Target dimensioning

I am not sure how the NRA does it, but the basic rule is that a 6" target at 600 yards is the same as a 1" target at 100 yards

Except it isn't.

1 MOA at 100 yards is actually 1.047 " (really though, if you can shoot that well, you wouldn't need me to tell you about this )

errors are not prone to a linear increase with increased range- that is a 1' miss at 100 yards might be 3 inches at 200 yards- or paradoxically, it might be 1' at 200 yards.

The other issue is that at 25 yards, the hole in the paper will be more than 1 MOA if you are using .223.

Me, I?

For 25 yards I'd use NRA smallbore 50 foot targets

(which I just tryed to Google, and found they don't seem to exist anymore, but some sells these:
http://www.bonanza.com/listings/Vintage-NRA-Official-50-Ft-Small-Bore-Rifle-Targets-12/23505111 )

The NRA targets are scaled assuming you are using a .30 cal bullet, that's why the 100yd rings are less than half the size of the 200yd rings.

This is because of the way targets are scored. Since a shot that merely touches the line counts, the 3" X ring on the SR target is "hit" by any .30 cal bullets that strike within a 3.3" circle. Thus, when we look at the SR1 target, the 1.35" X ring is hit by any shots within a 1.65" circle (or 1/2 of 3.3").

To boil it all down though, you can halve the size of a target by reducing the size of the rings by half and then further reducing them by half the diameter of the bullet. The numbers would be slightly different when you try scaling targets by a factor other than 1/2, but hopefully this makes sense?

Excerpt from a post:
"While I don't compensate for bullet size I believe sight picture of aiming black is maintained. I don't think splitting hairs on aiming ring is that beneficial in terms of developing as a shooter."

http://www.thehighroad.org/showthread.php?t=649919

Just use a linear ratio, that will get you pretty close.

So if you had a 600 yard target that you want to shoot at 300 yards:

600-yard-target-diameter * 300 / 600 = 300-yard-target-diameter.

You can do a linear reduction and score based on the center of the hole instead of the edge.

Or
1) take the radius of each ring at 600y, ADD 1 bullet radius
2) scale that linearly
3) the subtract 1 bullet radius to each ring at your new close distance, and score by touching edge.

The X ring can come out negative for very close distances, so just use a pinpoint if thats the case. (FWIW, the X ring on a 50ft NRA Smallbore target is a pin point)

I'm in the process of hacking together a simulated NRA highpower target myself. I looked up the width of their bullseyes, grabbed an image of said bullseye off images.google.com, and began running the math. What I got was

to simulate 200 yards at 25 yards make the bullseye 4.63 inches.

to simulate 300 yards at 25 yards make the bullseye 3.08 inches.

to simulate 500 yards at 25 yards make the bullseye 1.8 inches.

to simulate 600 yards at 25 yards make the bullseye 2.5 inches.

The NRA site I was going off of had the 600 yard bullseye at 60 inches wide whereas the 500 yard and under were 37 inches wide, hence why the 600 yard one is bigger at 25 yards than the 500 yard target.

I mostly shoot 22LR, so I've got a bunch of simulated range 25m targets worked up that you can just print and use. The highpower simulation is my newest one, still a bit of a work in project.

The ring size on NRA reduced targets were adjusted so that shooters would shoot the same score short range, that they would long range.

That is why the MOA measurements are not in line with the full scale targets.

For 25 yards I'd use NRA smallbore 50 foot targets

(which I just tryed to Google, and found they don't seem to exist anymore, but some sells these:
http://www.bonanza.com/listings/Vint...ts-12/23505111 )

Click to expand...

The smallbore club right by my house has piles and piles of 50 foot NRA targets.

Looks good! Think you could post an image of the finished target so we can all try it?

I like it, I'll print some out and bring them to the range Saturday.

When I was hacking together my 25 yard highpower simulation I went off

http://www.nrahq.org/compete/RuleBooks/HPR/hpr-w04.pdf

for the target dimensions and found the attached image on Google to use. Attached is my admittedly very rough draft which is to be posted at 25 yards. (I added the second 500 yard prone target at the bottom of page 1 because my prone needs a lot of work.)

Isn't this just simple math? I wanted a target at which to dry fire in my shop that would "look like" the 100 yd. targets at which we shoot at our High Power matches. Since we only aim at the black, (not the other scoring rings) take the diameter of the black on the SR-1 target (6.35"), divide it by 300', and your target should be .0211" per foot of distance. Since I dry fire at a distance of 17' I taped a manilla folder to a storage cabinet and drew a black circle about 3/8" in diameter at which to aim.
At 25 yds. (75') your black circle would need to be a hair over 1.5" in diameter. I wouldn't worry with scoring rings at such short distances because by the time you get a simulated 600 yd. target, the rings would be so close together that your shots would likely hit more than one ring.

I recently built a 200 yd. steel target for practicing offhand (200 yd. Fun!!). I happened to have some 22" diameter pieces of 3/8" steel laying around so I used them. this allowed me a 13" aiming black (X, 10 & 9-rings), the 8-ring and part of the 7-ring. Lots of fun to shoot at.

A couple of years ago I built a 600 yd. target and all I made was the 36" aiming black:






Point is, if a guy shoots good loads, sights his rifle in properly, and can call his shots, the aiming black is really all that matters with the possible exception of offhand shooting.

35W

MD, Your rings are slightly too big because you're not factoring in how scoring is done and the radius of the bullet. If you want to be precise, its not as simple as just scaling the ring sizes by 25/200.

For a .223, to duplicate a 25y target from that 200y target, your ring sizes should be X-.28", 10-.78", 9-1.53", 8-2.28", 7-3.03", 6-3.78", 5-4.53" to get the same end-score.

So your X ring is off by +35%, or about 1/10".

On that gong target, is there a risk that the bullet could ricochet back to the shooter? Or does the fact that it's hanging eliminate that?

mainecoon said:

On that gong target, is there a risk that the bullet could ricochet back to the shooter? Or does the fact that it's hanging eliminate that?

Click to expand...

Absolutely not. Both the 200 and 600 yd gongs disintegrate the bullets. The only exception is on the 600 yd. gong. I've fired at it with GP-11 out of my Swiss K-31 and most of them actually go through the gong which is 1/4" or so diamond plate. Everything else flattens and drops to the ground. I also have a 3/4" x 6" swinger at 100 yds. that likewise destroys the bullets.

35W