How do you determine the correct front Aperture Sight insert size?

[travisimel]

How do you determine the correct front Aperture Sight insert size?
Is there a formula to determine the correct size?
The smallest aperture in my set is 3.2 and it seems much too large.
My daughter is shooting a CZ 452 Scout. It is a small rifle that the Eye-to-Front Sight distance is only 24” inches.
She is Shooting A17 NRA targets at 50 Feet.

 

[Jim Watson]

You (she) should see a substantial white ring around the target black so as to give a sight picture with three clear concentric circles, target, front aperture, rear aperture.
Many folks size their front aperture too small.

What front sight do you have?
Champion's Choice has Anschutz inserts down to 2.5mm.
http://www.champchoice.com/prod-ANSCHUTZ_METAL_APERTURES__SIZE___2_5___4_5_-3819.aspx

And sets of the clear inserts in two sizes, apertures down to 2.2
http://www.champchoice.com/prod-CHAMPION_S_CHOICE_CLEAR_INSERT_SET__10___Sm_Dia_-677.aspx

http://www.champchoice.com/prod-CHAMPIONS__CHOICE_CLEAR_INSERT_SET__10___Lg_Dia_-690.aspx

Or call them up, they are helpful.

 

[Howard Roark]

The front aperture should be at least three times the width of the bull. In other words, there should be a line of white equal to the diameter of the black bullseye all the way around the bull.

Don't let her get into the trap of thinking that a smaller line (circle) of white will allow more precise aiming. I won't. It only amplifies the perception of movement and the resulting muscle contractions to correct for it, bad.

The eye is good at centering objects, let it.

 

[Hangingrock]

http://fuzzylimey.net/projects/targapert.html

 

[35 Whelen]

read this: Sight Alignment, Trigger Control and the Big Lie. It's from Jar Head Top and it's a few chapters out of his book. Super good reading. He states to use a large front aperture and a small, or better yet, adjustable rear aperture.

35W

 

[travisimel]

Thanks for all the help.

Thanks for all the help.
She settled in with a 2.7 and shot well.
Her scores were 427 out of 500 on A17 Targets in practice at our range, and a 389 in competition last weekend in Grand Junction, great for an eight year old, in a new range.

 

[35 Whelen]

Many, many congratulations to her! I bet you're proud of her.
35W

 

[Jim Watson]

Great outcome.
But here we have another case of Cute Tax being due.

 

[kd7nqb]

GREAT PICTURE I don't have kids yet but I can honestly say that I believe if you get to the point where that picture exists you did something right as a father. Most pictures of an 8yr old today involve an XBOX and a bag of chips.

 

[culpeper99]

http://www.myculpeper.com/aperturesize/Determine small bore rifle front aperture size.htm

 

[Grump]

All these charts and measurements and math...

I just went with a hole between 1.5 and 2 times the apparent width of the bull. Closer to 2x worked best.

I loved those clear ones with the black marked cone shaped hole. Wish I could find 'em again. And my metal inserts for the Olympic front sight...

 

[Soupy44]

My rule for beginners is to have the front aperture big enough that part of the bull stays inside the aperture at all times. As you get better, this changes over to all of the bull is inside the aperture at all times.

 

[culpeper99]

I agree with Grump. Shooting is the best method. Nevertheless, there is still a methodology involved in it. I'm just curious if the chart is reasonable or not.