Ask Foghorn: Zero Distance for 300 AAC Blackout?

P1070145

Seth writes:

What are you using for zero distance for your blackout? I am big fan of the 50/200 zero in .223/5.56 and I am hoping there is something similar for the blackout round. I did a little experimenting on trajectory software, but didn’t come up with anything concrete.

The good news is that the old 50 yard zero works pretty well for 300 BLK as well. Here’s why . . .

300 AAC Blackout is a fantastic hunting round. So long as your target isn’t much over 100 yards, that is. While having a chunky projectile is a nice improvement over the standard 5.56 cartridge, it does mean that you lose some muzzle velocity. And in turn, the trajectory past 100 yards for this gun has been described as “rainbow-like.”

However, over that 100 yards the trajectory is remarkably consistent. With a scope height of 1.5 inches, the parabolic arc of the round peaks at 50 yards and returns once more to -1.5 inches at 100 yards. Or, in terms of hunting, a variation of less than the profile of a deer heart over 100 yards.

In my opinion, the 300 BLK round is the perfect gun for game under 100 yards away. Or, in other words, just about anything in South Texas (where I live). But when you start moving past 100 yards, its time to break out the zippier calibers. At 150, the round has dropped 6 and a half inches. At 200 its almost a foot and a half down.

I’m not saying that it can’t be done. I’m regularly singing steel at 250 with my 300 BLK rifle, with a nice +3.4 Mil hold. But that’s not a shot I would be comfortable making on wildlife. Not humane.

And that’s why I like the 50 yard zero. It keeps the trajectory nice and flat for the distance that I’m comfortable killing things, but once you reach the end of that 100 yards its like the thing falls off a damned cliff. You could get a little more distance out of a 25 yard zero (under 1.5 inch drop at 150 yards), but then the bullet moves through a little over 3 inches of variation over 100 yards compared to 1.5 inches with the 50 yard zero.

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