Vision & sight blade width

[InTheBlack]

I think I've now read all the posts dealing with vision, focusing on the target, front sight, in between, changing 'vision' to suit situation, etc.

But no mention of the affect of the front sight blade WIDTH WRT how much 'white space' you see in the rear sight notch.

I started aiming at the wall while cogitating the things I read, and I just realized that my sights have very little white space, which makes it very very hard to pick up the front sight quickly (given my previously mentioned problems).

I think that if my index was perfect, I could just use the rear notch alone.  Might shooot high or low, but the lateral alignment would be there.  Wish I had a sight tool; I could try installing a narrower blade.  This Kimber has a dovetailed front sight... Do they make different widths for it?

I also noted that the serrations on the front sight are only visible when a strong light comes from a particular angle & direction.  So they are not a reliable way to gain a focus on the blade.

The crummy lighting on the indoor range is a worst case scenario too.  But it ought to force me to index!

[benos]

ITB,

In the in-depth book "Competition shooting" by (?) A. L. Yur ev (retired Russian Olympic shooting coach), he details the results of extensive study on that exact question. To nutshell it, you'd like to see, at minimum, a "perceived" (not measured) one-half of the front site's width on each side of the blade. (For my arm's length, my current .115 front and .135 rear is real close.) And, the maximum is considered to be a full front site's width on each side of the blade. Now, these studies relate to International Rapid Fire, where the entire sight picture fits on a huge black target, so it may not correspond to exactly what we do. I've found, however, that it seems to be right on for me. It doesn't really matter how "big" the sites are, your body will naturally attempt to align them a the exact spot you intend. I've found, after MANY experimental sessions, that I CONFIRM perfect alignment much, much quicker with a big, bold, sight picture. With small light bars, the body-mind just spends too much time trying to get them aligned "just right." It's one more of those concepts that goes against our natural instincts.

be

[bountyhunter]

In the black:  most people prefer narrower front blades so they get a better light window.  If you relax eye focus out to the target, a wide front blade will snub out the light bars so you can't see them well.  I like narrower blades with at least 1/2 blade width on either side, a little more gap is better for me.

[triggerpresser]

I am far sighted (see well at distances and have trouble close up), so my sights are a little blurry.  I found that by thinning my front sight, it enabled me to see a light gap on both sides of the front sight.  The blur and fuzz were still there, but now I can center a slightly blurred front sight within the notch of the rear sight.  I had .005" removed from each side on two differant occassions before I was comfortable with it.  You will probably have to experiment with this to see what works for you.

[GMyers]

Does anyone know of someone that makes a narrow from sight specifically with the Kimber dovetail, or is it time to get the file out?

[Phil Dunlop]

I've had a friend with a mill narrow my sights on several occassions. we cut them on the gun (an SV) and have never had a problem.

I'm with BE on the .115" front sight. After my .09 it looked huge, after a bit of practice it looks great.

P.D.

[John Thompson]

Gmyers,

Brownell's got 'em.  When it's gun parts Brownell's has amost everything.

[GMyers]

Thanks John,

A buddy of mine just received the full size "last a year in the outhouse" Brownell's catalog.  I will give it a look see.

[grassy knoll]

is front sight width affected with a fibre optic front sight?  i don't think i could take much off the sight and still have enough to hold the piece of fibre

[InTheBlack]

Come to think of it, Brian etc rub shoulders with the teams sponsored by the major gun manufacturers.  So why not ask them to find out if there is a real reason why each maker uses particular sight blade & notch widths on their production guns, other than "its always been that size & it would cost $$ to change the tooling.""

[TDean]

Got the file out this morning.

I took about .015" off my Dawson fiber-optic front post.  It's now at .120" with the rear Bo-Mar notch at .138"

The "light bars" on either side of the front post are perfect (1/2 the thickness of the post) at my arms length (6'-1" wingspan)

A little Brownells 444 blueing liquid, and it looks like one of 'dem perfessionawls did't !

[munitor]

I've searched the literature on this a bit and also asked a human factors engineer about it.

According to the human factors engineer, for fast alignment, you need to see enough light at each side that the bit of wobble you have doesn't pinch out the light significantly. He was unsure about the vertical, but thought patridge was probably best. His comment on the dot front was wondering how the dot would be indexed against the rear sight unless it had dots, too, and in the same apparent position. I told him on precision shots one would use the top of the front sight and he said he thought the dot would make people shoot high if they were in a hurry (is this true?).

The Russian shooting coach BE mentions, A. A. Yer'yev, also reported that the most winning rear sight in the various Olympic pistol shooting events, by 2 to 1, had a U shaped notch, not a square bottomed notch (that makes the "half ghost ring" over 40 years old).

The Russians found that a front sight that was the same or slightly wider than the apparent width of the bullseye gives the best accuracy with the least eye fatigue, but because Olympic pistol targets have a wide bullseye, they found that rule impractical to implement for pistols. Instead, they settled on a front sight, 0.125-0.145 wide, which their experience has shown to give maximum accuracy and minimum eye fatigue.

A quick calc shows an 6" plate at 50 yds would be about the visible width of a 0.093 front sight (with sight 28" from eye). An 8" plate at 50 yds would equal a 0.124 front sight at 28".

I run a 0.145 rear notch and recently narrowed my front sight from 0.125 to 0.097, which I have found much easier to see with my aging eyes. From the looks of it I am running at the 1:3 end of the scale rather than the 1:2. Given all this, maybe I should have opened up the rear notch, instead. Might be worth a try, but I am probably already in the ballpark.

[Phil Dunlop]

Munitor,

I'd like to add another aspect for your concideration, I hope my description is not too confusing;

I've typically used a front/rear sight ratio of about .8, previously a .09" front and .112" rear, now I'm trying Brians recipie, which is a little tighter at .85

The idea of an acceptable sight picture, as opposed to a perfect one has been discussed.

I think it becomes progressively harder to judge the adequacy of a sight picture at high speed as that ratio declines.

With my old sight picture, just seeing the front post through the rear results in an A out to 12 yards (laterally that is, the worst vertical error through the rear notch would score a low C/D on a Classic target)

For me that is a major concideration and it makes shooting much faster

P.D.

[munitor]

Phil, you're right - I got a bit confused (not an unusual condition for me!).

You described your previous sight setup as .090/.112, which is a calculated 0.80 and approximately a visual  0.46 (or 2.2:1 if we use the apparent rear to front ratio like the Russians do).  That gives you a bit more than half a front blade's width on each side. If I understand you right, you also said this setup gave you an A out to 12 yds (laterally). You also said you are now using Brian's setup, which is 0.115/0.135, or 0.85 calculated, 0.49 visually (2.04:1 Russian ratio). All this seems straightforward.

Then you said "I think it becomes progressively harder to judge the adequacy of a sight picture at high speed as that ratio declines." That's where you lost me. Did you mean it was harder with your old sight picture than your new one, or vice versa?

I agree with you that it really helps to know just how far off you are when the blade is at the edge of the notch, and at what distances that is acceptable.

[InTheBlack]

Why don't one of you machinists make up and sell an aluminum "slide" with holes, and a series of front blades and rear notches of different widths, so they can be just dropped into the holes (held in with cotter pins from below, then we could use it in motion).  A simple "grip" held on with a nut & bolt, so the user could adjust the angle to match his guns.  Clubs could use them, & gun stores could sell more sights.

I want one free for coming up with the idea.

[Phil Dunlop]

Munitor,

just seeing the blade within the notch with your sight picture (.67 ratio) is less likely to result in an A hit than the tighter sight picture I described.

Its a trade off, I'm sure yours would be faster to align, but mine requires less aligning

Its only my opinion, but it is something to concider when choosing a sight picture, obviously the conditions vary conciderably in IPSC unlike ISSF/UIT.

I also have  rapid fire gun, though I haven't shot it seriously yet, i did start to adjust the sight picture towards a more typical IPSC set up. As it came the front post pretty much filed the rear notch

P.D.

[munitor]

Phil, you are right in that a front sight that fills more of the rear notch allows less deviation than one with more white space, but I think what the Russians (and the human factors engineer I talked to) were saying is that the eye can't confirm how much deviation there is unless it can see white space on both sides of the blade, and that in the Russian's experience you need a .85 to .67 setup to do that quickly enough to win a gold medal in Olympic rapid fire. All the configurations we have been discussing fit that range so I view them as simply within the spectrum of individual preference or physical difference.

When I use my new sight setup I can almost always see some white space unless my index is way off. I am learning to see what I need to see with the new sight setup, and its a little different than what I used to use. But for me its easier to use and faster than the old one. I just know that for an A at 12 yds I need a bit of white all around. I am finding that easier to achieve than if the front sight has pinched out the light on one side, which it often did with the old setup (and my aging eyes).

[Phil Dunlop]

Good luck with that set up, I might try it or similar next time I feel like a change,

P.D.

[DogmaDog]

Yeah, this is pretty late, but,

Dangit!  I've been looking for sights allowing more light through for my Kimber (0.110 front, 0.114 rear) and my Kahr (0.142 front, 0.152 rear).

It looks like EVERYBODY knows that there should be more of a difference, yet the sights came that way, and when I call about replacements, Heinie, Bo-mar, Novak, all tell me their replacements have "about the same sight picture as the factory sights".  WTF!!!  With an M-16, that front sight is floating in an OCEAN of space surrounded by the rear aperture, but eyes can still center it.

It's not like it really would be harder to cut a larger notch.  

Guess I'll have to go get a file.  What sort would you recommend (as far a coarseness)?

Thanks for letting me vent,

DogmaDog

[Joe]

I'll add my recent experience also.

I widened the factory fixed 3-dot rear notch on my Commander from .125 to .150, keeping the front at .125.  This has given me a very fast sight alignment.  I did the rear notch because it was the easiest to modify.  I took a flat file and ground flat one of the edges so I wouldn't change the depth of the notch.  I did one side at a time, measuring the width often so as to remove the same amount from each side.  This kept the windage from changing.

I'm still able to keep all of my rounds in an 8 inch circle at 25yrds and somewhat consistantly hit bowling pins at 40+.

Remember I'm still a BEginner but I recently did a 7yrd Bill Drill that had 2 targets side by side, one being inverted, six rounds each w/a mag change between in just over 9 seconds with all A's.  I'm also shooting a lot more A's than C's in our regular COF.

Thanks again for the Great Forums.

Joe

[kaiserb]

Another option, and one that I used.  Rather than file the front sight narrower, I bought a rear sight that has a wider gap.  When I focus on the front sight I can see a decent gap to center up with however when I focus out on the target and let the sights blur I get a solid black when I am lined up perfect.  It took me a while to find the right combo, I really think the gap size is a personal decision, based on your grip, the gun etc.

[TDean]

I'm using a .075" front and a standard .110" rear notch. That puts me at .68 ratio.

Pretty low by most standards it seems, but I love it.

[rhino]

You guys are the first group I've seen that narrow the front specifically to get more light on either side. The reason I narrow the front sight is so it won't obscure as much of the target at 25 anf 50 yards.

For focusing on the front sight, I wonder if the smallest ghost ring/aperture rear might help. I suggest this because when you switch apertures on an AR, the front sight post and/or a red dot will always look sharper and more in focus when you use the smaller aperture.

[Loves2Shoot]

I got convinced to go to a wider front sight last year and I (for whatever reason) pick it up faster, I still have a thin sight on my single stack and it works fine but I shoot tighter groups with the wider FS. Don't know if it makes a "real" difference, I've tried 5 front sights and they all seem to do the job.

[Kevin Kline]

TDean,

That is so ironic you say that. When I was working my way up and made GM in Limited and shooting my best, I was shooting my STI with a .070 front and standard .110 (I believe) rear Bomar. I loved it and felt very fast with it. I must have been doing fairly well cause I made GM with it. I'm sure shooting my STI made some difference also.

I took a break from shooting and concentrated on work (LEO/SWAT) for about 1-2 years and shot more tactically with work related exercises. About6 months ago, I got back into IPSC shooting and have been playing in Production with my Glock. I really like it and have tried different sight setups, but havent found one I really like as much as my .070 front. It's funny you say that, because I was thinking about narrowing my front sight from the .095 it is now back to .070 on my Glock and seeing what happens. Also, I've been shooting with both eyes open instead of one eye closed. I'm actually more accurate and have much less trigger jerking with both eyes open and I'm much more visual. I also starting to get faster with as I get used to both eyes.