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Reduced distance air rifle targets

Posted: Sat Jan 30, 2010 2:49 pm
by Shooterer
I am looking to find information on what the ring sizes would be for shooting at 21 feet (that is all the room I have to practice).

If someone could direct me to a site, or has the information I would appreciate it. I do the same thing for my HP shooting and Ray-Vin has a spread sheet on their site that all you have to do is enter the distance you are shooting at and it will give you all the calculations (ie: at 21’ the black of the target I shoot at for the 200yd stage is 5/8”)

Thanks,
Jim

Posted: Sat Jan 30, 2010 3:17 pm
by jmkwyo
should be a simple conversion... take the size of your air rifle target's 'black' and the distance and put it as a ratio on the other side you can solve for the 'x' or 'black's size'....

33.3ft/(size of air rifle bull) x 21ft/(size of new bull) solve for the size of new bull... either that or just draw a black mark down range and slowly make it larger until it is the right size...

Posted: Sat Jan 30, 2010 8:05 pm
by Shooterer
Thanks jmkwyo for the concept, but I think you may have it backwards. It should be the aiming black/33.3x21= reduced size. (1.375/33.3'=.0413x21'=.867)

If someone could please share the scoring ring sizes, I could make up a reducing spreadsheet that I would share with everyone.

Attached is the practice target I use for HighPower matches the black aiming circle is 12"@200, 18"@300 and 36"@600yds, but is 5/8"@21'

Jim

Image

Posted: Sun Jan 31, 2010 11:48 am
by caveman
Shooterer,
I came up with something different. Using simple cross multplication (distance you are using) times (standard bull size) divided by (standard distance) = 21' * 1.195" / 33.3' = 0.753" or 3/4"

Note: Unless you change your front and rear apetures in the same proportion the sight picture is going to be quite different than the standard target at standard distance.

Posted: Sun Jan 31, 2010 6:03 pm
by jmkwyo
That's what I said!

Posted: Mon Feb 01, 2010 1:17 pm
by Guest
jmkwyo,
Sorry, I must have miss read your post.

Caveman,
I used a different bull size.

To anyone that knows,
What are the sizes of the scoring rings?

Thanks
Jim

Posted: Mon Feb 01, 2010 1:44 pm
by Guest
It would seem that you are firing at reduced distance as a practice/training exercise. If so, you may find it easier to purchase targets printed for a distance that approximates what you have available and simply train on those. For example, an AR-4 (5 meter) or TQ-5 (25 foot) target may meet your needs at cost below printing scaled targets from your own computer.

Posted: Wed Feb 03, 2010 10:44 am
by jmkwyo

Posted: Fri Feb 05, 2010 10:25 pm
by Ed-WI
Cool guys!
Thanks
Ed

Posted: Sat Feb 06, 2010 12:03 pm
by paulo
Have you tried to download the Scatt software http://www.scatt.com/software.htm after you install, under tools there is an option for "print target" once you open the application pick the target of your choice, then "SCATT solution 10 meters" and then enter the distance in your case 21 feet = 6.4008 meter.
For NRA targets you can find more options here http://centershot.com/ once you unzip files just copy them to the target folder of the software.

Scoring on reduced size targets

Posted: Mon Feb 08, 2010 11:56 am
by ishoottrap
Scoring on reduced size targets can not be done correctly by linearly scaling the scoring rings by the ratio of standard to reduced distance. The reason this is true is that the size of the projectile does not scale. Here's an example:

The size of the 8 ring on a standard 10m air rifle target is 10.5mm in diameter or 5.25mm radius. At 10 meters, a shot that is centered squarely on the ring has an angular error of of 1.89 seconds.

Shooting at a distance of 5 meters with the same angular error results in a shot centered 2.625mm from the center of the target and the innermost portion of the hole is only .375mm from the center of the target. Since the 9 ring on the scaled target is 5.5mm in diameter, 2.25 mm in radius, this shot would score a 9 at the reduced yardage which is incorrect.

I developed a set of macros for generating archery targets for reduced distance practice and in that case, I allowed entering the diameter of the arrow being used and then generated a second set of lines which result in correct scoring, these are drawn as thin dashed lines inside the linearly scaled lines. I did this so that the sight picture would remain correct yet proper scoring could be established. With air rifle, the projectile is so large compared to the target that this results in a very cluttered target so I left them off.

Best Regards,

-Scot

Posted: Mon Feb 08, 2010 12:51 pm
by GaryN
When I made reduced range targets, I used the HighNoon excel spreadsheet to compute the ring diameters adjusting for pellet size.
BUT I made the BLACK bull in scale w/o pellet size compensation. This is the only thing I can see from the firing line, so that was the only thing I needed to scale for visual only.
The problem when using the Pellant target program is I have to use one ring for the BLACK, so from that ring outward, I cannot number the ring, as the number would be off by 1, and I loose the outermost ring.