What sized target fills a Nikon BDC circle at the different yardages?

[Special T]

So I just got back from a prairie dog shoot near Burns OR, and my bro in law and cousin both have the Nikon coyote special on top of identical R15 shooting 223. How big a steel circle do i need to make for our long range practice out at the bro in laws farm? I think he has an 8" steel that is close but its too thin and blow though it closer than 300yrd... I have a 12" 1.5 in thick circle but want to know if i need a larger one or need to trim it down? I tried looking for info n the Nikon site and her and came up with nothing.. Thanks!

[uplandhunter870]

this is what i found off the nikon sight. im not sure what unit of measure they use to measure the crosshair wire, but having a couple BDC recticles myself i really want to say they used mm in the pic.

hopefully once you figure out what units they use someone with better math skills than i can help extrapolate how big of a plate you need for each ring, also notice they only give the circle dia. on the 9 power

[Special T]

thanks that's a start!

[Ridgeratt]

do a google search on first focal plane and it will help explain it

[Heredoggydoggy]

Depends on the magnificaion setting of the scope.  The size of the reticle circles stays the same, but the size of the target varies according to the magnification setting.

[Special T]

I bring up this old thread because im continuing to do research on this scope. I contacted Nikon and they sent me in PDF form the 2016 SRO Catalog. In it it has all the pertinent information regarding their retacales. T image Upland posted is the measurements in inches at 100 yards on 9 power. They are also the same numbers for the 4.5x14  @ 100 yards at full power. Since this seems to  be a MOA measurement system then all the same rules would apply correct?

Is there a mathematical way to calculate what the sizes would be on 3 power? I keep putting a few pieces of the pie together and eventually ill have it figured out!

[lokidog]

Wouldn't the circle cover 3X the area that it does at 9X?  The target will be smaller at lower magnification.

So, let's say a 9" circle is covered at 9 power, change it to 3X and it would cover a 27" circle.

[Special T]

Ive done some informal measuring. @ 100 yards i believe the Big Circle "C" is 8" on 3 power 5" & 2" for the smaller circles. This is just some rough measurements  that i did from a bench with sand bags to steady the scope... I believe there is at least 1" error possible.

[Remnar]

tag

[Special T]

I have  scope that changes retical size but not drop so I understand the difference. If I cannot find some way to do the math ill just continue to do it the hard way with known shapes and sizes intil I build a dope card.

[BULLBLASTER]

If the su tensions are on 9 power they may not be exactly tripled on 3 power. Do you have Nikon spot on app on your smart phone? That will handle all the math for you and you can mess with it. Other than that I would spend some time at 95-96 yards with a gun vice or led sled and 1 inch graph paper. 1 moa equals 1 inch somehwere between 95 and 96 yards. Play with it at all powers and figure out the size in moa of the circles and wrote it down, also spacing of the circles in moa.

[bman940]

Excellent question and I can say in 6 years it is the first time I have heard it. The coyote special scope is not made for target shooting but for getting on fur and making the shot. One of my favorite scopes for fast target acquisition. The sub-tension's listed in the earier thread are indeed for 9X magnification. Unfortunately I'm not sure what they woould change to at lower magnification using the second focal plance scope. I will try to find out the answer and get back to you. That being said, it would be easy to make steel target's to fit what we know to be true with the 9X subtension's.Even at 100 yards most folks are going to use max magnification and getting used to getting on target and sending a round might be more productive then filling the circle with metal. Spot On will show you the differences in distance if you turn turn your scope to a lower magnification as I am showing below.

[Special T]

I seem to toss up on moving coyotes on 3 power because of the eye relief. The size of the circle does in fact change at 3 power. Ive written my estimations down and will continue to do so. Im mostly thinking of the quicker offhand shots and figured there had to be some way to figure it out mathematically instead of the thumb nail sketch. I have played with the spot on site and love it for the drop, so there has to be a way to do the same thing with the change in circle size.

[bman940]

It is 3X more. Example, The subtension's triple at 3 x over the stated MOA at 9X. 1 MOA at 9X becomes 3MOA at 3X, add 300 yards to that and the subtension of the circle cover's 9 inches.  I'f you want to make steel target's I'd go with 12 inch steel plates and practice getting on them quickly. I hope this helps out?

[Special T]

It is 3X more. Example, The subtension's triple at 3 x over the stated MOA at 9X. 1 MOA at 9X becomes 3MOA at 3X, add 300 yards to that and the subtension of the circle cover's 9 inches.  I'f you want to make steel target's I'd go with 12 inch steel plates and practice getting on them quickly. I hope this helps out?

So id the main circle is 3" @9power then it should be 9"@3power by your math.this is fairly close to my observed 8"