Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Point of Impact - 50 to 100 yards
#1
If I zeroed a scope at 50 yards (load 120 gr bullet and 31.3 CFE 223), would the point of impact at 100 yards be higher or lower and by roughly how much?
Reply
#2
Calculators show that a 50 yd zero is pretty much spot on at 100 yds (assuming 2500 fps muzzle velocity).
Reply
#3
Assuming 2500fps/120AMax, scope height 2.5" above bore and a 50yd zero your round will impact 1" high at 100yds.
(ref; JBM Ballistics, online)
Reply
#4
Good point. I left the scope height at the default 1.5".
Reply
#5
You need to know:

* Optic height above bore
* Projectile weight
* Muzzle velocity
* BC
* Temperature
* Barometric pressure

When I zero at 6600ft elevation, then come down to 4400ft, the POI shift is pretty big. I just did that this past week, and the zero stop would't let me go low enough to compensate for the low POI at 4400ft.

50yd zeros normally print high at 100yds though, with your scope height and mv being the biggest factors in how high.
NRA Basic, Pistol, Rifle, Shotgun, RSO

CCW, CQM, DM, Long Range Rifle Instructor

6.5 Grendel Reloading Handbooks & chamber brushes can be found here:

www.AR15buildbox.com
Reply
#6
Is the scope height measurement the distance from the center of the scope to the center of the bore?
Reply
#7
lwminton Wrote:Is the scope height measurement the distance from the center of the scope to the center of the bore?

Yes. I use calipers.
NRA Basic, Pistol, Rifle, Shotgun, RSO

CCW, CQM, DM, Long Range Rifle Instructor

6.5 Grendel Reloading Handbooks & chamber brushes can be found here:

www.AR15buildbox.com
Reply
#8
Thanks all.
Reply


Forum Jump:


Users browsing this thread: 1 Guest(s)