Iron and Free shooters, north of Expert - Need your input

I've read Nygord, Yur yev and others mention the popular front/rear ratio as either 1:1:1 or 1:2:1.
I am assuming that this is "perceived" ratio and not actual measured ratio.  Correct?
If so, then when I trig it out, I get, for example with the 1:2:1 ratio sight set, a rear notch that should be .190.
Maybe you are all widening out your rear notches and I've just never asked but all of the current and older Bomar rears come with much narrower rear notches.  I just bought a genuine Bomar BMCX for a wad gun I'm having built and it's notch is .112.
If the ratios are NOT perceived but actual, then the rear notch is even wider.
I put my front on a surface grinder and took it down to .112 which looks pretty good to me but is still far shy of 1:2:1 with my unmodified rear and is not the preferred way to get there anyway as I want the blade's perceived width to be close to the average width of the 25 and 50 bulls so it really needs to stay at about .125 and the rear should be widened.
Were all you guys opening up your rear notches or just ignoring the recommended relationships and leafing the rear at the original .112-.125 width?

Comments please?
Thanks,
Ed


FYI, to match the bull diameter, the front width when shooting at 50, would need to be .154 and at 25 yds it would need to be .214 so you definitely wouldn't want to get this ratio by narrowing the front.  It is already too skinny.

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I'm of the opinion it's a perceived ratio not specifically measured. Free is typically shot at one distance so choosing front sight width and rear sight notch width is fairly simple with older Toz style blades of newer adj notches. I think its difficult to replicate on a Bomar rear sight. The rear blade is not very wide. I've seen Toz blades adapted and believe its the best way to go if your serious about iron sights and using a Bomar. Front sights wider than .125 are probably impossible to find for a 1911 without custom fab'ing something. So potentially usning a 1911 optic rail adapted with euro sights is the hot ticket.
Jon

PM sent Jon.

What is your current classification? Either NRA or USAS. Not sure about exact ratios but I would offer the following:

For Free, l would not concern myself about sights but focus ( pardon the pun) on hold and a smooth trigger release. I had a few 546s indoors this year and staying close to that .450 diameter 50 foot 10 ring is heavily biased for good hold. I shoot a TOZ as it came.

Too narrow a rear, like in many Smith revolvers can cause eye strain. Too wide is a less common issue but your subconscious brain can still center it well. Intl RF shooters go for very wide rears in the interest of speed.

For me the clarity is more important than the ratio.  If the "bars of white" are too small, they can become fuzzy or slightly blurred do the narrow width for the light to come through.  That causes the loss of a crisp clean vertical edge on the front sight.  If the "bars of white" are too large, it becomes more difficult to notice how well centered the front sight is in the notch.

So, basically I don't worry about the ratio, but generally file the front sight to get crisp, clean "bars of white" depending on the rear notch.  I've found it easier to keep the front sight width even and parallel when working on it than when filing on the rear sight notch. And sometimes just changing the front sight is whole lot easier overall.   An "un-square" rear sight notch (width of bars of white varying from bottom to top) just drives me to distraction and I'm not that good with a file and don't have ready access to machine shop.

CR

I put my Gold Cup on the surface grinder at lunch today, dressed a wheel to .165 and widened the rear.  Instant improvement during dryfiring tonight so I know I'm on the right track.  Much less eye strain and the front still seems to float in the middle with no loss of precision. I would just prefer a replaceable rear blade for the new Bomar rear that I am sending to the guy who is building my new iron sighted wad / EIC gun.

First off you need to clearly see the front sight.  Vision acuity, age, lighting come into play here. 
If you need numbers, the time tested High Standard 107 Victor sight rear notch is .106 wide, .102 deep, and the front sight .121 wide.  Sight radius is 8 5/8

A Giles HS sight rail has rear notch .115 wide, .092 deep, front sight is .125 wide.  Radius 8 5/8. 

1963 made Gold Cup rear sight width .118, .067 deep, front .126 wide.  Radius 6 7/16.

Time tested numbers.

I don't know the measurements of my sights, but every factory open sight I've looked through is too tight. The rear notch has to be opened. Maybe it's my long arms. Maybe it's my wobble. I don't know, but pretty much every stock sight has tiny slivers of light on the sides. I MUCH prefer enough room that the front sight never disappears. If the front sight is visible within the rear sight, great, I know where it is. If it disappears behind one of the sides, I can't tell if it's a little bit out or a lot out, until it gets so far out that it is obvious on the opposite side.

I used a safe edge file to open my sights. The file was a cheap piece of... and the "safe" edge wasn't perfect, so the bottom is a little rounded, but if I'm annoyed by the imperfection, it means my focus is in the right place.