If I have a red dot that is installed and zeroed can I use it to then zero a set of iron sights? Also if it’s the other way to around? Can I just line up my red dot with the front and back iron sight in order to zero it? Just trying to save some time and ammo.
Yes you can, but once you do you need to at the very least shoot a 3 or 5 shot group to verify the zero.
I did exactly that with some PSA kit rifles. Got the irons on at 50, mounted and lined up the dot, then fine tuned at 100. Super quick and easy, didn’t need much ammo either.
Just make sure that your sights and red dot are on the same horizontal plane. Measure the vertical distance between the bore or top of your rail and the sights and the red dot. Some claim “co-witness”, “absolute co-witness”, and other things that don’t really have a technical standard. For instance, I’ve seen some people say that it means the sights and the optic all line up perfectly, and some that say that it just means you can use your iron sights through the optic if it fails, but they don’t necessarily line up.
The dot will line up with both absolute co-witness and lower 1/3rd depending on your cheekweld. The one that won’t line up is 1.93, which is often used with NODS and atpials.
If you have your iron sights zeroed - and your red dot is a height to absolute co-witness, then you can zero the red dot by lining it up.
But I don’t expect that the reverse is true.
Not 100% certain on this though.
Zero’ed at 100 is not the same as Zero’ed at 300 or 400 yards.
Side-stepping the idea that this might involve a “hook” or a “slice” …
Whatever I do at 100 yards, I notice additional tweaking on the scope when I start shooting at 300 yards.
My favorite Left Right zero happened once when I was concerned whether my older PSA 20" 308 upper was Zero’ed.
I took one shot at the 400 yard steel with a 110 grain Hornady GMX copper bullet.
Obviously I couldn’t see the cable.
But the steel dropped. Pretty sure I hit the cable. Therefore, it was close-enough-to-centered.
I have noticed a definite “hook” or “slice” in a 350 Legend.
Very repeatably, I had to set it so that it was shooting a little to the left at 100.
Then it would move to the right edge of the target at 300.
Using those 16 x 20 inch paper targets.
This is with a Low BC bullet, the Hornady 165 grain.
Red dot newbie here (don’t actually have it yet, but I will soon). Found this video…seems pretty good, anyone have any thoughts?
Also, would that method of zeroing be correct for ANY brand of red dot? I am looking at the Holosun HS510C/HM3X Combo.
I use the red dot charts.