Measure distance for a backyard range

[saskuach]

Hi

I searched and couldn't find anywhere on how to measure out a range. I have a large yard that would work for shooting, but I would like to know what at what range I'm shooting at

So what methods do you recommend/use? Rope, pacing? That's all I could think of. It doesn't need to be very accurate, and longest would be up to maybe 500 yards.

[capbuster]

You might measure your stride and see if it is close to 36". If so, you can use one step as one yard and measure your distances by walking to your target.

[Archie]

Most hardware stores have 50 foot measuring tapes. You have to measure and stake and measure and stake, but it works. Another hardware store possiblity are those 'wheel thingies' that measure as you roll them along. However, these two methods will measure irregularities in the terrain, and you may not want that.

See if there is a rental agency around you that will rent a transit. Those surveyor's telescope doohickeys? Read the directions and you can lay out your 100, 200, 300, 500, 600 and 1,000 yard markers. You need an assistant to do it easily. If you must, call a surveyor and see what they would charge you to do the plotting.

See if the internet has any aerial photos of your property. Figure out the scale and you can calculate how far away is "that tree", "this fenceline", "that ridgeline" and the "big rock on top of the mound".

You might try a combination of idea one and idea three. That would get you close, at least.

[bastiat]

Laser range finder?

[saskuach]

Hey, "one of those wheel things" is *not* a bad idea at all... but pricey. For that price I might look at a rangefinder, but I blew my budget on my gun.

I also tried the aerial photo and that looks like it'll work really well. I found some especially good reference points in my yard.

I might combine some of these methods to confirm and/or refine the measurements but I definitely have a better idea of the ranges at least.

@bastiat: If I would have one, I'd use it Good idea though.

Thanks for all the input.

[mummac]

GPS?

[STEVE M]

If all else fails an USGA map and a compass. If your nav. skills are up to it, you can get very close. The maps only run a few bucks.

[BillCA]

Of course, we are all presuming that there are no neighbors, structures or roadways behind your home for at least 1 mile. That's one of the advantages of "country living" if you're in a suitable area.

Best check with your local city or county agencies before you commence firing too!

[Archie]

(It only hurt for a couple minutes...)

Requires three people, two rifles with 'decent' scopes, and two arrangements to 'sand bag' rifles in place. Walkie-talkies would be helpful. Make sure all the guns are empty and so forth; be sure everyone involved are 'friends'.

Sand bag rifle number one in place, pointing down range, at extreme right edge of proposed firing line. Very important, this rifle must be at 90 degree angle to firing line.

Sand bag rifle number two in place at extreme left end of firing line. Make sure the butt of rifle number two is on the same line as the butt of rifle on that 90 degree angle to the firing line.

Surveying guys do this with transits, which are very similar to telescopic rifle sights, but without rifles. My plan here is done cheap, assuming you have access to two rifles with 'scopes.

Person number three is a very trusting sort. He is holding a marker stick down range. His stick has to be directly downrange from rifle number one.

If you've done this right, you've created a "right triangle", defined by the two rifles and the brave lad with the marker stick.

Carefully measure the distance between the two rifles. You know rifle number marks a 90 degree angle. You have to measure the angle of rifle two to the firing line. Knowing two angles and the length of one side of a triangle will allow you to calculate the length of the third angle (which really doesn't matter to us in this case) and the lengths of the other two sides of the triangle, which is the point of this whole thing.

The distance between rifle number one and rifle number two (the firing line width) is the "adjacent" side of the triangle. The distance from rifle number one to the marking stick is the "opposite" side; this is the range from firing line to target. The distance from rifle number two to the stick is the hypotenuse.

Don't you wish you paid more attention in High School?

What you really want to do is to preset the angles of both rifles and the firing line length. Then the intersection of where the two scopes are pointing will be what ever range you want.

We'll say you have a range 50 feet wide and you want a 100 yard target distance, okay? So you have a triangle with a 50 foot adjacent side hooked to a 300 foot (100 yards) opposite side by a 90 degree angle, right?
What you really need to know is what angle to set rifle number two in order for both rifles to be pointing at the same place at 100 yards.

You can do this a couple ways.

One. Draw this out on paper to scale. Draw a right triangle with the short side equal to 50, the middle side equal to 300 and connected by a 90 degree angle. Measure the angle of the short side to the hypotenuse (the longest side) and write that down.

Two. Calculate it.
The tangent of the angle in question is equal to dividing the opposite by the adjacent, or 300 divided by 50; or 6. Checking a 'trig table' (do a websearch) gives an angle of 80.5 degrees. (This is only if the firing line is 50 feet wide, remember.) Setting up rifle two at exactly 80.5 degrees is going to be tedious, too.

Set up your two rifles and have your brave stickman walk out and then you two guys with the scopes wave him back and forth until the stick is lined up in the zero of both rifles. (This is where the walkie-talkies would be handy.)

This may be more math work than you want to do. But it will not fail as long as you measure and calculate properly.

Maybe you can find a surveyor who is a shooter and trade him some range time?

[K80Geoff]

Oh come on!!! Everybody has a roll up measuring tape, unless you are a shut in geek living with your mother in a major urban area.


Jeez, like this is so difficult. Don't need any hypotenuses and right angles, just a tape and some wood stakes. Pound stake at firing line, hook tape end to stake, walk out to end of tape in the direction of your backstop. When tape reaches end (say 25 feet). pound in stake and repeat untill you reach the desired distance. You may have to do some rudimentary third grade math (three feet equals 1 yard etc)

I have one of those wheel thingies for my business. They are not that accurate over rough ground.

I would be worrying more about local ordinances and noise problems with cranky neighbors than how to measure distance.

[novus collectus]

I like Archie's way best and if your use K80Geoff's way you have your 50,100,150 yrd markers already laid out too. Archie's way is too complicated if you are by yourself. Do this, place a gong to fire at about where you think the range is, fire your rifle at it and wait for the report. Time the time it takes for the sound to come back and at 1000-1100 ft/s you know that one second is a 1000 yards. Of course you have to calculate the humidity, atmospheric pressure and temperature to know just how fast the speed of sound is at that moment. You can make your own barometer by using a closed end on a bent tube filled with water (the right graduations take a little trial and error and this will take a few years). You can also make you own hygrometer. Of course you have to be reeaaal quick with your stopwatch ti measue less than 500 yds though.

[saskuach]

Archie, I've tried triangulation before, but never with a rifle scope. I was trying to measure the distance of a radio tower, but the technique was really rough. Was probably off by hundreds of yards. I would actually do this, but I only have one scope.

Thanks Geoff, but I can't measure across the roof of the pro-jects. And my mom won't let me rappel from my window in my ninja gear. sorry...