Sighting in

[Fishinfred]

I am considering building either a AR-15 IN .458 SOCOM OR a AR-10 IN .308 with either of these weapons the primary use will be for feral hog hunting and honestly don't expect to have a shot over 100 yrds and probably most will be in the 50-75 yd range

At what distance should i sight my rifle in at for The flatest possible trajectory from 0 to 100 yds?

 

[clearcut]

Welcome to THR With 150 grn bullet a 25 yd 0 should give you + 1" @ 100 yds. Thats just speculation you will just have to try it on the range.
CC

 

[Nature Boy]

I'd zero at 100. You'll hit the vitals of any hog shy of a piglet between 0 and 200-ish yards.

 

[Corn-Picker]

The answer will depend on the vertical distance between the center of your bore and the center of your scope tube, which you will not know until you have your scope installed on your rifle. I'd site it in to be 1.5" high at 100 yards and not worry about it too much. If you're shooting squirrels and doves with a pellet gun it's worth worrying about such things, but not in your case.

 

[Sunray]

You may want to re-think a .458 SOCOM. Ammo starts at $63.99 per 20.
Sight in at 100. Even if you think you'll never shoot farther, you'll still be fine for deer and Porky. http://guide.sportsmansguide.com/ballistic-chart/remington_charts/308wibal.htm

 

[Reloadron]

I am in the sight in at 100 yards group. You get a good zero at 100 yards and rest assured your pig or any deer sized game should be dead. I would also be thinking 308 Winchester. The 458 SOCOM as Sunray points out is expensive and for hunting hogs I really do not see the merit of the 458 SOCOM over a traditional 308 Winchester.

Ron

 

[Jesse H]

Disregard...failed to notice OP was asking about 308.

 

[Dr T]

Suggestion: Go to the Hornady website and play with the ballistic calculator. The trajectory will depend primarily on the bullet ballistic coefficient (b.c.) and the muzzle velocity (mv).

Don't make the mistake of sighting it in for too short a distance. Shooting distances can be deceptive in the field.

 

[No4Mk1*]

A 100 yard zero for a hunting 308 is the worst possible choice in my opinion. That is the zero range which the bullet never rises above point of aim. A longer zero, even 150 yards, only elevates the bullet 0.6" above point of aim between 110-110 yds. This is beneficial because it also slightly brings the bullet up at extremely close range (<30yds), and allows shooting to 200 yards without range estimation being just 2" low at 200 yards. There is very little reason not to zero all the way at 200 (1.6" high at 100) as you are still within 2" all the way to 235 yards.

As a compromise i suggest you consider 170 yards (1" high at 100) That only allows the bullet to be 1" high from 90-130 yds, and not 2" low until 210 yds. In so doing it will bring the bullet up to point of aim better inside 30 yds.

See for yourself with a ballistic calculator.
For the above i used 150gr bullet at 2820fps .415bc sight 2" over bore.

 

[The Big D]

I would agree that being slightly high (between .5" and 1.5") at 100y will serve you well. A simple way to achieve that would simply be to zero at 50-75.