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OnTarget Software
Free Program Measures and Calculates Shot Groups

Jeffrey Block has created a great new FREE software program, OnTarget, that measures shot groups quickly and precisely. All you need is a photo or scan of your target. The program allows you to set your target distance, and provides caliber-specific tools to precisely mark the center of each shot. Once you've marked each bullet hole, Jeff's OnTarget program automatically calculates group center, maximum group spread (CTC), average distance to center, group width and height, and group offset from point of aim. The program will even measure multiple groups on the same target.


After just a few minutes spent learning the program's tool buttons, we were able to plot shot groups on a variety of targets with ease. Once you select the target distance and bullet diameter, figuring group size is a simple matter of centering a circle tool over each bullet hole. Then the program "connects the dots" and provides all the info you could want automatically. A text block (which can be moved anywhere on the screen) summarizes all the key data.

The program worked with bullet holes as small as 17 caliber and as large as 50 caliber. It is very precise, but remember that if your target photo was taken at an angle, distorted perspective can cause slight errors in measurement. Therefore, for the ultimate precision, you want to start with a flat scan of the target. OnTarget communicates easily with most scanners. Forum member Bob Spencer reports: "[OnTarget] is easy to use, well documented, and it interfaces very well with my HP scanner."


OnTarget Compared to Measuring Manually
Forum Member Scott Armbruster recently downloaded and used OnTarget. Here's his review: "Excellent tool, extremely user friendly, and fast. I measured a five-shot group manually with dial calipers and then used OnTarget and was within .005 of an inch. The .005 was probably my error. The best part of the program is that it is accurate and free."

We found OnTarget to be especially useful for groups with widely dispersed bullet holes, or very small bullet holes, such as 17 caliber holes. It can be very difficult to measure 17-cal group sizes with a standard caliper, because the tool itself obscures the tiny holes. With OnTarget, the program can zoom up your target view, making it much easier to plot the center of each shot. And with a widely dispersed group of shots, the program automatically finds the two most distant shots. You can't mistakenly pick the wrong pair of shots to measure.

OnTarget also works great when you're plotting a large number of shots that overlap. Because you can zoom the target image 500% or more, you can see fine details, allowing you to plot shots that would othewise be "lost in the clutter". The program also calculates average shot distance from center (ATC). This is very useful for score shooters who need to "hold center" on the 10-Ring (see below).

Flash Tutorial Shows How It Works
Jeff created an excellent animated Flash tutorial demonstrating OnTarget's functions. It shows how to import a target image or scan, how to set target distance and scale, how to set bullet size and circle each bullet hole, and how to save the marked and measured target.



Here are examples we created with OnTarget. The first photo shows a 17 Mach 2 target with five bullet holes, two overlapping. These tiny 17-cal holes are notoriously hard to measure. With OnTarget, it's a snap. You just load the target image into the program, zoom in with the controls, and then click on the center of the holes. The program automatically calculates group size, displaying measurements in both inches and minutes of angle (MOA).

Original Target (with ruler for scale)

Target Captured and Displayed in Program

10-shot Groups? -- No Problem
Here's another target, showing 6mm bullet holes at 600 yards. The first image shows the target image loaded into the program with the ten holes circled in red.

Target Displayed in Program

For this target we have used the Aiming Point option. The Aim Point was set at the center of the "X" and the program calculates average distance from the Aim Point. Very cool.

Detail of 10-Shot Group, Enlarged by Program

OnTarget Options and PowerUser Tips

Though OnTarget has good instructions, some of the fine points of the program are not obvious. Here are some tips:

1. Once you've set a circle around a bullet hole, it's there for good. You cannot delete the circle around the hole. If you made a mistake, you need to delete the group and start over again.

2. You can change line color and thickness by going to Tools > Options > Drawing Options. Colors change immediately. However, if you choose a thicker line width, the line may not appear wider until you zoom the target image 300% or more.

3. The white Text Information Block can be re-positioned if you select Tools > Options and then click "Moveable Group Text". To actually move the text you need to LEFT CLICK in the upper left hand corner of the white Text Field. A "Text" icon will pop up and you can move it to the new position with your mouse.

4. If you use a target photo, rather than a scan, you'll need a reference measurement to set scale. This needs to be a true dimension, such as width of a target grid, or the diameter of a coin photographed on the target. The longer the reference dimension, the more accurate the scale will be. To set the reference, click the button with two blue "X"s connected by a diagonal line.

5. You can plot multiple groups on the same target. Just click the "New Group" button or select "Tools > New Group" each time you want to add a group. To switch between measured groups, use the pull-down menu at top right.

No Scanner Needed
The OnTarget program grabs target scans directly from a flatbed scanner using Microsoft's Windows Image Acquisition system. But don't worry if you don't have a scanner. You can just take a digital photo of your target and OnTarget will import it quickly and easily. To set target scale, a simple tool allows you to mark a known length on the target (such as the diameter of the "X" Ring), and the program will then size the target accordingly.

Save Target as Image File (JPEG, PNG, TIFF, BMP)
When you've finished plotting a target, you can save it as an OnTarget file with a ".TGX" extension. That lets you later re-size or edit the Target. In addition, you can save your target, complete with bullet outlines, group plots, and descriptive text, as an ordinary JPEG, PNG, or BMP image file. This way you can view the target with any image program. And you can upload the target to display on a website or internet forum. Just select "File" then "Save View as Graphic".

Bottom Line -- Great Program, Download It!
Jeffrey Block has done a great service for shooters by creating the FREE OnTarget program. It is easy to learn, it functions great, and it can save you time and effort measuring targets. It also lets you easily archive and compare multiple targets produced during load development or rifle testing. You can record ammo type, date, location, weather etc. in note fields accessed by "Group Info" and "Target Info" tabs (shown at right).

Keep in mind that OnTarget was NOT created to replace existing methods for scoring competition targets. There are specialized tools with caliber-specific optics that can measure benchrest targets with great precision. But for all other target measuring purposes it does a great job. You should visit OnTargetShooting.com, view the tutorial, and give it a try yourself.

Review by Mr. Moderator

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