Dry fire practice at shorter distance with reduced size targets

[douglaswlloyd]

Hello,

I'm new to this forum, but have shot CMP matches for about 5 years.

I would like to do some realistic dry fire practice during this winter, but cannot manage the 200 yard distance between me and the target on my property.

My question is this: How much smaller should the standard 200yd target be to present the same sight picture at 100 yards? How about other distances?

If someone has already worked this out or there is a conversion chart please forward me this.

thanks,
Doug

 

[Howard Roark]

All you need to do is print out a series of periods of progressivly larger sizes untill it looks right for the distance you have to dry fire.
. . . . .
Make the next line bigger and so on.

Here is a link to reduced targets in pdf.
http://ray-vin.com/frtech.htm

You can dry fire at any distance. 10' is as good as 200 yards if the target size is correct.

 

[Tn Tom]

I can fix you up

Mr Doug,
I thought sure I had the SR targets saved in PDF format but dang if I can find them.
On page 14 of the NRA Rulebook you find all the dimensions if you want to draw your own. In the mean time Ill find the site for the downloads.
Tom

try this its got what your looking for
http://dotclue.org/targets

 

[cdrt]

You might try using the 50 yard slow fire target (B6) that is used in Bullseye (NRA Conventional Pistol) at 100 yards. I've used it with my M1 and it takes the same sight elevation that I use for the std 200 yard target.

 

[ocabj]

The size of the aiming black on an SR target (200 yard target High Power) is 13 inches. You can figure out the correct reduced size of a target for a specific distance using simple math.

The way you are supposed to calculate a reduced target is using MOA, or minutes of angle.

The formula that correlates the relationship of MOA to the size/length/diameter of a given target is:

One common example explaining MOA in terms of inches is the size of 1MOA at 100 yards, such that 1MOA / 60 is the angle in degrees:

So, in order to find the size of the aiming black on the SR target, you simply adjust the formula used to calculate the size of a target based on a given MOA to instead find the unknown, which in this case is MOA.

Now that we know 13" at 200 yards is 6.207036036 MOA you can use that value to create the appropriate sized aiming black for the distance you will be practing your dry firing at. To test this value, we can cross check it against 100 yards (since the reduced SR target for 100 yards has an aiming black of 6.5 inches; 200 yard aiming black of 13 inches divided by 2).

So 6.207036036 MOA is correct.

 

[ocabj]

So as a follow up, let's say you are going to practice inside the house and you are going to stand 20 feet away from the wall where you will put up a black aiming dot.

Since you know the size of the aiming black must be 6.207036036 MOA for whatever distance you are from the target, simply plug that into the equation using 20 feet as your distance:

tan (6.207036036 / 60) * 20 feet * 12 (inches per foot) = .4333333333~ inches

Thus, for the proper size target at 20 feet away, the black circle should be .4333333333~ inches.

Simple.

 

[douglaswlloyd]

Awesome! This is just what I needed. Thanks Jonathon!

This article ought to be written up as a permanent tip and stored somewhere handy for other novice shooters.

Doug

 

[fractal7]

Simplified Rule

So I thought of this question on my own just tonight and came to the same conclusion but with a simpler formula:

(Full Size Target Size)/(Distance to Full Size Target) X (New Distance to Target) = (Reduced Target Size)

Just make sure everything is in the same units (inches is probably easiest) and you don't need to mess with tangents and what not...any simple calculator will work.

So for the example above you end up with

(13 inches)/(7200 inches) X (240 inches) = 0.4333 inches.

Hope this helps.

 

[Offfhand]

Doug, you got some really good and thoughtful information to your question. It's not often that questions such as yours are answered with such effort and foresight, especially on websites. (Does anyone wonder why the gun industry professionals laugh when the shooting/gun sites are mentioned?) My hat is off to all respondents with admiration, and as for myself all I can say is dry firing is the surest way to better scores. Good luck to you next season.

 

[Sunray]

Dry firing is about practicing trigger control, sight picture and breathing. All you need is an aming point. A door knob at the end of a hall way makes a good aiming point.

 

[P-32]

If you are going to stand off about 20 feet in the house, a black tack works.

 

[Lovesbeer99]

There is no reason to figure anything out. NRA has defined targets already.
I'm not sure of all the specific numbers, (SR, B8, SR42, etc) but they already have a 200 yard, 300 yard, and 600 yard target reduced for 100 yard practice.

If you want you can check the small bore rules for 50 ft targets and air rifle has 15ft and 33 ft targets.

Check NRA, and if that doesn't work try one of the NRA approved target suppliers.

 

[skidooman603]

For indoor dryfire I have taken a 50ft small bore target and reduced by half for my 25 ft distance. Works for me

 

[Bovice]

fractal7 nailed it. You don't need to go using MOA and trig functions. Like he said, you just need to set up a proportion.

(target length at original distance)/(original distance)=(target length at new distance)/(new distance)

your unknown component would be the target length at the new distance, which can be solved for by cross-multiplying. You can then obtain the width by finding out what the original width is and scaling it down by the same factor as the length.

middle school mathematics FTW