80 yard sight-in

[flip1]

With the average 30 cal hunting rifle, where should I be sighted at 80 yards to accomplish 2" high at 100 (and in theory 0 at 200).

My range has terrible ports on the 100 yard, and with my height I can't shoot worth a damn. So I typically start off 1.5" low on the 25, and just test on the 100. Usually I'm pretty close to 2" high, but it is really hard to be consistent.

I was thinking that the 80 yard is wide open, so I could do some more shooting there. Would say 1" high typically be about right at 80 yards with a .308, 300, 30.06?

 

[martinbns]

Terrible Ports?

I would think that the two inch high thing at 100 would be very close at 80.

 

[a j cave]

+ 1 1/2 or 1 3/4 at 80 should be close.

 

[zimbu]

That's a big average... 30 cal

 

[X-fan]

1.5" high at 80 yards will give you a 200yd zero...This is what I would do as the trajectory stays within 2" of line of sight all the way out to almost 250 yards.

2.0 inches high at 80yds will zero you a 225 yards, but will result in the trajectory being 2.5" high from 100-150 yds....not a big deal if you are hunting moose.

 

[stubblejumper]

It depends on the muzzle velocity,ballistic co-efficient,and the height of the center of the crosshairs above the bore.

 

[John Y Cannuck]

The only way to be sure of a 200 yard zero, is to actually shoot it at 200 yards.
You can play with balistic tables all you like, they won't tell you the truth about what your particular load/bullet/primer/bullet/rifle are really doing, until you really shoot it.
If your range can't accommodate that, see if you can get legal access to a gravel pit for an afternoon, or a farmers field with a good backstop.

 

[sbtennex]

The only way to be sure of a 200 yard zero, is to actually shoot it at 200 yards.
You can play with balistic tables all you like, they won't tell you the truth about what your particular load/bullet/primer/bullet/rifle are really doing, until you really shoot it.
If your range can't accommodate that, see if you can get legal access to a gravel pit for an afternoon, or a farmers field with a good backstop.

X2. 100 yard groups don't translate all the time to 2,3,4,600 whatever yard projected ones. Only way to know is to shoot at actual ranges. Some will surprise you i.e. a 2" 200 yard group CAN be a 2" 300 or 400 yard group. It can also be an 8" 400 yarder. Lot of things can determine it and as stated, only shooting at hunting ranges can be the the proof.

 

[X-fan]

I agree with actually zeroing the rifle at 200yds.
As mentioned many rifle/load combinations tend to fall apart at 200 yards.

Though I wouldn't stretch it much farther, give me a rifle that shoot s close to MOA with the 80 yard zero mentioned and I will guarantee dead animals at 200 yards.

Muzzle velocity has very little to do with short range trajectory. I ran the same 180 grain .308 bullet from 2800-3100fps and the POI changed by less than one inch at 200 yards with the identical 80 yard zero....

Better than most rifles and shooters can manage in the field.

 

[KDX]

I agree with actually zeroing the rifle at 200yds.
As mentioned many rifle/load combinations tend to fall apart at 200 yards.

Though I wouldn't stretch it much farther, give me a rifle that shoot s close to MOA with the 80 yard zero mentioned and I will guarantee dead animals at 200 yards.

Muzzle velocity has very little to do with short range trajectory. I ran the same 180 grain .308 bullet from 2800-3100fps and the POI changed by less than one inch at 200 yards with the identical 80 yard zero....

Better than most rifles and shooters can manage in the field.