# My DIY Rangefinder



## Maui Rhino (Mar 13, 2010)

Slipping along the hillside, I followed a game trail through a forest of native Hawaiian Ohi’a Lehua and Koa trees in search of a monster billy goat. Hunting at about 6700’ elevation, I was inside a thin cloud which limited visibility to about 50 yards. Peeking over a small ripple in the volcanic terrain, I quickly spotted a medium-sized billy grazing in a small clearing. I guesstimated that he was about 35 yards away. Slowly raising my Nikon Archers Choice, I hit the range button and got back a reading of 3 yards. From past experience, I knew what the problem was….Water droplets in the air from the cloud were scattering the laser beam, rendering my rangefinder useless. Luckily, this was not a billy that I wanted to shoot. 

I can’t begin to count the number of arrows I have lost over the years due to this scenario. I see a goat, try to range it, and my rangefinder is useless because I am in a cloud. I take a guess that he is 30 yards away and let fly, only to see my arrow drop under his belly or go over his back because I am off by a few yards.

Many years ago, I read that in the average encounter with an animal, you will have six seconds from when you see an animal to knock an arrow, estimate the range, draw back, anchor, and take the shot. My spot-n-stalk hunts have certainly proved this true. On almost every hunt, I have an encounter or two where I slip over a ridge and spot a goat at the same time they see me. They will stare at me for a few seconds, before they start to take off. If I try take the time to range him, he won’t stick around long enough to give me a shot, or he moves a few yards while I am drawing, and I am back to guessing the range. 

For years I have seen ads in the bowhunting magazines for the Dead-On Rangefinder, and I have been tempted many times to buy one. For those of you who have never heard of it, the way it works is that there is a mark on one side of your sight housing. You place that mark at the belly of your target animal, and look to see where the back line falls. Above the belly mark are more marks that correspond to the height of the average target animal of your species at a given range. According to Dead-On’s advertising, it is adjustable for any species. And at $20, it is not very expensive. However, I enjoy making and using my own gear, so I had to give this a try. 

First I did some research. According to Dead-On’s website, the average whitetail is 17 inches from belly to back, and the average Pronghorn is 14 inches. However, they are not what I am usually hunting. Feral goats tend to run smaller. My first step was to bring a tape measure and notebook with me while hunting. Over the course of a year or so, I measured the back to belly distance of over a dozen goats that my friends or I shot. The biggest billies were about 13” wide, and the smallest dinks were about 11”. Averaging it out, I decided to make mine based on a 12” measurement. 

Next, I collected the parts I would need. An old broken 3-pin sight furnished three lengths of fiber optic. This would allow me to set up 20 and 30 yard marks on my sight. As a bonus, I could even match the color of my 20 and 30 yard pins. A hot-glue gun, a fine point sharpie, a ruler, and some blue painters tape rounded out the gear I would need. 

First, I hot-glued the belly marker inside my sight housing at about the 8 o’clock position. Heading out to my backyard range, I placed a 12 inch long piece of blue painters tape on my bag target. Stepping back to the 20yd line, I held my bow out as if shooting. With the bottom of the tape at the belly mark, I used a fine point sharpie marker to mark the housing at the top of the line. Then I repeated the process for the 30yd line. It was a little tricky to both hold the bow and mark the sight housing accurately, but not too bad. 

Back inside the garage, I hot-glued the 20 and 30yd markers in place. During this step, I was careful to make sure that the 3 pins ran parallel to each other, and that when I held the bow out, I only saw the ends of the pins, and not a short line from viewing the pins on an angle. Again, it sounds harder than it was. When finished, this is what I had. First, from the shooter’s view:



And from the front of the bow, showing more of the inside of the sight housing:



Once done, it was time to put it to the test. Back at the bag target, the pins lined up perfectly with the tape at the 20 and 30 yard lines. The pins were not the brightest, but I could clearly see them in daylight. As the sun began to set, I realized that I could also use the outline of the pin inside the housing to get my range, even if I could not see the color of the fiber optic. Top pin to top pin (20 yards) and second pin down to second pin down for 30 yards. If I had more fiber optic, I would have made a 40yd pin as well. However, since this is a backup RF for me, and I still plan to use my Nikon when ever I can, this will do for now. I can always add one later. 

Now back to the hunt I opened this with. The billy I was watching soon fed his way up the gully he was in, and I continued across to the next ridge. Peeking over the top, I saw the back of a small goat grazing about 20 yards away in a gully slightly below me. Backing up a few steps, I dropped my pack and knocked an arrow. After a few deep breaths, I again crept forward, looking for something to kill. 

When I got to where I had just seen the goat, he was not visible. Inching forward, more of the gully became visible as I continued scanning. Still nothing, so I inched up a little more. Suddenly, I heard the hated warning cough! Instantly, a handful of goats began running uphill into view, a nice billy at the rear of the pack. As they ran, I drew and swung my bow along with the billy in one motion. Finding the billy in my sight, I noted that his back fit nicely between the two top pins on my DIY rangefinder. Almost without conscious thought, I centered him between my 20 and 30 yard pins, and a heartbeat later, when he paused to look around, the arrow was gone. 

In a flash, the arrow crossed the distance between us and passed through the billy in the sweet spot. He ran a few yards up the gulch and disappeared around a corner. A moment later, I heard him cross to the other side of the gulch, and he came back into view as he climbed a ledge. As I watched, he tried to leap up anther ledge, but his legs failed him, and he tumbled about 10 feet to the bottom. After a few more kicks, he was done. It had only been a few seconds from when I first saw him as he ran. I don’t think I could have taken this billy without my DIY rangefinder.


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## CamoCop (May 19, 2009)

great story and goat! that is a good idea but seems like alot of work. i just bought a rangefinder instead...lol


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## snort742 (Jan 5, 2008)

You could have used your pins to do the same thing


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## oldschoolcj5 (Jun 8, 2009)

great story and goat - way to DIY a Dead-on!


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## OrangeBlood (Jan 12, 2009)

sounds pretty cool, good job man


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## Maui Rhino (Mar 13, 2010)

Thanks for all the comments. I have and still use my rangefinder, and this is just a back-up. It is very common on my hunts to be inside a cloud (fog) where a RF is useless. Also, for those quick shots, I now have a ready means of judging the range. It really wasn't a lot of work to build. Once I measured several goats, I had the information I needed to calibrate it for my target species--feral goats. If you are hunting most common N. American critters, their chest measurements are posted on the Dead-On website.


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## Maine Iceman (May 30, 2012)

I think that this is a great idea for fixed pin sights. Range finders are great if you can get to them quickly and quietly enough and they have working batteries and it is in sunny enough weather etc. etc. etc. This is quick and reliable for the shooter and the bow is already in a shooting position to measure distance unlike when one has to drop their bow arm to point an RF. Very Innovative. Congrats.


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## Pittstate23 (Dec 27, 2010)

interesting


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## Stevie777 (May 2, 2013)

That's what i love about any hobby/sport. You can use your napper to make just about anything that does as good a job as the stuff we can readily buy.

For me that's the challenge, so far i've made a Arrow square from a broken arrow, cost..two nocks and some glue, A fletching jig from a piece of 3x2, two clothes pegs and a hacksaw blade, cost, around £3. 
Wrist slings and bow slings, cost..around £6, Target, cost, one empty potato chip box and a read out of old clothes from my wardrobe.
The real beauty of DIY/Adapt and overcome for me is when people ask me what project i'm working on now.
As none of my friend know one end or a Bow from another it's pointless me trying to describe what i'm up to now, so I dont tell them until i finish the project. tis fun.

Well done OP.

Another of my DIY efforts, least said about this one the better though...lol
http://www.archerytalk.com/vb/showthread.php?t=2236123


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## Maui Rhino (Mar 13, 2010)

As a follow-up to this, the hot glue lasted several hunts before I lost one of the fiber optics. Reglued them using 5 minute epoxy, and they have held up well. Still loving my DIY rangefinder for those times when rain or fog prevents the laser rangefinder from working, or when I just don't have enough time to use it.


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