Offset red dot zero.

[jaxman7]

Those who use one, what is your zero distance?

At the range today and sighting in a 1:30 offset 3.25 MOA Insight MRDS. 14.7" BCM barrel using American Eagle 55g 5.56. It is mounted on a Unity Tactical offset mount. I'll talk more on the mount later but I like it a lot so far.


Decided to run a 25 yard zero.

Now with this being my first time messing with offset zeros it honestly through me for a loop. First sight in was at 12 yards. Just to get it on paper. Set it at that distance at roughly 2 inches high then backed up to 25 to finalize the zero.....The round wouldn't even land on a 12"x16" target. Weird.

Got it dialed in at 25 and then shot at 10 feet and then 50 yards to get an idea of where the bullet will land at those distances. Up close it was 2" low. At 50 the rounds were 2 3/4 inches high.

Would like to hear some opinions on where off set users zero their red dot or irons. Thanks,

-Jax

[markm]

Got it dialed in at 25 and then shot at 10 feet and then 50 yards to get an idea of where the bullet will land at those distances. Up close it was 2" low. At 50 the rounds were 2 3/4 inches high.

If you're most likely distances trend near 25 you're set.

I'd personally opt for a 50 yard zero and know to hold over for close up shots.

[Moltke]

Why not a standard distance? 50y/m? 100y/m?

What optic are you using on top of your rifle as a primary?

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I zero at 100 yards. Optics/Irons, everything starts at 100 for me and I holdover as needed.

http://m4carbine.net/showthread.php?t=107572

[SkipD]

I agree that a 50-yard zero makes the most sense for an AR with a combat sight. That will put the bullet within +/- 2.6 inches (vertically) of where the sight is pointed on the target from the muzzle all the way to 250 yards using most 5.56 ammo. It will be right on at 50 yards and at about 220 yards.

[Ironman8]

Jax,

I may be wrong*, but (logically thinking) since the sight is offset, when you line up the sight to your eye, you will have the same POA/POI and offset-to-bore relationship as when using a standard red dot.

After that, it would be user preference as to which zero you want. Being that it is a optic for close in range, I would recommend a 100yd/m zero just because all distances from 1-99 yds/m will be between your zero and -2.xx" low. Meaning that you don't have to account for a holdUNDER...only a holdover (really just an offset) at CQB ranges.

*If I'm wrong, then it's probably something that I'm not accounting for such as physics/ballistics when the gun is canted...

ETA: On your first sight-in at 12yds, you should have done 2" low instead of high in order to get you on paper at 25yds. When I zero to 100yds, I zero first at 7yds and have POI at 2.5" low of POA. This has really worked for me and has proven to be VERY close to actual 100yd zero...well at least minute of man, but I have gotten closer.

Hope that helps...

[markm]

*If I'm wrong, then it's probably something that I'm not accounting for such as physics/ballistics when the gun is canted...

As long as the gun is canted so the sight is upright and directly over the bore... everything else should be cool.

[Ironman8]

As long as the gun is canted so the sight is upright and directly over the bore... everything else should be cool.

That's what my logical mind told me, but after getting into imaginary numbers and other such nonsense in college...well I realized that logic sometimes doesn't always prevail, and I'm not usually as smart as I think I am

[Failure2Stop]

As long as the gun is canted so the sight is upright and directly over the bore... everything else should be cool.

Yup.
While offset sights are more prone to being used when not in perfect positioning, the effect of canting at applicable distances (3 to 100 meters, with most under 50 meters) will not significantly disrupt your chi.

FWIW- I use a 100 meter zero for my offset sights, with the gun canted to have the sight in as "correct" a relationship with the barrel as possible during the zeroing process. A front rest helps greatly.

[markm]

the effect of canting at applicable distances (3 to 100 meters, with most under 50 meters) will not significantly disrupt your chi.

That's true. Not much Lob in 100 meters at all.

[jaxman7]

Ironman, sorry meant to say low on the 12 yard sight in.

Appreciate the replies to all.

What has me confused is that with a 25 yard zero why would it be almost 3 inches high at 50? Standard thinking would lead me to assume that if sighted in at 50 your impact at 25 would make around one inch low.

I wanted to use a 50 yard zero but with a three inch variance from 25-50 yards?! Maybe the stars weren't lining up for me today or something. I don't know but this 3 inch elevation change within 25 yards has me stumped.

The off set RDS is just an experiment for now. Just to see if I like it and would be just fine without it-minus having to rapidly change target distances-as the optic on that gun is a TR24.

-Jax

ETA: I would say that something could be wrong with the MRDS but it worked and adjusted for zero fine on my other rifle.