Installed Dawson sights, Now i have a question

Detritus · Nov 6, 2018

A while back I put a Dawson adjustable sight set on my 1911 (as in I did so, no "Professionals" involved). after adjusting for elevation, the rear sight looks a little high to me...

https://www.flickr.com/photos/31838309@N03/
Best pic I could manage tonight using the camera in my phone.

So am I right in that this is an abnormally high adjustment to zero the gun? or is this actually normal for this sight style?
And if it is too high, what corrective action to take? (shorter front sight right?)

as always, thanks in advance for any info or advise.

ColtPythonElite · Nov 6, 2018

Looks way high to me.

Detritus · Nov 6, 2018

ColtPythonElite said:
Looks way high to me.

well that answers that, at least it's not just me.

Looking back on it I can't remember how I came to decide which height to buy for front F/O sight (it's the .190" tall x .100" wide serrate partridge). looks like somehow I "chose poorly"

I can live with it till I get around to buying a shorter front (probably the .180" tall version, since that's the shortest Dawson recommends for this rear), just wanted to make sure I wasn't just being paranoid.

9mmepiphany · Nov 7, 2018

That looks way high.

Were you zeroing your sight from a rest?

Detritus · Nov 7, 2018

9mmepiphany said:
That looks way high.

Were you zeroing your sight from a rest?

Best I could with what I have, Sandbag on a Hornady Delta-Rest.

BTW, It's been around 5 months since I actually zeroed it, so details of technique etc are just a little fuzzy. I just didn't get around to taking a picture till today.

jmorris · Nov 7, 2018

If your hitting where you are aiming it’s not too high. I might get a shorter front sight though.

Looks like you might have a front sight intended to be used with a bowmar rear.

drband · Nov 7, 2018

Try again from a rest and really concentrate on technique. That pic shows the rear as really high. I would be surprised if that's the correct elevation for your installed front sight. If it still needs that rear height, yes, I would try a shorter front sight.

WrongHanded · Nov 7, 2018

I think I read something about Dawson Precision having some sort of guarantee, along the lines of them replacing sights to get you zeroed if what you bought doesn't work. I'm not sure how helpful that is, but perhaps if you double check you POA/POI and call them, they may be willing to assist you.

Detritus · Nov 7, 2018

jmorris said:
Looks like you might have a front sight intended to be used with a bowmar rear.

the front sight is .190" high, the listed "appropriate height range" for this rear sight is listed on the Dawson website as .180-.200". I picked .190" because it was right in the middle I thought least likely to be too high/low. I wasn't able to measure my front sight beforehand due to it having been removed from the slide and then dropped in a small parts bin already

(I HAD been preparing to start a frame up rebuild, then changed my mind)

drband said:
Try again from a rest and really concentrate on technique. That pic shows the rear as really high. I would be surprised if that's the correct elevation for your installed front sight. If it still needs that rear height, yes, I would try a shorter front sight.

WrongHanded said:
I think I read something about Dawson Precision having some sort of guarantee, along the lines of them replacing sights to get you zeroed if what you bought doesn't work. I'm not sure how helpful that is, but perhaps if you double check you POA/POI and call them, they may be willing to assist you.

Sent an e-mail to Dawson early this morning, got the following response

Hello,

My advise is to adjust the rear sight down to the bottom of the travel and then back it off one full turn from the bottom. Then re-shoot the pistol. Use the sight picture you want to use and let me know how far off the pistol is shooting. I also need to know the distance to the target and the sight radius of the pistol. With that info, I can calculate how tall a front sight you need.

so when I get a chance to hit the range again I will be doing just that.

9mmepiphany · Nov 7, 2018

Detritus said:
so when I get a chance to hit the range again I will be doing just that.

It is really important to back off that one full turn from the bottom.

Also pick a distance to sight in where you're able to group consistently (1-2"), as opposed to a group larger than the required adjustment, but also far enough that the displacement of the intended POI is easily discernible.

drband · Nov 7, 2018

Detritus said:
the front sight is .190" high, the listed "appropriate height range" for this rear sight is listed on the Dawson website as .180-.200". I picked .190" because it was right in the middle I thought least likely to be too high/low. I wasn't able to measure my front sight beforehand due to it having been removed from the slide and then dropped in a small parts bin already (I HAD been preparing to start a frame up rebuild, then changed my mind)

Sent an e-mail to Dawson early this morning, got the following response

Hello,

My advise is to adjust the rear sight down to the bottom of the travel and then back it off one full turn from the bottom. Then re-shoot the pistol. Use the sight picture you want to use and let me know how far off the pistol is shooting. I also need to know the distance to the target and the sight radius of the pistol. With that info, I can calculate how tall a front sight you need.

so when I get a chance to hit the range again I will be doing just that.

The folks at Dawson Precision are really great. I always go to them first if I need sights!

Detritus · Nov 9, 2018

Well, I just followed the first part of the instructions i received in reply from Dawson, looks like this may come down to me bing inexpereinced with the sight type, and a worry wart.
the "baseline sight setting" they wanted me to use, as listed/quoted in my previous post, turns out ot be exactly where the sight is set in the picture at top.

unless i get another email back from them to the effect of "That doesn't sound right" i'm just going to let it go and get on with shooting

WrongHanded · Nov 10, 2018

Detritus said:
Well, I just followed the first part of the instructions i received in reply from Dawson, looks like this may come down to me bing inexpereinced with the sight type, and a worry wart.
the "baseline sight setting" they wanted me to use, as listed/quoted in my previous post, turns out ot be exactly where the sight is set in the picture at top.

You mean these instructions?

Detritus said:
My advise is to adjust the rear sight down to the bottom of the travel and then back it off one full turn from the bottom. Then re-shoot the pistol. Use the sight picture you want to use and let me know how far off the pistol is shooting. I also need to know the distance to the target and the sight radius of the pistol. With that info, I can calculate how tall a front sight you need.

Because the sight in the picture of your OP is all the way up, not all the way down.

9mmepiphany · Nov 10, 2018

That does seem awful high for only one full turn...maybe it's just the angle.

What does it look like all the way down?

Detritus · Nov 10, 2018

9mmepiphany said:
That does seem awful high for only one full turn...maybe it's just the angle.

What does it look like all the way down?

all the way down the bottom of the sight is against the top of the slide with no visible gap.

it might be the angle

if I had a third hand (or 2nd person awake in the house) i'd try and take a picture of it with a dial caliper in the same frame. can't get a precise measurement but the gap at "one turn 'up' " looks to be about 0.10"

Doublehelix · Nov 10, 2018

Detritus said:
can't get a precise measurement but the gap at "one turn 'up' " looks to be about 0.10"

Yeah, the picture makes it look like a *lot* more than 0.10", and you posted here because you felt something was off. If it works, and you are happy however, then that is a good result.

I don't have the Dawson rear sights (front only), but here is what my 1911-based guns look like (the second picture looks crooked because of the camera angle):

WrongHanded · Nov 10, 2018

Okay, I don't know how helpful this will be but my Sig STX looks to have the same sight design. So I bottomed it out and then took it a full turn up.

At the very rear of the sight, it measures around .080" up from the slide where I can get calipers on it (not directly in the center of the slide though). And Sig's do seem to have a flatter slide top than is traditional.

For reference, at 25 yds my zero is 5 clicks up from bottom to get a #2 hold with 230gr ammo. 5 clicks is just less than half a turn.

I suppose, if you set the rear sight to where you'd like to have it, and then shoot a few groups from a bench at a known distance to record the results, you could use trigonometry to work out how much change you need in a front sight. This is how I work it out.

Edited to add: Actually, you don't need to use trig, you can just work it out proportionally. For example:

If your group is 2" low at 25yds (900"), and your sight radius is say 7" then; 2 ÷ 900 x 7 = 0.0156; so your front sight would need to be 0.0156" lower. If the sights come in increments of 0.01" then you have to decide if you want to go down 0.01" and raise the rear a little from its current position, or go down 0.02" with the front sight and low the rear a little more (assuming you can).

Detritus · Nov 10, 2018

WrongHanded said:
the sight in the picture of your OP is all the way up, not all the way down.

The sight as pictured, is in the almost dead middle of it's vertical travel range, (within a click or two) it is one full turn "up" from where the sight bottoms out, and has a further 1 to 1-1/4 turns worth of usable adjustment available (based on the idea that the last 1/4-1/2 turn worth of screw travel should be left alone to keep the screw from stripping out).

I think that the camera angle or lighting make it look higher than it really is. the gap between the top of the slide and the bottom of the sight, as adjusted, is around .100"

WrongHanded · Nov 10, 2018

Detritus said:
The sight as pictured, is in the almost dead middle of it's vertical travel range, (within a click or two) it is one full turn "up" from where the sight bottoms out, and has a further 1 to 1-1/4 turns worth of usable adjustment available (based on the idea that the last 1/4-1/2 turn worth of screw travel should be left alone to keep the screw from stripping out).

I think that the camera angle or lighting make it look higher than it really is. the gap between the top of the slide and the bottom of the sight, as adjusted, is around .100"

Yeah, I shouldn't have put that as bluntly as I did. I also shouldn't have assumed it was all the way up. It just appeared as though it was, which could well be an optical illusion from the lighting and angle of the picture.

What load did you zero with, and at what distance with what sight picture?

Detritus · Nov 10, 2018

WrongHanded said:
What load did you zero with, and at what distance with what sight picture?

if I remember this batch of reloads was. 230gr coated LRN over 4.7gr of IMR Target (it's been six or seven months since I zeroed the sights, it's been a frustrating year as far as range time)

Final distance was about 20yrds, using a six o'clock hold on the dot I was using as an aiming point*

*note: target(s) used were not typical gridded or paper bullseye types, I used a USPSA target with one of those orange dot stickers slapped on as a visible and consistent aiming point. I use this gun as my USPSA gun, so at least to my logic, it makes sense to zero it on the same target type. the Dot sticker was added b/c when zeroing you have to have a consistent POA.

9mmepiphany · Nov 10, 2018

Detritus said:
I use this gun as my USPSA gun, so at least to my logic, it makes sense to zero it on the same target type.

I never thought of that.

I've always zeroed on a diamond so I'd have a narrow point to center the front blade. I use what is commonly called POA/POI...sight picture #2

Detritus · Nov 10, 2018

9mmepiphany said:
I never thought of that.

I've always zeroed on a diamond so I'd have a narrow point to center the front blade. I use what is commonly called POA/POI...sight picture #2

When Zeroing, POA/POI is what I'm actually after as well. but since 90% of my shooting is at USPSA "Metric" silhouette style targets, and the distance I want my "zero" to be at is a little further out than many will try for. it's simpler for me to take the USPSA target, stick a dot on it, take a six o'clock hold on the dot, and adjust so that my POI is just below the dot.

in other words i'm using the dot as a fixed reference, not trying to hit it.

Now I need to get back in practice again, so I can get back to where I could actually put 8-shots into an index card at 20yrds again....

Detritus · Nov 12, 2018

Have received a further response on this from Dawson. figured i'd share.

If you don't like the way the sight looks when it is 12 clicks up from the bottom, adjust it back down 6 clicks and re-shoot the pistol. Let us know how far off it is shooting and the distance to the target. Wether the sight is one turn or 1/2 turn up from the bottom of the travel is personal preference. The full turn of the screw just gives you more adjustment if your point of impact changes due to ammo changes.

So I think for now i'll leave things as is and maybe at a later date adjust down 6 clicks and resight.

Installed Dawson sights, Now i have a question

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