basic scope elevation to start long range

[bruchi]

As soon as I get a pair of rings I get my long range AR set, this is a 223 rifle, 24" 1:8 barrel, idea is to shoot it at 300 and 600 yards with Hornady Match 77 grain ammo.

Never shot a 223 at this distance so I am at a loss regarding a starting point to set the scope dials regarding elevation, I will get them zero at 100 yards beforehand but need a place from there to start at 300 and then at 600 yards.

Any input here will be greatly appreciated, I know it is ultimately a matter of trial and error but ammo is pricey this days so any way to make this more affordable helps!

[a1fabweld]

Do you have access to a Chrony? If so measure your velocity & download some ballistic software to map out your dial-ups.

[shootist~]

JMB Ballistics is a very good free online ballistic software. You can get the BC for the 77 SMK from their pulldown menu. You need your muzzle velocity and your unadjusted station pressure (or reasonable estimates). The other inputs (humidity, temperature, and sight height) are also needed, but are less important.

You can run your data in Mils or MOA and you will learn quite a bit just by getting it set up.

http://www.jbmballistics.com/cgi-bin/jbmtraj_simp-5.1.cgi

[Georgie Boy]

I'm hitting 2750fps through a 24in bbl using Hornady 75gr match. May not be exact with yours but you can use it as a good reference to get you started. As stated before, a chrono and a good ballistics calculator would do well for you. I've been using Shooter on a Droid for a few months now and if you've got an Android phone, it's worth the $10.

[Lawrence]

I like working from a 200 yd. zero
From 100 to 200, about 2. minutes
From 200 to 300, about 2 - 3 minutes
From 200 to 600, about 12 - 13 minutes
Light, wind, & shot angle effect your zero's & so does your set up, so every rifle is close, but not exact. Shoot it some & have fun !