Explain sight radius to me

[YVK]

I am trying to understand the trigonometry and visual differences behind the statement "longer sight radius helps with accuracy" and things are not clicking. The online search suggested that longer sight radius brings out any misalignment better. Not sure why; for the same front sight and rear notch widths the longer gun would have wider light bars around the front sight. Would appreciate an explanation.

More to the point, if one took a shorter sight radius gun and stuck a tighter rear sight on it, would that negate any potential disadvantages in regards to accuracy?

[JHC]

I am trying to understand the trigonometry and visual differences behind the statement "longer sight radius helps with accuracy" and things are not clicking. The online search suggested that longer sight radius brings out any misalignment better. Not sure why; for the same front sight and rear notch widths the longer gun would have wider light bars around the front sight. Would appreciate an explanation.

More to the point, if one took a shorter sight radius gun and stuck a tighter rear sight on it, would that negate any potential disadvantages in regards to accuracy?

This ought to be good. Thanks! I think you struck on the reason I didn't see accuracy advantages with not one, but two G34s I tried over the years then sold because I was no more accurate than I was with my 17s. Nor did I see anything special from a G17L. I was applying the same sets of sights to each gun. It didn't occur to me to tighten up the rear notch on the longer barreled gun, and my experience supports the old target shooter preference for thinner light bars. Duh!

[breakingtime91]

Awesome. Watching with interest

[41magfan]

All things being equal, a longer sight radius does allow for more accuracy. But this silliness being advanced that a few millimeters is a deal breaker is pure nonsense.

[breakingtime91]

All things being equal, a longer sight radius does allow for more accuracy. But this silliness being advanced that a few millimeters is a deal breaker is pure nonsense.

But how?

[RoyGBiv]

Forgive the lack of math here, just a quick try at turning the light bulb on.....

Let's say you can line up a given set of sights with the same accuracy on two different guns... one longer than the other. Let's say (extreme example) you're off by 1/2" on both guns. The front sight is pushed left of center by 1/2". Would the two projectiles hit the same point on the target? Which one would be pushed further left?

Here's my back of an envelope drawing...

http://i1373.photobucket.com/albums/ag388/RoyGBiv00/Sight%20radius_zps8vk8qzyq.jpg

I'll leave it to others to address the "smaller sights" question....

ETA: The shorter your sight radius, the greater the deviation between where you'd like your shot to hit and where it actually hits, for the same level of inaccuracy in sight alignment.

[P.E. Kelley]

I cover some of this within this article>>>http://www.shootingillustrated.com/articles/2011/9/23/the-power-of-one/
It really boils down to math. You are allowed greater sight alignment error with a longer sight radius.

[StraitR]

Sight radius, as I see it...

If you disrupt the sights by a finite amount, the longer the sight radius, the less the disruption will show downrange. Take two bullets, place them on a line three inches apart, then move one of those bullets a half inch off that line, then measure the angle. Now put the bullets six inches apart on the line, move one a half inch off the line, then measure angle.

The greater the distance between two points, the less angle of deflection there will be given the same amount of movement of one of those points.

That's my understanding.

ETA: slow on my articulation, looks like RGB beat me to the punch with an illustration that shows what I was trying to say.

[eyemahm]

Not sure why; for the same front sight and rear notch widths the longer gun would have wider light bars around the front sight. Would appreciate an explanation.


I think the why has already been addressed.

For a data point, in case that helps put it in perspective, I found that a full size 4.25 in barrel gun with a 125 rear looked to have about the same light bars as a 5.25 in barrel gun with a 115 rear. The front sights on each were 125.

[JHC]

Sight radius, as I see it...

If you disrupt the sights by a finite amount, the longer the sight radius, the less the disruption will show downrange. Take two bullets, place them on a line three inches apart, then move one of those bullets a half inch off that line, then measure the angle. Now put the bullets six inches apart on the line, move one a half inch off the line, then measure angle.

The greater the distance between two points, the less angle of deflection there will be given the same amount of movement of one of those points.

That's my understanding.

ETA: slow on my articulation, looks like RGB beat me to the punch with an illustration that shows what I was trying to say.

Yes and is it not also generally true that visually you cannot perceive small increments of deviation from proper alignment on short radius vs long radius? I believe that to be my visual perception. That short lever looks true and steady, if it were twice as long, I would perceive it wobbling more or otherwise askew.

[breakingtime91]

Am I weird to think that shorter guns (g19/p2000) track faster? To my eyes the guns cycle faster and with the right technique the recoil impulse isn't that much more when compared to g17/g34 variants..

[GJM]

Am I weird to think that shorter guns (g19/p2000) track faster? To my eyes the guns cycle faster and with the right technique the recoil impulse isn't that much more when compared to g17/g34 variants..

If you mean transition, not weird at all. At first I was puzzled by it, thinking it was an anomaly, but over and over, I find the shorter slide to transition better. The flip side is the longer/heavier slide makes up for it as the targets get smaller/further.

[P.E. Kelley]

Yes and is it not also generally true that visually you cannot perceive small increments of deviation from proper alignment on short radius vs long radius? I believe that to be my visual perception. That short lever looks true and steady, if it were twice as long, I would perceive it wobbling more or otherwise askew.

Yes! I find that with myself and students running 1x optics or irons vs. magnified optics on carbines. The more one perceives error the more apt one if to stab at the trigger.
Perceive less wobble...break better shots.

[GJM]

Yes! I find that with myself and students running 1x optics or irons vs. magnified optics on carbines. The more one perceives error the more apt one if to stab at the trigger.
Perceive less wobble...break better shots.

For this reason, I think a few generations down the road, a RDS for a handgun will have some stabilization feature to minimize dot wobble.

[CCT125US]

Am I weird to think that shorter guns (g19/p2000) track faster? To my eyes the guns cycle faster and with the right technique the recoil impulse isn't that much more when compared to g17/g34 variants..
My P2000 Sk tracks better than my P2000, which tracks better than my P30. I percieve the apex of recoil and the muzzle dip more with longer slides.

[Nephrology]

Honestly, I think sight radius is a concept better applied to rifle iron sights and has been misapplied to handguns. Unless you are competing in bullseye or hunting deer with a handgun at distances beyond 30yds or so, I am not convinced it makes a terribly big difference. In the context of action pistol sports and self defense, I think it is entirely irrelevant.

[GJM]

Honestly, I think sight radius is a concept better applied to rifle iron sights and has been misapplied to handguns. Unless you are competing in bullseye or hunting deer with a handgun at distances beyond 30yds or so, I am not convinced it makes a terribly big difference.

Disagree. Not sure how much time you spend at 25-100 yards, but in that segment, I find sight radius matters much. Shoot P30L better than P30 at distance, Brig Tac better than Centurion, five inch N frame better than 3 inch, and on and on.

[JHC]

Am I weird to think that shorter guns (g19/p2000) track faster? To my eyes the guns cycle faster and with the right technique the recoil impulse isn't that much more when compared to g17/g34 variants..

No doubt about it to my eyes. G26 flattest fastest, G19 next, G17 next. Commander length 1911s better than 5" to my perception. I have assumed part of it was slide mass and slide velocity. Less mass, higher slide velocity; less visual disruption - on top of the visual of the more stable short slide etc. Mostly just spit ballin' though.

[okie john]

All things being equal, a longer sight radius does allow for more accuracy. But this silliness being advanced that a few millimeters is a deal breaker is pure nonsense.

This.

Any increase in radius helps in theory, but in practice it has to be pretty large to show up downrange.

For instance, the sight radius of a G17 (6.49”) is only 1.10” longer than the sight radius of a G26 (5.39”), and most people report that they shoot a G26 almost as well as they shoot a G17.

The difference between the sight radius of a 2” Model 36 (3.375”) and the sight radius of an 8 3/8” N-frame (10”) is bigger and thus more decisive. A Model 94 Winchester with a 20” barrel and factory sights has a sight radius of just over 14”, so it makes sense when people say that a long N-frame shoots like a rifle—it has almost the same sight radius. And that’s one reason why replacing the open rear sight on a rifle with a peep sight makes it easier to shoot well—it increases the sight radius by 40-60%.


This ought to be good. Thanks! I think you struck on the reason I didn't see accuracy advantages with not one, but two G34s I tried over the years then sold because I was no more accurate than I was with my 17s. Nor did I see anything special from a G17L. I was applying the same sets of sights to each gun. It didn't occur to me to tighten up the rear notch on the longer barreled gun, and my experience supports the old target shooter preference for thinner light bars. Duh!

Narrow light bars make it easier to percieve differences in misalignment. Having one bar twice as wide as the other is a red flag that you’re not lined up properly. The thinner the bar, the smaller the amount of misalignment required to fly the red flag, so the easier it is to shoot small groups in slow fire. It’s harder to see the same amount of misalginment with wide light bars.


Okie John

[Edwin]

PDF Warning (http://www.dawson1911.com/images/Instructions/FrontSightHeight.pdf)

[LOKNLOD]

I think that sight radius relative to barrel length is a bigger issue, and is more relevant to rifles than pistols.

If you have short sights and a long barrel, it's a bit like using a pencil holding it only by the eraser. Think of the difference between sights on a carbine-length AR vs on a "Dissipator" setup - it creates parity between sight movement and muzzle displacement.

[Kevin B.]

Guns with a shorter sight radius also tend to bring the front sight closer to the shooter resulting in the front sight, obscuring more of the target than if it were further away from the shooter. This can also affect accuracy.

[StraitR]

No doubt about it to my eyes. G26 flattest fastest, G19 next, G17 next. Commander length 1911s better than 5" to my perception. I have assumed part of it was slide mass and slide velocity. Less mass, higher slide velocity; less visual disruption - on top of the visual of the more stable short slide etc. Mostly just spit ballin' though.

One of the frustrations of shooting smaller guns for me is my inability to track the sights fully through recoil. As an example, for me, the sights sort of disappear and then reappear on the G43 vs being able to watch them go up and then down on a 17, even a 19. I'm not sure if everyone agrees, but this is what I think of when talking about "driving the gun". So when that process is disrupted, I can't drive it so much as guesstimate where that front sight will reappear next.

I don't know why I've been unable to make the association, but your comments make clear that shorter sight radius guns (G43) tend to move through that arch at much greater pace than longer sight radius guns (19/17), hence my difficulty tracking the sights. With time and experience I suspect that tracking the 43 sights will become easier, like it has on other pistols, but this helps a little with the " but why" part that frustrates me.

I realize that there are other key factors, such as slide weight/velocity as mentioned above, and individual visual acuity as well as experience, but I've never considered sight radius as a contributor.

Lightbulb. Gracias.

[YVK]

Am I weird to think that shorter guns (g19/p2000) track faster? To my eyes the guns cycle faster and with the right technique the recoil impulse isn't that much more when compared to g17/g34 variants..

Yes. P30 and 30L is a good pair to see this because they have identical grips (ability to control ) while 30's slide is lighter. G17 and G34 aren't as illustrative for me because slides weigh the same.
Unlike CCT, I feel that 2000sk dips lower and I attribute it to a double recoil spring. My 2000 is in a different caliber so I can't say.

This post was born out of attempt to get the same long distance accuracy out of my P30 as I get our of 30L.

[GJM]

This post was born out of attempt to get the same long distance accuracy out of my P30 as I get our of 30L.

Why didn't you just ask that -- easy, put a RDS on your P30 (optics division awaits you).

[JHC]

One of the frustrations of shooting smaller guns for me is my inability to track the sights fully through recoil. As an example, for me, the sights sort of disappear and then reappear on the G43 vs being able to watch them go up and then down on a 17, even a 19. I'm not sure if everyone agrees, but this is what I think of when talking about "driving the gun". So when that process is disrupted, I can't drive it so much as guesstimate where that front sight will reappear next.

I don't know why I've been unable to make the association, but your comments make clear that shorter sight radius guns (G43) tend to move through that arch at much greater pace than longer sight radius guns (19/17), hence my difficulty tracking the sights. With time and experience I suspect that tracking the 43 sights will become easier, like it has on other pistols, but this helps a little with the " but why" part that frustrates me.

I realize that there are other key factors, such as slide weight/velocity as mentioned above, and individual visual acuity as well as experience, but I've never considered sight radius as a contributor.

Lightbulb. Gracias.

When the 43 front sight disappears, is it moving out of your vision of just so fast it blurs into disappearance? I haven't shot a 43 yet but my perception is the shorter Glocks are reciprocating back and forth flatter and with less disruption of my sight tracking - which must be relative to my target area also. I keep using "perception" for that's all it is. For all I know they are moving differently than I am perceiving.

I think I'm gonna experiment early next year with the KKM compensator deal on a G19 along these lines.

[StraitR]

I haven't shot a 43 yet but my perception is the shorter Glocks are reciprocating back and forth flatter and with less disruption of my sight tracking - which must be relative to my target area also. I keep using "perception" for that's all it is. For all I know they are moving differently than I am perceiving.

I think I'm gonna experiment early next year with the KKM compensator deal on a G19 along these lines.

I can't say that I think shorter Glocks shoot flatter, although they very well could, but there's lots of variables (shooter skill, hand size, grip strength) and subjectivity as well as perception like you pointed out. Curious to see what you find, please share. I love discussions of science, or even subjective pseudo-sclence, as it applies to the technical aspects of shooting.

[YVK]

Why didn't you just ask that -- easy, put a RDS on your P30 (optics division awaits you).

Do you have any suggestions what kind of co-witness to strive for?

[Mr_White]

Regarding shorter slides cycling faster and transitioning better - I think this is largely perception/sense of feel talking. Even if a G34 slide, for example, cycles slower than a G26 slide, I don't think it matters in terms of split time. Is anyone's trigger finger outrunning the cyclic rate of the gun? I don't think so, especially on a trigger the length and weight of a stockish Glock. Does anyone get consistently faster splits with a G26 than a G34? I don't know but I am betting probably not. I've seen plenty of low teens split times reported by G34 shooters. I don't remember seeing those times reported by G26 shooters, but maybe I just haven't seen enough.

Draws and transitions are one area where people often feel like a shorter gun is 'better.' I think it just feels easier and I question whether it is actually objectively better in terms of time spent transitioning. I've not tested that myself with target transitions, but at one point, someone made the argument to me that a shorter gun drew faster than a longer gun. I tried finding a difference in draw time with a shorter vs. longer slide and could not detect any on the timer, though the shorter gun felt better.

But I do think it's a subjective advantage to like the feel of how your gun moves in recoil, and some people do prefer how shorter guns feel. That can be worthwhile even if it doesn't show up on the timer.

Has anyone here measured transition times with similar shorter and longer guns and found an objective difference, as opposed to preferring how they feel?

[Virtuosity Student]

Bear with me, it has been a few years since I have done trigonometry.

http://i76.photobucket.com/albums/j22/CC49INC/Sight%20Radius_zps5b8rzg4z.jpg

Ok the picture is not to scale but it is a representation of my math in regards to how sight radius affects horizontal accuracy over distance.
As sight radius increases the angle that is created from a shift in the front sight decreases. For example, using a 1mm shift in front sight (.0394”) with a 6.02” sight radius (Glock 19) you can calculate the angle created by the front sight shift.
tan⁡〖x= (.0394)⁄6.02 which equates to a .000114229191 ratio.〗
To get the angle, use arctangent (.000114229191) which equals .006544850513 degrees.
Now using a known target distance, you can calculate the impact shift on the target using the formula:
tan⁡〖(.006544850513)= (opposite (impact shift))⁄(adjacent (known distance))〗
Multiply known distance IN INCHES * tangent of angle to get impact shift in inches.

My calculations show:
Glock 19 at 7 yards: .029” 25 yards: .206”
Glock 17 at 7 yards: .027” 25 yards: .191”

I used 1mm as a reference for sight shift. How many people could noticeably identify a 1mm shift in front sight?
I then looked to see if a narrower rear sight would change anything and it does not as it does not affect the angle created by a front sight shift. I does however narrow the gap possibly making a front sight shift more identifiable.

[psalms144.1]

Bear with me, it has been a few years since I have done trigonometry.

http://i76.photobucket.com/albums/j22/CC49INC/Sight%20Radius_zps5b8rzg4z.jpg

Ok the picture is not to scale but it is a representation of my math in regards to how sight radius affects horizontal accuracy over distance.
As sight radius increases the angle that is created from a shift in the front sight decreases. For example, using a 1mm shift in front sight (.0394”) with a 6.02” sight radius (Glock 19) you can calculate the angle created by the front sight shift.
tan⁡〖x= (.0394)⁄6.02 which equates to a .000114229191 ratio.〗
To get the angle, use arctangent (.000114229191) which equals .006544850513 degrees.
Now using a known target distance, you can calculate the impact shift on the target using the formula:
tan⁡〖(.006544850513)= (opposite (impact shift))⁄(adjacent (known distance))〗
Multiply known distance IN INCHES * tangent of angle to get impact shift in inches.

My calculations show:
Glock 19 at 7 yards: .029” 25 yards: .206”
Glock 17 at 7 yards: .027” 25 yards: .191”

I used 1mm as a reference for sight shift. How many people could noticeably identify a 1mm shift in front sight?
I then looked to see if a narrower rear sight would change anything and it does not as it does not affect the angle created by a front sight shift. I does however narrow the gap possibly making a front sight shift more identifiable.I normally don't quote entire posts, but the level of sheer MATH involved in the above bears repeating.

Not that I understand an f'ing thing he said - I dropped Calculus in 12th grade to take Driver's Ed, but damn, that's some MATH!

[JHC]

Regarding shorter slides cycling faster and transitioning better - I think this is largely perception/sense of feel talking. Even if a G34 slide, for example, cycles slower than a G26 slide, I don't think it matters in terms of split time. Is anyone's trigger finger outrunning the cyclic rate of the gun? I don't think so, especially on a trigger the length and weight of a stockish Glock. Does anyone get consistently faster splits with a G26 than a G34? I don't know but I am betting probably not. I've seen plenty of low teens split times reported by G34 shooters. I don't remember seeing those times reported by G26 shooters, but maybe I just haven't seen enough.

Draws and transitions are one area where people often feel like a shorter gun is 'better.' I think it just feels easier and I question whether it is actually objectively better in terms of time spent transitioning. I've not tested that myself with target transitions, but at one point, someone made the argument to me that a shorter gun drew faster than a longer gun. I tried finding a difference in draw time with a shorter vs. longer slide and could not detect any on the timer, though the shorter gun felt better.

But I do think it's a subjective advantage to like the feel of how your gun moves in recoil, and some people do prefer how shorter guns feel. That can be worthwhile even if it doesn't show up on the timer.

Has anyone here measured transition times with similar shorter and longer guns and found an objective difference, as opposed to preferring how they feel?

I'm sure your right about the objective mechanics operating here. If, IF there is any time to be saved for me, it's in the improved perception which is connecting to my discrimination of seeing what I need to see from the sights to shoot at some chosen pace/speed.

When Kevin B recently showed me a specific drill/test, it was clear it was a see and speed drill. 5 yards on a B8 target. Load with 15. On GO shoot 15, then reload and shoot 1. All 16 had to be in the black. There was a time standard which was not revealed; I was instructed to shoot as fast as I could guarantee hits in the black. Later I learned I exceeded standard due to penalties for shots out of the black. (Kevin does that a fair bit. "What's the standard?" - - - "I'll tell you when you are done. Shoot as fast as you can with all hits." )

The point is when he described it; I put up my G17 and reached for my RTF2 G19. The gun I have the most confidence in seeing fast for close range games.

I probably live with many of my own myths. :D

[RoyGBiv]

My calculations show:
Glock 19 at 7 yards: .029” 25 yards: .206”
Glock 17 at 7 yards: .027” 25 yards: .191”

I used 1mm as a reference for sight shift. How many people could noticeably identify a 1mm shift in front sight?
I then looked to see if a narrower rear sight would change anything and it does not as it does not affect the angle created by a front sight shift. I does however narrow the gap possibly making a front sight shift more identifiable.
Math!!! http://texaschlforum.com/images/smilies/hurray.gif

I was way too lazy to do the math this morning. And I hate trigonometry :p . Nice!

[eyemahm]

Regarding shorter slides cycling faster and transitioning better - I think this is largely perception/sense of feel talking. Even if a G34 slide, for example, cycles slower than a G26 slide, I don't think it matters in terms of split time. Is anyone's trigger finger outrunning the cyclic rate of the gun? I don't think so, especially on a trigger the length and weight of a stockish Glock. Does anyone get consistently faster splits with a G26 than a G34? I don't know but I am betting probably not. I've seen plenty of low teens split times reported by G34 shooters. I don't remember seeing those times reported by G26 shooters, but maybe I just haven't seen enough.

Has anyone here measured transition times with similar shorter and longer guns and found an objective difference, as opposed to preferring how they feel?

This is an extreme example, because the slide of the 9mm USP Expert is much heavier than the g17/34 (I believe it comes stock with an 8 lb recoil spring!), but after getting frustrated with what felt like out running the slide, I looked at video and it turned out that the slide took around a tenth of a second to completely return to battery. This compares to a g17 at about half the time (.05) or the regular USP (12 lb recoil spring) at slightly more than the g17 (still 30-40 percent faster than the Expert). To illustrate the difference, with the expert, the sights are already on target (or very close) by the time the slide finishes cycling, but with the full size, the front sight is still above the target when the slide returns to battery.

Granted, my splits are not approaching 0.1 so one might argue it makes no difference but I think the extra twentieth of a second gained in slide cycling speed is a slight advantage because it allows confirmation that sights are on target that much faster (therefore initiate trigger press earlier) and has some positive effects for running the gun, eg letting the trigger out and taking up slack almost immediately in the USP lem vs doing it the same way on the expert and occasionally getting a dead trigger.

Despite feeling like I'm being actively held back by the Expert (splits any faster than low twenties seem unattainable, its most comfortable in mid-high twenties), there appears to only be slight improvement in split times switching to the full size (splits in high teens seem theoretically possible, but the gun gets more squirrely when pushing it below mid-twenties).

Because I think it's an issue of slide mass (lighter/SHORTER mass + heavier spring = faster) moving along bore axis, and the shorter slide doesn't carry its momentum as far behind the grip, in this case and others, I would agree that shorter guns seem to shoot flatter. But, I think it's a rare case where there would be measurable and significant improvement in splits from going smaller.

Going from the Expert, which is almost like casting a fishing rod, to the VP9, though, might well be such a case.

[Mr_White]

For me, there is a clear way to compare my results with the different size 9mm Glocks: GSSF. In that venue, which tests aiming, trigger pressing, splits, and transitions on 8" circle targets from 5 to 25 yards, the G34 > G17 > G26. There's no question. My experience may not apply to anyone else. But for me, however all the involved factors add up, if short guns cycle or transition faster than longer guns, it seems clear that whatever the exact nature of that benefit, it is clearly overwhelmed by other factors that are apparently more important. I don't shoot the short guns better.

[YVK]

You don't shoot the small guns better, and neither do I. Or anyone else that I know personally. The question that led to this post was a comparison of almost equally sized guns, with an exception of slightly shorter and lighter slide.
I fully agree with you on large amount of subjectivity in regards to sight tracking, splits and transitions etc. Attempts to objectify fairly similar pistols are hard because the small differences in guns' behavior are often overshadowed by variability in shooter's performance.

Can you convince your GSSF command to let you shoot some HKs for the purposes of uncovering the truth?

[landsharkleather]

I don't think math has anything to do with it. I pretty sure a longer slide means the muzzle is closer to the target so its easier to hit;)

[Mr_White]

You don't shoot the small guns better, and neither do I. Or anyone else that I know personally. The question that led to this post was a comparison of almost equally sized guns, with an exception of slightly shorter and lighter slide.
I fully agree with you on large amount of subjectivity in regards to sight tracking, splits and transitions etc. Attempts to objectify fairly similar pistols are hard because the small differences in guns' behavior are often overshadowed by variability in shooter's performance.

Can you convince your GSSF command to let you shoot some HKs for the purposes of uncovering the truth?

That's true, there are a couple of elements to the discussion. It starts out about sight radius with regard to aiming but the tangents of perceived cyclic speed and target transitions come up in short order too.

It wouldn't be hard to just set up 5 to Glock and do a test.

[45dotACP]

Presumably some shooters tune their recoil springs to specific loads for faster tracking...so there's certainly benefit to faster tracking, but it would appear it's not quite as beneficial as a longer sight radius no?

Sent from my VS876 using Tapatalk

[Surf]

For myself, when speaking about sight radius it is generally when speaking to new or even intermediate shooters and is usually when speaking about pistols vs. rifles. Even many more experienced shooters will note little difference in sight radius in say a G17 to a G34, or G19 to G17 or something similar.

If we take the math provided by Virtuosity Student in a G19 vs. G17, a 1mm (~ 1/32") shift gives almost no noted difference at 7 yards. I will say that at 7 yards I would think that I personally am able to notice as little as a 1mm difference in my sight alignment. So if I think I am able to hold a +/- 1mm deviation in my sights @ 7 yards the results are still .002". I would think that it is virtually impossible for mere mortals to differentiate .002" @ 7 yards and not be able to understand if that margin of error was due to shooter error from shot to shot. Even at 25 yards @ .015" I personally cannot account for that small of an error.

I know I have shooter error margin, which is the bigger issue than the being able to hold say a 1mm deviation static. Yes I understand the compounding effect of the pure math compounded with shooter error or other factors, but man you have to be superhuman at this point. I shoot pistol out to longer distances (~ 200 yds) as a regular part of my routine and it is hard to notice a difference even out to 100 yards on 10" steel from my G19 to my G34. Maybe I need to use smaller targets. I will however be the first to admit that there are guys who are far better marksmen than I am.

[GRV]

I don't doubt the conclusion that longer sight radius leads to less sight deviation, more precision, whatever. I also don't want to come off as attacking or discrediting anyone who's done any math in this thread.

However, this topic has always bugged me because whenever it comes up math starts flying around and no one ever seems to address the real practical concerns in their math. A front sight off by 1mm on a G34 will get a better hit than a G17....great...but my eyes and hands don't decide to take shots when the front sight is off by 1mm transversely....my eyes don't even know what that means when I'm shooting.

Also, when people talk math about sight radius, they always imagine a fixed rear sight and a displaced front sight. Then, when MaxWinsInc. comes out with their latest sights that extend the rear to the back edge of the slide, everyone will talk about how this is awesome because "sight radius". One needs to separately address the issue of how moving the rear further back effects the whole precision thing. Moreover, I imagine there is something to be said about where the actual fulcrum is about which the gun angularly shifts and where the rear sight is in relation to that.


I really don't have time to do the math on this stuff, but if anyone's interested I think a good way to go would be the following:

1) First imagine a rear sight fixed a certain distance in front of the shooter's eye(s), about which the gun will be angled. Now imagine the same front sight at two different distances in front of the rear. For each distance, figure out how much the gun would need to be angled for the front sight to appear to be in the same relative misalignment with the rear. For example, I'd just pick the case where the left edge of the front sight appears to be touching the left edge of the rear notch. We'll call this angle the "misalignment angle".

2) Using the same "appears to be" standard as (1), explore what happens to the misalignment angle for a fixed sight radius when you move the fulcrum around: behind the rear sight, in front of the rear sight.

3) Explore and draw some conclusion about what moving the rear sight rearwards to increase sight radius with a fixed front sight will actually do to the misalignment angle. The results of (1) and (2) might be enough to do this. I haven't thought about it.

There are open parameters here that need to be fixed, like sight widths, arm length, etc. How a particular person misaligns a particular gun is also going to differ. Is it their wrists' fault? Is it their shoulders' fault? What's the grip on that gun like? See point (2). Nevertheless, I think there's some valuable stuff to learn here. At the very least, I think a proper treatment of (1) would be itself a major contribution to the many people who go looking for an explanation of how sight radius helps.

Separately, front-to-back sight size does matter here, but I feel pretty confident that in practice it is negligible enough to ignore and just imagine paper thin sights.

[CCT125US]

Because one thread can never have enough math: https://www.jackweigand.com/Point%20Of%20Impact%20Adjustment%20Formula.html

Another subjective point I noticed was how FS width plays into the perception of height. I had a short lived trial of a Dawson .100 wide by .170 tall FO FS on a P30. My standard setup was a 10-8 RS paired with a Dawson Tritium .125w x .170t FS. This produced POA / POI at 25yds. When I installed the thin FO my shots would impact high. My theory was that I needed more reference than the thin top edge provided, since the sight appeared smaller / shorter, I raised the muzzle slightly. Also based on lighting, I would see the true height on some shots and not on others. Vertical stringing and frustration was the result.