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View Full Version : Tried this in the optics forum eotech question


AzNfree
09-04-2008, 10:50 AM
Ok,
maybe the AR guys can help me out on this as i don't seem to be getting any help from the optics thread. I have a 512 zeroed at 50yds and was wondering what kind of impact changes i should be seeing at 25yds, 100yds and 200yds. anyone have an idea? i have it mounted on a stag-15 flat top.

JBird33
09-04-2008, 11:03 AM
Zeroed at 50 with standard 55 gr rounds is 1" high at 100 and zero again at 200 yards, I think.

Paratus et Vigilans
09-04-2008, 11:10 AM
It depends on your barrel length and the ammo, mostly, as well as temperature and other environmental factors as the distance to the target increases.

Standard 55gr. FMJ fired from a 16" barrel with a 50 yard zero on your sights (iron or holographic) will usually hit about 1.25" below POA at 25 yards, right at the POA at 50 yards, a smidge over an inch high of the POA at 100 yards, and right at the POA again at 200 yards. That's known as the Improved Battlesight Zero (IBZ), which is based on the 50/200 yard cross-over point of the 55gr FMJ round. If you're shooting something heavier or lighter or your barrel is longer or shorter than 16", it's going to be slightly different. Get a ballistics chart for your barrel length and choice of ammo to give you an idea of where it should go, and then go out to a KD range and actually shoot it to see where it really does go.

AzNfree
09-04-2008, 12:58 PM
Wow thanks, that clears it all up! i was surprised that i was low at 25yds and high at 100. i thought it was me.

Mississippi
09-04-2008, 1:11 PM
Combat zero is at 25 yards not 50. You will be pretty good out to 200 yards if you zero at 25/30.

aplinker
09-04-2008, 1:25 PM
Combat zero is at 25 yards not 50. You will be pretty good out to 200 yards if you zero at 25/30.

25/300 is the old method.

Current is 50/200 (improved battle zero)

Ravenslair
09-04-2008, 4:24 PM
I am zeroed at 25 yds. At 50 yds, POI is about 2" above POA. At 100 yds, POI is about 4.5" above POA. I am zeroed using 55gr Ranger softpoints. Have not shot out past 100 yds yet. Still need to get my sheet finished past 100 yds.

cmace22
09-04-2008, 5:19 PM
25/300 is the old method.

Current is 50/200 (improved battle zero)


+1 IBZ