Rangeball

I have a red dot sight on my shotgun. It has a 4 MOA dot, meaning when centered on a target 100 yards away, it appears to cover a 4" circle on the target.

Anyone know how much area of a target 30 yards away a .03 sight pin viewed 30" from your eye would appear to cover?

Jeepnut

I don' t know how practical this is, but I just turned this into a basic math problem. As an engineer, I always have to draw out a diagram to help figure these things out. So on the left side of the diagram we have a single point (the eye). 30" to the right there is an obstruction (pin) of .03" . We' ll assume you' re shooting horizontal to the ground to simplify things. Since you' re pin is centered perfectly we' ll draw half of the obstruction above the horizontal line and half below. Now you have a triangle shown from the eye to the top of the pin, down to the horizontal line, and back to the eye. Now, since you can' t see through the pin, we' ll extend that sloping line from the eye to the top of the pin, to the target 1018" (30 yards) away.

Basically, it works out to a simple geometry problem. According to this method, a .03 pin, held 30" from your eye, will cover an area of 1.1" at 30 yards.

Rangeball

I thought that' d be how you' d do it, but had no idea of the math involved

Only question still remaining is is the .03 inches or some other measurement? Is a " large" sight pin of .03 really only 3/100 of an inch? Seems pretty small...

BobCo19-65

wow, I alway thought it would be a bit more then that. I use .019" pins and would have though that it covers about a 2" area. But I guess that you have to take the " halo" effect around the fiber optic pin into consideration also. I don' t think that I actually see .019 when the fiber optic pin is lit up like a lightbulb. Seems there maybe a case for the old brass pins that I used to use.

Rack-attack

I just scaled it out on AUOTCAD and I agree with jeep - mathematically it is about 1.1"

But I do not know how the eye may focus this though. I know that light crosses over through the lense and this may effect it.

it does seem larger

There is also a halo effect that may cause it to seem larger.

Good question though[8D]

Jeepnut

I was going to figure it out in AutoCAD but that seemed like cheating. So I blew the dust off my calculator & did it the old fashion way. (There' s a guy here who still has a slide rule so I guess it' s not that old fasion.)

I think the halo affect will definitely make it seem larger. If a .03 pin appears to be twice it' s size due to the halo, then the blocked area will double to about 2" . But who knows how big the pin actually looks to the eye.

I prefer a smaller .019 pin just because it suits my eye better but I' ve never really given any thought to the area that' s blocked out. I know you' re supposed to " aim small, miss small" . Maybe I' m not aiming small enough but I don' t think I' ve ever noticed that 1 or 2 inches of the target is blocked from view.

I used to work with a guy who won a lot of local 3-D tournaments and he always used the small brass pins. He said that the fiber optic pins blocked too much of the target. Apparently he knew what he was talking about.

Rangeball

It seems like fiber optic pins came about because a lot of guys were having trouble seeing the small brass pins through their peeps in low light. Since I' ve gone peepless (no-peep), I wonder if I would have this problem? If not, the brass pin would certainly give one a smaller aiming/concentration point without the halo effect...

Hmmmmmm...

BobCo19-65

I think that I keep my .019 fiber optic pins for the hunting sights, cause I don' t shoot past 30 yards anyway, but I may try a few brass pins for the 40 and 50 yard pin. I only shoot during the day, so I don' t think the low light will be a problem.

Jeepnut

So where can a person find brass pins? I know I' ve seen them in the past but it' s been a while. Seems like all you can find these days is the fiber optic.

Rangeball

I' m just screwed. I shoot a savage pendulum with their flag pins, they don' t offer anything except fiber, in .029...