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View Full Version : Sighting in today... 50yd and 25yd zero



Mia'sUncle
04-18-2015, 10:37 PM
My ar I went with a 50yd zero. I was experiencing a bit of impact shift with the ammo. At 50 yds I was all around the bullseye and at 150 shooting slightly high. I had a hard time nailing the steel plate. I'm guessing it was 4". I think I'm going to save the 55gr for plinking and new shooters and move to 69 or 77 (1/7 barrel). I have a feeling the 55gr aren't giving me all that the upper is capable of. Optic Bushnell 1-4 with target turrets? Wth? Anyway for now, it's okay. Cheap and usable. Sig m400 upper, cmc 3.5 trigger.

300bo ar pistol. 8.25" barrel, hardened arms upper. Flash can, eotech Xps2-300, 3x primary arms magnifier, 3.5 cmc trigger, 220gr remmington subs. 50yds, top impact point around the bullseye (fair amount of shifting) too much drop at 150yds to use the lower impact point. Looks like 50yds and 100yds with subs. I was running out of time so I got the pistol in "home defense shape". No supers. The eotech called for a 50/200yd zero. That's going to change to a 25yd zero next time I go out. Subs just don't function well at longer ranges.

300bo remmington 700 sps tactical aac, sightron siii 3.5-10 mrad, Harris bipod 6-9", trigger as light as it gets, it is light. Fiocchi 150gr supers. 25yd zero, SINGLE HOLE! 150yds,1 mrad low, smaaashing the 4" steel plate. Sub-Moa all day. This rifle was the star with the adjustable trigger. Huge hammer here. Animals better beware.

RECON762WT
04-20-2015, 09:23 AM
My ar I went with a 50yd zero. I was experiencing a bit of impact shift with the ammo. At 50 yds I was all around the bullseye and at 150 shooting slightly high. I had a hard time nailing the steel plate. I'm guessing it was 4". I think I'm going to save the 55gr for plinking and new shooters and move to 69 or 77 (1/7 barrel). I have a feeling the 55gr aren't giving me all that the upper is capable of. Optic Bushnell 1-4 with target turrets? Wth? Anyway for now, it's okay. Cheap and usable. Sig m400 upper, cmc 3.5 trigger.


Just a few points.

The 50yd and 25yd zeros are holdovers from the Military. They are "generalized" zeros, so you may be dead on at 50yds, but still 2" high of center at 200yds, which is good enough for a military zero, but you can do better with a dedicated 100yd zero. Complicating matters even further, the 50/200 zero is tuned to a specific type of ammo. Switch to a different type and your results will vary. If you went with a true 100yd zero and then figured out your exact DOPE at a specified distance, you would be a lot more exact with your shot placement. See JBMBallistic calculator

I shoot 55gr plinking ammo out of my 1/7's. Its around 2.5MOA ammo. If I switch to my 75gr match loads they shoot around 1MOA or smaller. You can squeeze a lot of performance out of the AR platform (or .223 chambered rifles) by playing around with your ammo selection.

Good luck, happy shooting!

Ol` Joe
04-21-2015, 07:10 AM
Also the height of the scopes center of axis above the bore will change how the sight setting works at different ranges.

everything is a result of angles consisting of the bullets path and the line of sight. A minor change in sight height makes a big difference in the angle when you get out to a couple hundred yards. Don't forget canting the rifle also changes the angles, but in a horizontal direction as well as possibly vertical.
Irons or a low mounted scopes don't show as much variation in POI as a tall sight set up like most have on their ARs.

Mia'sUncle
04-21-2015, 07:10 PM
The remmington sps blackout was shooting fantastic with a 25 yr zero. I just have to determine the holds for various range. I know at 150 it is 1 mrad low. Amazing how accurate that rifle is out of the box.

I'll give it a whirl with a 100yd zero on the 223. I've got some fiocchi 69gr hpbt I'm going to play with next time I get out. The 55gr just weren't shooting well. Good enough but not fantastic.

I've only been trying to shoot rifle, with optics, for a year or so now. Optics were a strange animal at first but it is starting to make sense.

The pistol, 300bo, I believe I'd like to find a close range zero using the high/Low dots on the eotech Xps2-300 and just be happy with a sight in only in subs. The instructions say that a properly sighted in Xps2-300 will already be on for supers. We'll give it a try someday...

Thanks guys.

And as a sort of really crappy and completely uninformative review, sightron makes some robust scopes. I've got an s3,it's been through some harsh treatment, and it dials amazing.