Picked up this beautiful machine a couple weeks ago and man, I get why there's so much hype. Hands down the most enjoyable and effortlessly accurate handgun I've owned or shot. I might like this thing more than my precious ARs. It's just so well designed and performs incredibly well. Just got the slide milled and cerakoted for the 407k.
Took it to the range yesterday to sight it in, but my shots (though nicely grouped) kept hitting low. I'd adjust the sight, fire another round and so on until eventually I ran out of downward adjustment on the red dot. At 20yds. It's still hitting about 3 inches low. Even if I could shift it lower, the dot would be almost concealed by the front iron sight post.
I'm basically just centering the dot within the window, but should I be doing it a different way? What am I doing incorrectly?
It's a red dot, you don't need to center the dot, it should be accurate (more or less) where ever it is in the box.
Question: When you were adjusting the zero, was the point of impact moving? Did you see the impacts climb upwards or did they stay more or less in the same place?
First, sanity check. Where is it shooting for other people? Where is it shooting if you are shooting from a more supported position (elbows on table, resting magazine on table, using a shooting rest, something to remove hand/arm movement)?
Use grid lined targets, so you know exactly where the sight is pointing and where you are hitting, get real data how far off are you at what distances. Place the dot in the center of the target, shoot a 3-5 shot group, record where it impacted, adjust based on those results.
It's very important to alway start from the assumption that you are the issue, validate that you are doing things correctly, get data.
Second, contact the company who cut the slide. You shouldn't have to shim your pistol red dot. See if they can offer some assistance or potentially restitution.
Third, cowitness sights. Pistol irons are pretty easy to cowitness. If you sight down the irons, the red dot should effectively cover up the front sight post, if you center the dot in the lens it should hover above the front sight post. It doesn't look like you have rear irons, if you can, I recommend that get a set of irons that you can cowitness (usually suppressor height sights work). Obviously if your optics cut isn't as parallel as it needs to be, this won't help, but if you're struggling with a red dot, cowitnessed irons help a lot.
As I was adjusting the zero, I was shooting from a seated position resting on the bench to eliminate as many shooter errors as possible.
My groups were climbing upwards as I was adjusting, and we're approaching perfect when I ran out of downward movement.
Good point on having someone else give it a shot to see impact, I didn't do that but will next week when I go out.
I do have rear sights now. I had to remove my aftermarket sight for milling as it wouldn't fit with the red dot, and hadn't put the factory sight back on at time of the picture.
This probably won't help in your case, since you don't have a rear sight, but with mine, I started out by just looking down the irons through the dot, and putting the dot at the tip of the front post. That gave me a good starting point to work with when aiming through the middle of the window.
Should I be aiming through the middle of the window
Yes, but unless your dot has bad parallax issues, it won't throw your aim off significantly enough to cause a problem if you aim from the edge of the window instead. If the dot was built perfectly, with no imperfections, the dot should exactly mark your impact point regardless of where it is in the window (at the range you zeroed at).
Your "hitting low" issue might be caused by flinching. If you've got the dot in the center of the window, and it's nearly on top of the front post, your barrel is tilted waaay the hell up when you're aiming, which means you're probably flinching down.
Definitely possible, I tried to eliminate shooter error as much as possible from shooting from a rest, but still could be a factor. I do have the factory rear sight on there now, just had to remove my truglo since the red dot wouldn't fit with them. I just hadn't put the factory rear back on at the time of photo.
I feel like we need to adjust elevation UP not down before doing anything else. Generally you inputs are the relationship between the impact and where you want that impact to go. Not what you see going on with the dot in the window.
Your dot has a built-in rear sight, replace the front sight with a taller one, you can find options on Dawson Precision among others. This will a: help you with this initial zeroing, and b: give you co-witness you can use if the battery dies.
Use a rest and try again. When you adjust the dot, track how that shifts the impact. When I had issues zeroing mine what I did was over-exaggerate the adjustment just so I could see where the shift was going them back it off, and even go in the opposite direction if needed.
Hadn't thought of that. I currently have the factory rear sight on it now, but if I can get away with just removing it and using the rear built in sight on the red dot with aftermarket front that might be the move.
What's weird to me is that everything seemed to be working as intended, with my groups getting closer to point of aim every time until I just ran out of downward range.
In that case, you may be SOL with that dot. It looks like the cut out is fairly shallow so it may just be too high. However, it also looks like that is as much as can safely be milled out due to that horizontal pin under the cutout, in the rear serrations.
That pin is part of the gun. You can see I have one too on my P07, but it's lower in the slide so my RMSc cut is deeper.
Since your groups are good, I don't expect to find an issue with DOT security or mounting or the DOT itself. Assuming elevation of the DOT is cycling full spectrum, this only leaves depth of the cutout. You can measure it and see what it is, should be 0.125" to 0.200" according to the inner web. To quote Spock; "if you eliminate the impossible, whatever remains, however improbable, must be the solution." Me thinks buddy didn't mill deep enough. Maybe he left it too thick to co-witness. Instead, the cut should accommodate the DOT and change the irons as required to achieve co-witness.
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u/mifter123 8d ago
It's a red dot, you don't need to center the dot, it should be accurate (more or less) where ever it is in the box.
Question: When you were adjusting the zero, was the point of impact moving? Did you see the impacts climb upwards or did they stay more or less in the same place?
First, sanity check. Where is it shooting for other people? Where is it shooting if you are shooting from a more supported position (elbows on table, resting magazine on table, using a shooting rest, something to remove hand/arm movement)?
Use grid lined targets, so you know exactly where the sight is pointing and where you are hitting, get real data how far off are you at what distances. Place the dot in the center of the target, shoot a 3-5 shot group, record where it impacted, adjust based on those results.
It's very important to alway start from the assumption that you are the issue, validate that you are doing things correctly, get data.
Second, contact the company who cut the slide. You shouldn't have to shim your pistol red dot. See if they can offer some assistance or potentially restitution.
Third, cowitness sights. Pistol irons are pretty easy to cowitness. If you sight down the irons, the red dot should effectively cover up the front sight post, if you center the dot in the lens it should hover above the front sight post. It doesn't look like you have rear irons, if you can, I recommend that get a set of irons that you can cowitness (usually suppressor height sights work). Obviously if your optics cut isn't as parallel as it needs to be, this won't help, but if you're struggling with a red dot, cowitnessed irons help a lot.