.308 ballistic question

[Filip]

So I remember way back when I was a young private on the rifle team being advised to aim at the chin of a fig.11 at a certain distance…can’t recall the distance, may have been 400m. I guess this makes sense considering 5.56. So my question is how this all relates to say a heavier 150 grain .308? At what distance would one have to change point of aim if using an optic without fancy features?

Cheers!

 

[7mmlefty]

Good question and the answer is... A 150 grain bullet traveling at 2750 fps bulls eyed at 200 is going to drop about 10 inches at 300, and a dramatic 30 inches at 400 yds. mostly the same for all rifles in that class.

 

[Filip]

Thank you for this important information...I'll keep this in mind next time I'm out at the range.

 

[Ganderite]

This all depends on where the rifle is zeroed and how high the scope is above the bore.

In the case of the AR-15 class rifle, the scope is much higher above bore than on a 308 bolt gun.

My AR-15 is zeroed to hit point of aim at 300.

At 100 and 200 I aim a bit low - about 6" low.

At 400 I aim at brim of helmet.

At 500 I aim at top edge of paper.

A 308 bolt gun with a low mounted scope would probably have to be aimed a bit higher at 400 and 500.