My POI moved downward as I moved the target closer. I started at 7 yards, went to 5, then to 3. Groups stayed tight, they just moved lower and lower the closer the paper got to me. Is this this downward trend a natural thing like mathematics based or is it me (or both)? If matters, my G26 is zeroed at 10 yds. Thanks.
Since you said zeroed at 10 yards I’m assuming RDS.Originally Posted by LowAndLeft
10 yards is super close to zero at.
Yes for height over bore POI and holdover.
10 yard zero is going to give you a very wide swing from 3 yards to 25 yards.
Yes, I run a red dot optic.
Yes, as the range shortens, and your dot sight picture is on the center, it will intersect lower and lower.
Graphically below. Sight picture is the blue line, bullet path is the red line.
The maximum shift in POI is the optic height over bore axis distance. For a G26 with a typical MRDS (a RMR, or 507c perhaps), that will be in the region of 0.9". If you are seeing your groups move down more than that, something else is going on.
Last edited by RJ; 01-18-2023 at 06:57 AM.
Great graphic...Yes, as the range shortens, and your dot sight picture is on the center, it will intersect lower and lower.
Graphically below. Sight picture is the blue line, bullet path is the red line.
The maximum shift in POI is the optic height over bore axis distance. For a G26 with a typical MRDS (a RMR, or 507c perhaps), that will be in the region of 0.9". If you are seeing your groups move down more than that, something else is going on.
As your target moves further away from the zero distance, POI would expect to go up, for similar reasons.
"No free man shall ever be debarred the use of arms." - Thomas Jefferson, Virginia Constitution, Draft 1, 1776
A lot of comp shooters with zero their RDS at 18 yds. Then check to see what their POI is at 5, 7, 10, 15, and 25 yds. My experience is the difference at the other distances is negligible w/ an 18 yd zero, especially when shooting at match speed.
On my PCC I have two optics mounted, one upright and the other at a 45 deg offset for the hard leans. Initially I zero’d the upright dot at 25 yds and the offset one at 7 yds, figuring if I needed the offset it was going to be on close awkward shots. My only excuse was it made sense at the time… I ended up shooting with the offset optic on a target that that was 25-ish yds out with a No-Shoot partially covering the lower half of the A-zone. Yup, ended up hitting lower than POA and tagged the NS.
After that I zero’d both optics @ 18 yds.
FWIW, I also zero the RDS on my carry gun @ 18 yds.
Just as consideration, I wouldn’t zero a PCC at 18 yards because the higher height over bore makes the geometry more extreme.
Its a C-more slide ride, so not as tall as most optics w/ a traditional AR 1/3 or co-witness mount.
Doesn’t sway my opinion. I mounted a Romeo 3 M on the rail of an MPX.
I zero at 25 yards because I don’t want to have any hold under at any distance.
The amount of hold over is negligibly different.
This is where having a 64MOA reticle for close hold overs is nice.
The issue is that a lot of people think they’re zeroing at a certain distance but when they confirm farther… it turns out not to be the case.
I don’t want to send any rounds over the target at any distance. For targets that are rooted to the ground, staying under the dot is better philosophically for me.
Even with a low mount, a long gun optic will still have twice the height over bore of a pistol.
RJ, that graphic helps a lot as I'm def a visual learner. BTW, the optic is a 407C on my 26 and a 507C on my 17.Yes, as the range shortens, and your dot sight picture is on the center, it will intersect lower and lower.
Graphically below. Sight picture is the blue line, bullet path is the red line.
The maximum shift in POI is the optic height over bore axis distance. For a G26 with a typical MRDS (a RMR, or 507c perhaps), that will be in the region of 0.9". If you are seeing your groups move down more than that, something else is going on.
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