I have installed a holosun 509t on my G17 mos using ameriglo GL429 sights and a C&h plate. My dot is zeroed at 15yds. The red dot is NOT centered with the irons. It is to the left of the front sight. I have confirmed zero with both the dot and the irons.
Is it normal for the dot to not be centered with the irons?
Yes, it's normal. We issue the G45 with C&H plate, 509T, and C&H low witness irons.
Yes, because the 2 MOA dot on the 509T is much more precise than a front iron sight post. However, I would suggest you confirm your iron sight windage at 25 yards instead of 15 yards as it sounds like your rear iron sight is not perfectly calibrated for windage. A .5 mechanical pencil mark is very handy for making precise adjustments in the dovetail. You may not care enough to go through that for backup irons, but it's helpful to have them adjusted where you can roughly check your dot zero. Windage errors are hard to detect accurately at shorter distances. I would advocate the same for your dot: even if you want a 10 or 15 yard zero, confirm the windage at 25 yards.Originally Posted by DLWinner
Weird. I guess I don’t understand. Is this a 509t specific thing? I’ve installed lots of red dots in the past, and the dot was never to the left of the irons when zeroed. Just seems strange.
If you're trying to cowitness low irons at the very bottom of an optic, there may be significant parallax.
“There is no growth in the comfort zone.”--Jocko Willink
"You can never have too many knives." --Joe Ambercrombie
They’re kinda low.
Your dots are to the left of the front sight too?
Check out this thread and these posts in particular:
I have been experimenting with very low BUIS on my RDS-equipped handguns. This setup uses a rear sight with notch just visible at the bottom of the window, and a shorter-than-normal front sight, which shifts the POI up into the center of the optic window.
The POA remains the same regardless of whether the dot is on. The index is the same with dot and BUIS.
Not surprisingly, I've had numerous questions about this setup--first and foremost whether I can hit anything with the dot off. See below. Low Witness works really well and I recommend giving it a try. If you have a Glock, the switch is especially easy. All that's required is a front sight that's about 0.050" shorter....What @Clusterfrack is doing differently here is having irons that don’t actually place with the dot.
The irons are designed to be “off” but aligned when holding in a traditional dot index (that would put the front sight higher than the notch in a lower 10th co-witness).
...
“There is no growth in the comfort zone.”--Jocko Willink
"You can never have too many knives." --Joe Ambercrombie
Yes, the three of mine are.
Interesting. Does anyone have any idea why this is?
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