what zero at 100yds under these scenarios

dantheman

This deer season i will be hunting in woods and open fields. My shots will potentially range from 10yds to 300 yds. where should i sight in my .308 at 100yds to cover both these scenarios. I will be shooting either 150gr or 165 gr ammo. Thanks

Win mag

I have a 300 Win-mag with a Leupold Variax 111 2.5 x 7 or 8 and have been confident with sighting in at ~ 1.5 to 2 in high. In all my cases of stationary 50 yard to 175 yard shots, I have aimed dead on and been sucessful.

bambihunter

I don't recall what it's called, but there's a theory that basically involves the bullets trajectory going so far above the bore, and so far below. Most guns would need to be sighted in at some odd distance (it seems like my .300 mag was supposed to be dead-on at 312 yards) to obtain this setting. Essentially, it is that you can shoot from 0 to xxx yards with no hold over/under.

Personally, I'd just sight it at 100 and then add elevation for longer shots. If you regularly shoot longer shots, then I'd zero for your normal ranges.

scsims

Point Blank Range.

bambihunter

scsims, if you sight a gun with a scope at point blank range the scope will be kiltered something fierce. If the centerline of the scope is 2" above the centerline of the bore then then just think about how crooked that'd make it.
If I'm not mistaken if you zero a .308 at 100 yards then the bullet is actually still rising but should start back down shortly. If you zero at point blank range the bullet will likely keep rising for 300+ yards because of the angle of the scope.
If we're talking open sights, that's a little different since they are much lower to the bore, but I'd say set them between 25 and 50 yards.

Laredo Lefty

Since you are shooting a .308 rather than a 300 mag your bullets are going to be traveling around 2800 fps + or - a little. Several hundred fps slower than a 300 win mag.

If you are using 150 grain bullets they will have a ballistic coefficient of approx .38 to .42. using an average of .40, a 150 gr bullet zeroed at 100 yds will drop 3.8" at 200 yds and 13.9" at 300 yds.

I would zero it at 200 yds. Then it would be 1.9" high at 100 yds and only drop 8.2' at the 300 yd mark.

scsims

bambihunter, I'm refering to a function that my ballistics software has, You input the height in inches of the kill zone and it calculates the point blank range.

Tailgunner1954

308Win point blank range with:
Federal Prem. 150gr Nosler BT +2.7 high at 100yd = +3"@ 133yd, -3"@277yd*
Rem. 150 PSP +2.73@100 = +3"@ 130yd, -3"@ 267yd*

*Factory spec.s, your results will vary, usually to the shorter side.

Now, if you had practiced at ranges over 100yd (you have practiced at 100 haven't you?) you would already know these numbers for your rifle. As you don't know, I'm assuming you haven't practiced and should NOT be shooting at any game that is further away than you have practiced. *This from a guy that does practice to 500yd and shoots game out to 400yd*

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Some guys like a mag full of lead, I still prefer one round to the head.

cowdoc

dan the man here is a site that i use for ballistics
you can enter in all the imputs then will calculate bullet drop for you
you need to know fps,bc,bullet weight ect
by the way i zero my rifle at one hundred yds then go from there

http://www.eskimo.com/~jbm/ballistics/ballistics.html

hope that helps you
doc

bambihunter

scsims, sorry I guess I didn't get what ya meant. I don't think that was the term they used but sounds like the same thing.
I apologize if I sounded like (or was) belittling your answer, it was my misunderstanding... [V]

OleDuk

dan, all good advice above. My two cents worth is to zero that rifle to hit 3 inches high at 100 yds. and you won't have to worry about trajectory until you start taking shots past 300 on deer.
This method is referred to as "Maximum Point Blank Range" and is recommended by some notable shooters, not the least of whom is the late Warren Page. I don't recall if Page called it that exactly, but he recommended the method. If the critter is past 300 yds, and you're confident of your ability to make the shot, hold the horizontal crosshair even with the top of his back in the chest cavity area and you'll be taking home some venison.
Good hunting,
OleDuk

shoey

After reading this, and comparing my situation, I just had a question. Last post said 3" high at 100, which sounds very reasonable...however, how high is this at 50? Just wondering, cause most of my hunting is in the thicker stuff, but sometimes in the open. Dont shoot a .308, but its one of my choice cartridges when I do buy a deer rifle...

shoey

Tailgunner1954

3" high at 100 will put you about 1 3/8" high at 50yd, 3 3/8 high at 136yd, 2 1/8 high at 200yd, 5/8 low at 250yd and 4 3/4 low at 300.

Yardages are baised on factory specs, you rifle is different, so results will vary.

This methiod isn't a "hit exactly where you hold" system, but a "hold in the middle and take the shot" system.

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Some guys like a mag full of lead, I still prefer one round to the head.

allen griggs

The three inch high hold at 100 is good. That is what I use.
It would be good to practice at 300 yards, no doubt, but maybe his range only goes to 100.
I have never had a chance to go to a range that went past 100, but the one long shot I got, at 194 yards I got the deer right through the heart.
I had practiced a lot at 100 and I knew my ballistics

uhoh

best just forget about deer beyond 300 yds, if all you have is a 308. And in any case,forget them unless you have a lot of experience at such shooting, and a rock solid firing position, a rangefinding scope, and the deer is bedded down. You have no control whatsoever on whether or not the deer takes a step. The bullet will take at least .3 second to cover 1000 ft,and it is rather easy for any deer to take a step in .5 second. .5 of a step can mean a chest shot hits the guts. As Jeff Cooper says:You should APOLOGIZE for your long shots." They mean that you are too lazy and/or inept to get closer, and too irresponsible to care if you lose a crippled animal.

JustC

my 7mag with a 150gr NBT I am ~4" high at 100yds and pretty dead on at 350yds. With a 150gr pill over a 308 powder charge,..I would 5" high at 100yds and hold under for close range shots.

My first suggestion would of course be to buy a set of target knobs like stoney points or even a factory set,..and dial in your "come-ups"

why chase the game when the bullet can get em from here?....
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