Post by: ivarhusa on May 02, 2009, 02:23:04 PM
What would you say is a typical/average distance across a coyote, front legs to back legs? I am looking for a way of estimating (until a range finder gets purchased) how far a coyote is from me, based on how it looks in my crosshairs.
Out at the rifle range, I determined that the distance between the thickness changes in my duplex reticule covered exactly (well pretty darn close to) 6" at 100 yards, when dialed in at maximum magnification (in my case, 12x).
Here is what I expect to see at "some distance" away:
(https://hunting-washington.com/smf/proxy.php?request=http%3A%2F%2Fpages.pocketinet.com%2F%7Eivar%2Fphotos%2FCoyoteProfileCrossHair.JPG&hash=acf09d0cd2fbea3572e720fd1417d239e7da2254)
Note that I am trying to show (in my crude sketch) that the transition from thick to thin (both sides) exactly spans the "wheelbase" of this coyote.
If I take the wheelbase of a coyote to be 24", when you do the math, that would place this coyote at exactly 400 yards (6"/100yds=24"/ X, solve for X). Is 24" a good estimate for this distance?
Observing that a coyote in profile doesn't fill the space between the reticule changes is a sign that the coyote is at least 400 yds away.
What do you think of this approach? I fully expect that others have done something like this already, making this idea not all that original. Have you done this for coyotes? I recall an old Redfield scope that had "brisket" lines, and a post in view, that would read ranges out on deer-size critters. That was sort-of my inspiration.
(I was reluctant to include head and tail in "picking a width", because of the variations in the way they are "held" by a critter (up, down, turned).
Ivar
PS and sorry I am :'( not to be looking at an in-the-flesh coyote, and making this measurement myself. I was headed hunting this morning, but the rain discouraged me (and LastCat).
Post by: clindsayrun on May 02, 2009, 03:36:41 PM
I just wanted to point out that this seems to be a really intelligent way of determining range. I don't think that I ever would have thought of this...but now that you've put it out there I'm going to look into it.
Post by: runamuk on May 02, 2009, 03:50:34 PM
just my suggestions... and I like your idea.... I also need a range finder :P
Post by: jjhunter on May 02, 2009, 04:32:00 PM
Post by: ivarhusa on May 02, 2009, 04:51:38 PM
My first surmise would be about 16".
Using that number, a coyote whose "chest depth" spanned the "full reticule" would be 266 yds away (6"/100yds=16"/ X yds). That is a pretty useful number, and could be used to augment an estimate based on "wheelbase".
Ivar
Post by: DOUBLELUNG on May 02, 2009, 04:55:15 PM
I think the depth of a coyote's chest is a much better ranging/hold-over reference. I have used it for years with great success.....same thing with deer. :twocents:I agree. However, since I had a cased pelt here, I measured it - 19.5" wheelbase. Probably a little shrinkage when tanned, I think 20" would work as a guestimator.
I have a Burris fixed six on my go-to .30-06. It subtends 18" duplex to duplex at 165 yards, and duplex to intersection of the crosshairs at 330 yards. I used that for years to determine that if a mule deer buck's brisket depth subtended at least from the duplex tip to the intersection, I was good to go to hold dead-on (i.e., less than 330 yards range). About 5 years back, I found a Bushnell Yardage Pro 800 rangefinder someone had left on a hillside in WY, so now I use that - but I don't think I would ever have bought one for rifle hunting big game.
Post by: JoshT on May 02, 2009, 05:02:32 PM
I think the depth of a coyote's chest is a much better ranging/hold-over reference. I have used it for years with great success.....same thing with deer. :twocents:
I've found that 12" gives pretty good results here (that's fur to fur... they're much smaller than that if it's actuall back to brisket)... I used this system with my Leupold for years... it was 3" from the center to the point on the duplex... if a coyote fit... it was 400 yards. This system wasn't fool proof... but it worked pretty well. And, if I sighted my rifle in about 1"-1.5" high, depending on cal., the point of the duplex was pretty close at 400... so it was a good system all-around.
Post by: jjhunter on May 02, 2009, 05:29:45 PM
Post by: Bofire on May 02, 2009, 06:59:13 PM
Carl
Post by: ivarhusa on May 02, 2009, 07:03:40 PM
For my rifle, then, were the coyote subtend the full vertical extent of the duplex reticule, it would be 200 yds away. Similarly, if it subtends half that (from crosshair to reticule), that would be 400 yds. That is a long ways away.
Quite by coincidence, my rifle has a 12" drop at 400 yds (zeroed at 250 yds). This is serendipitous, in that for a 400 yd shot, I would put the duplex thickness transition at my intended impact location. Sweet!
Here is about what my sight picture would be at 400yds.
(https://hunting-washington.com/smf/proxy.php?request=http%3A%2F%2Fpages.pocketinet.com%2F%7Eivar%2Fphotos%2FCoyoteProfile400ydshot.JPG&hash=9e6deed36f28ab0652de7f415c51371adb3e4df4)
The center of the crosshair is at the very top of the image, in my attempt to show this 'to scale'. The distance from the 'duplex point' to the center is intended to equal the brisket depth of the coyote.
Ivar
PS The coyote image was not 'mine'. I borrowed it form the web.
Post by: uncoolperson on May 02, 2009, 11:22:38 PM
Post by: JoshT on May 02, 2009, 11:35:23 PM
OK, guys. I think I will agree that 12" is a better number for this purpose.
For my rifle, then, were the coyote subtend the full vertical extent of the duplex reticule, it would be 200 yds away. Similarly, if it subtends half that (from crosshair to reticule), that would be 400 yds. That is a long ways away.
Quite by coincidence, my rifle has a 12" drop at 400 yds (zeroed at 250 yds). This is serendipitous, in that for a 400 yd shot, I would put the duplex thickness transition at my intended impact location. Sweet!
"The beauty of the plan is in its simplicity dude" -Walter Sobchak