300 BO zero at 15 yds

[Brazman]

Scenario - you have a hunt lined up in two weeks for opening day. You want to zero your 16” 300 BO shooting supers, but the only place you can go is a range with 15 yd lanes. How high would you want/need to sight in at 15 yds to have point blank range accuracy between 70-120 yards?

I know it’s not ideal. I’m thinking 2” high at 15 yds, but I’d like other opinions. Thanks in advance.

[npe001]

Close as I could find on a quick google search...

https://300blk.wordpress.com/2013/12/05/update-my-new-approach-to-300-blk-zero/

[Ag 96]

You need to sight it in lower than the target at 15 yards if you’re going to hit anything much beyond 30 yards. Probably whatever your center of bore to center of reticle height is minus 1/4”… but I wouldn’t trust sighting it in like that for any hi ting situation. I’d find a longer range.

[Gunnyart]

I'd be zero at 15 if not an inch low depending on how high your optic sits above the bore line.

[howabouttheiris]

You need to sight it in lower than the target at 15

Agree.

You want to be low by ~85% of your scope height over bore.


Assume a straight line of bullet travel.
If your scope is 2" high.
At bang, the bullet is 2" low.
At 100yds, you want the bullet to be 0" low.
By 15 yards you have only progressed 15% of that distance, so you are still ~1 3/4" low.

[Raider4044]

300 BO zero at 15 yds

Deleted

[Twist]

Close as I could find on a quick google search...

https://300blk.wordpress.com/2013/12...-300-blk-zero/

That graphic matches why came to my mind when I opened this. Granted, I haven’t shot at 15 yards but it would seem to me that “lob” would come into play a bit and you’d need to be either in at that distance or slightly low.

I know when I mess around at 50 with my suppressed SBR, I’m a little high when using my scope dialed in at 100 without making adjustments.

[El Paisano]

Scope height above bore makes a ton of difference.

[jaime1982]

I got nothing but borrow someones else's rifle.

[Raider4044]

300 BO zero at 15 yds

Definitely not ideal IMO. Plugging in a 110 Barnes TTXS at 2200fps sighted in at 15 yards on Geoballistics, you’ll be 5 MOA/1.45 mils high at 100 yards, so you’ll need to sight in 5 MOA/1.45 mils low at 15yds due to the arc of the bullet. Scope mounting height changes it quite a bit at that distance. I think I left it at 1.5” height for that data, will be higher on an AR.

[Brazman]

Thank you for your input. If I can get my shots to group about 1.5” low with no left or right travel, I should be in minute of vitals at 100 yds, shouldn’t I? I’m not planning on taking any neck shots or anything.

[Gunnyart]

Thank you for your input. If I can get my shots to group about 1.5” low with no left or right travel, I should be in minute of vitals at 100 yds, shouldn’t I? I’m not planning on taking any neck shots or anything.

You’ll be good to go

[GarGuy]

Find a place to shoot the gun at 100yd. Period

[softpoint]

While it can be done, in theory, even slight differences in point of impact at 15 yards will make significant differences at 100 yards. You need to know exactly how high your line of sight is over your bore to make a reasonable calculation. AR style rifles are some of the worst culprits because of the high line of sight over the bore. Sighting that way is better than nothing, but I'd try to find a place I could shoot farther...

[freerhunter16]

Find a place to shoot the gun at 100yd. Period

This. Or take a different rifle.