet is already dropping and losing velocity. At 25 yards, you're over compensating since the bullet doesn't drop much at all, and due to the sight height, you're gaining some MOA.
 
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AJG

New member
I really think thats an entirely different topic.
I really do appreciate the info, but if a hunters average shot is 100 yards then thats what they should zero for... ie same it it is 25yds or 200yds... but thats what should be used. And having a good dope sheet to compensate on anything under or over.
But''''''''''''''''
I just wanted to know what range I should have the target at when I "boresight" my rifle so I can just get it on paper the first time I get to the range.
Thanks for the "best zero" info though... I cant figure out how you figured that out... but its good info to know
 
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AJG

New member
disagree

""If you zero at 25 yards, you'll be zeroed at 237 yards-with your current load.
Change the zero to 100 yards and you'll have to compensate for anything past 147 yards.
At 100 yards, the bullet is already dropping and losing velocity. At 25 yards, you're over compensating since the bullet doesn't drop much at all, and due to the sight height, you're gaining some MOA. ""

I disagree a bit with your statement about having to compensate on anything over 147 yards if I zero at 100.
At 150 yards with a 100 yard zero a 150grn 2810fps bullet will drop approximately 1.1 inches. If I'm shooting at a dear with a 4 inch kill zone I dont have to compensate until the range is 170, because the drop is 1.9 inches. SO theoretically.... no compensation is needed but we all know there will be some.

What ballistics program do you use?
 
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thesheepdog

New member
I really think thats an entirely different topic.
I really do appreciate the info, but if a hunters average shot is 100 yards then thats what they should zero for
Click to expand...
...
My shots are never under a 100. I can't get that close.
If you zero at 25, then you'll be about 2.5-3" high at 100 yards. Which is very easy to compesate for, just aim lower.

ie same it it is 25yds or 200yds... but thats what should be used. And having a good dope sheet to compensate on anything under or over.
Click to expand...
Yeah but you really don't need a dope sheet for hunting. Just guestimate since you shot will only be about 2-3 MOA high @ 100 yards.
But''''''''''''''''
I just wanted to know what range I should have the target at when I "boresight" my rifle so I can just get it on paper the first time I get to the range.
Click to expand...

25 yards is what a lot guys do (so they can get a good range of little to no compensation-depending on caliber). Some choose to do 100 (some ballistic reticles require a zero at 100)

Thanks for the "best zero" info though... I cant figure out how you figured that out... but its good info to know
Click to expand...

I have ballistics software on my Iphone :cool:
I am fixing to use it heavily on my 6.5 loads.
 
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thesheepdog

New member
Here's a more simple program for ballistics.

http://www.hornady.com/ballistics-resource/ballistics-calculator

I disagree a bit with your statement about having to compensate on anything over 147 yards if I zero at 100.
At 150 yards with a 100 yard zero a 150grn 2810fps bullet will drop approximately 1.1 inches. If I'm shooting at a dear with a 4 inch kill zone I dont have to compensate until the range is 170, because the drop is 1.9 inches. SO theoretically.... no compensation is needed but we all know there will be some.

What ballistics program do you use?
Click to expand...

Well relatively speaking, I would rather shoot low than shoot high. That way when you get to your zero, you don't have to compensate. And if you shoot past your zero, you won't have compensate AS MUCH, as if you zeroed at 100. It's just less adjustments and such, which can be a pain to keep track of, if you're not using a ballistics reticle.

But yes, you're correct, if you change your load, you will have about a 1.5 inch variation at your zero range (237 yards)

I use Ballistic:Field Tactical Edition for the Iphone.

Sorry if i confused you regarding my statements on compensation. I am a hunter and a target shooter, but I like my round to be exactly where i intend for it to be (within .5-1.5 MOA)
As far as hunting or self-defense is concerned, you should be fine with a 100 yard zero out to 200 yards.
 
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AJG

New member
your absolutely correct... don't need a dope sheet for hunting.
if I zero for 150 then out to 200 I'm still within a 2.1 inch group.
That to me... is aim dead in the center anywhere 0 to 200 and your good to go. Its not supposed to be rocket science... its hunting... supposed to be fun. just like camo... do you really need it?
Whatever happened to the old days? shoot it and figure it out as it happens? lol
 
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