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Pthfndr
07-06-2007, 6:00 PM
How good are you with it?
Do you use it with a Mildot Master?
Do you know how to calculate it?

Would you bet money on your ability to do it?

Given 10 targets, and their approximate size (+/- a couple inches), at distances from 80 to 600 yards, could you range them using your scope to within +/- 10 yards within 10 minutes?

I found out recently I could do it about 90% of the time. Quite honestly, even after practicing it a lot I was surprised I did that well. It's also a lot easier (for me) using a TMR than Mildot.

And before anyone says they'd just use a LRF, I'm not talking about using a LRF, just your scope.

rg_1111@yahoo.com
07-06-2007, 6:06 PM
I just wish i was as good as you.
Thats great.

HK_Fan
07-06-2007, 6:23 PM
I just wish i was as good as you.
Thats great.
I sense some self astem issues here....lol

PistolPete75
07-06-2007, 6:38 PM
I will soon when i get my .308 back from dros with my upcoming range finder Leupold RX-IV Rangfinder and mildot master.

And I'll be doing it the old fashioned way with a regular mildot.

rg_1111@yahoo.com
07-06-2007, 7:28 PM
I just started shooting long range rifle for one. That's over 100 yards.
I have been shooting at 100 and less for a long time.
Next is i dont have a mildot scope with a range finder.
I will get a range finder on my next scope. LOL..


Quote:
Originally Posted by rg_1111@yahoo.com
I just wish i was as good as you.
Thats great.

I sense some self astem issues here....lol

Timberwolf
07-06-2007, 8:00 PM
I use a mildot scope and mildot master but am adapt to using a good old fashion calculator or just plain pen and paper for the math. 10 UKDs with known size target in 10 mins, +/- 10 yards . . . haven't tested myself in a longwhile though when I'm setting up COFs for my matches if my LRF isn't handy I'll mil the target and generally when I go back and check with my LRF I 'm pretty damn close.

phish
07-06-2007, 8:20 PM
TMR = tactical milling reticle?

Pthfndr
07-06-2007, 8:44 PM
TMR = tactical milling reticle?

Yep

Pthfndr
07-06-2007, 8:48 PM
I use a mildot scope and mildot master but am adapt to using a good old fashion calculator or just plain pen and paper for the math. 10 UKDs with known size target in 10 mins, +/- 10 yards . . . haven't tested myself in a longwhile though when I'm setting up COFs for my matches if my LRF isn't handy I'll mil the target and generally when I go back and check with my LRF I 'm pretty damn close.


I'd never done it under pressure until the big Norcal match. I'm getting better at it. When I go out in the hills I range stuff and then LRF it to confirm.

You're shooting the the SCPRC tomorrow aren't you? Good Luck.

dwh100
07-06-2007, 8:53 PM
Practice with this:

http://www.shooterready.com/lrsdemolow.html

Paratus et Vigilans
07-06-2007, 8:59 PM
Try one of the Leatherwood Auto-ranging scopes. M-600 for AR-15 and M-1200 for AR-10 .308 Win. They do it mechanically with an external cam that shifts the tube up and down a subtle amount in a cradle you mount to your flattop. It's a setup they call a "cam-puter," and it works based on a setting you select for the bullet you're loading together with a distance estimate based on the size of the target as determined from scales etched in the glass of the scope. Basically, you use the etched marks to zoom to the proper size estimate of the target, and that automatically shifts the tube as you zoom, so you can then hold the crosshairs dead on target. I've got an M-600 on my SPR build that works great, and I plan to put an M-1200 on my .308 POF/DPMS build when I get my act together and order up the parts from CWS.

Or do it all in your head, if you're quick enough at the calcs. :D I'm not, so I got a scope that does the heavy lifting for me.

glockman19
07-06-2007, 9:09 PM
Yes I think I can. I have a 6-24x40 scope with a mil-dot recticle. I have had success out to 500 yards on a 18" target. I am shooting with an M1A loaded with bedded stock and 147/150 & 165 grain bullets ranging from Winchester to Federal.

I do have a cheat sheet(s) that I laminated. It is a table of mils for objects in feet & inches. You also have to know the trajectory of your ammo.

1 mil = 3.6" @ 100 yards
1 foot = 2.8 mil @ 100 yards

For example a 147 grain .308/7.62 will be about even at 50 yards, high 1.9" at 100 yards, dead on at 209 yards, low by 8" @ 300 yards, low by 23" @ 400 yards and low by 48" @ 500 yards.

The calculation is:
Height of item in yards (meters) x 1000/Mils read = Distance to item in yards (meters)

Bring your calculator

TMC
07-06-2007, 9:20 PM
Yes I think I can. I have a 6-24x40 scope with a mil-dot recticle. I have had success out to 500 yards on a 18" target. I am shooting with an M1A loaded with bedded stock and 147/150 & 165 grain bullets ranging from Winchester to Federal.

I do have a cheat sheet(s) that I laminated. It is a table of mils for objects in feet & inches. You also have to know the trajectory of your ammo.

1 mil = 3.6" @ 100 yards
1 foot = 2.8 mil @ 100 yards

For example a 147 grain .308/7.62 will be about even at 50 yards, high 1.9" at 100 yards, dead on at 209 yards, low by 8" @ 300 yards, low by 23" @ 400 yards and low by 48" @ 500 yards.

The calculation is:
Height of item in yards (meters) x 1000/Mils read = Distance to item in yards (meters)

Bring your calculator

You seem to be basing this on know distances, it seems to me he is asking if you can use your scope to find the range and hit a known target size (i.e. human torso which many military scopes with built in ranging use) at unknown distances.

I can hit most targets with my TA11 if I know the range, I don't know how to find the range of a trget with my scope.

Technical Ted
07-06-2007, 9:35 PM
I've got the basic theory down, but I don't get to practice at +100yds often enough.

mprahm
07-06-2007, 9:53 PM
Just got a USOptics with a MOA reticle should be able to range find soon enough with the .308 I'm taking it out next weekend to test. MOA reticles are fairly easy especialy since its FFP

Pthfndr
07-06-2007, 10:04 PM
You seem to be basing this on know distances, it seems to me he is asking if you can use your scope to find the range and hit a known target size (i.e. human torso which many military scopes with built in ranging use) at unknown distances.

Exactly.

At the recent Nor Cal Tactical Bolt Rifle Challenge held at the Sac Valley range, 75% of the competitors correctly ranged only 50% or less of the targets. We were given the size of the targets before hand. All we had to do was accurately mil them, and then either do the math or use something like a mil dot master to figure the range. Some of the targets were partially obscured so that only the head was visible in the grass.

The closest target was only 88 yards away. The furthest was around 600. I was told one competitor swore the farthest target was at least 1000 yards.

Lots of things come into play when ranging with a scope. A big one is making sure your scope is set to the correct magnification for ranging! You need to know what size your target is. If there is a lot of mirage, it makes milling the target accurately more difficult because the edges might not be well defined. You need to be able to hold steady. You need to know what size mil dots you have (USMC oval or Army round), or how thick you mil lines are.

If you are correct to within +/- 10 yards out to 600 yards you're pretty much guaranteed some kind of hit on a torso sized target. But if you're 1/4 mil off when you range it, you'll miss.

One thing that's really satisfying for me, is to range a target with the scope, check my range card and either adjust for elevation - or even better, the hold over - and get a first round hit. It's just another skill to put in my marksmanship bag.

DJDace
07-07-2007, 12:04 AM
This is what I need to figure out with my IOR scope. What the correct magnification is for ranging with the IOR MP8 reticle.

Accurate ranging with my scope is one of the skills I really want to focus on in my precision shooting.

glockman19
07-07-2007, 8:09 AM
Pthfndr,
I you didn't read very well or assumed something incorrectly. By knowing the size of an object:
1 mil = 3.6" @ 100 yards
1 foot = 2.8 mil @ 100 yards
It is very easy to calculate distance.
Height of item in yards (meters) x 1000/Mils read = Distance to item in yards (meters)

That's all there is to it.

Pthfndr
07-07-2007, 6:12 PM
Pthfndr,
I you didn't read very well or assumed something incorrectly. By knowing the size of an object:

It is very easy to calculate distance.


That's all there is to it.

I didn't misread or assume anything. I wasn't disputing or argueing about anything you posted.

Yes, those equations you posted are correct.

I guess I'm missing your point.

Why don't you give an example.

Mute
07-07-2007, 6:55 PM
Hard targets with easily viewed outlines I do quite well out to 700 on UKD. Pretty close to 100%. With targets like 3d dears and things that don't have such defined outlines it's a little harder but if I concentrate I can still do it more than 90% of the time. I usually confirm, after ranging, with a laser range finder.

My tools are usually a mil-dot master and a simple calculator. The GAP Mil reticle with the half mil hash marks helps a great deal. I find it much more effective than either the army or marine style mildots, even the Gen 2 ones from Premier Reticles.

glockman19
07-07-2007, 9:43 PM
Why don't you give an example.
I did.

1 mil = 3.6" @ 100 yards
1 foot = 2.8 mil @ 100 yards

Estimating the height of the object you're aiming at can be calculated in to distance by the number of Mil's. Once again for those who didn't get it the first time:
Height of item in inches x 27.8 (25.4)/Mils read = Distance to target in yards (meters).

Target = man = 6' or 72" = 5 mil, 72" x 27.8 = 2001.6 / 5 mils = 400.3 yards
with a 150 grain .308 I'd aim 24" high to compensate for balisitics drop.

Same target man = 5'9" = 4 mil, 69" x 27.8 = 1918.2 / 4 mils = 479 yards
with a 150 grain .308 I'd aim 48" high to compensate for balisitics drop.

Same target man = 5'9" = 10 mil, 69" x 27.8 = 1918.2 / 10 mils = 191.82 yards.
with a 150 grain .308 I'd aim dead center on the cross hairs as there should be no balisitics drop or the round if properly zeroed in at 200 yards if zeroed in at 100 yards you'll be 1.6"-2.0" low so aim that much higher.

It's not calculus, Trig, or quantum physics it's easy. Any high school graduate should be able to figure it out.

Next lesson windage and elevation hold-off's

twl
07-08-2007, 5:30 AM
If you are resourceful, you can range with almost any scope.

Most scope manufacturers publish the reticle subtensions of all parts of their reticles. Often, this information is right in the user manual.

If you know the reticle subtensions at 100yds, you can use that information to range, and also possibly to do some bullet drop compensation.

For example, let's say you have a basic duplex reticle pattern.
With that reticle, you have things such as the thickness of the thick segments of the reticle, the thickness of the thin segments of the reticle, the distance between the center crosshair to the points of the thicker part of the duplex reticle, the distance between the thick points of the reticle from one side to the other.

Basically, if you know what each dimension of that reticle pattern subtends at 100yds, you can use the math to do the ranging.

Back in the "good old days" this was the way people did things.

M. Sage
07-08-2007, 6:49 AM
Practice with this:

http://www.shooterready.com/lrsdemolow.html

I tried that.. I have no idea how much wind drift to account for, and without any idea of bullet drop or especially what range the rifle's zeroed at...

I'd love to get the CD and learn, though.

Pthfndr
07-08-2007, 7:22 AM
Height of item in inches x 27.8 (25.4)/Mils read = Distance to target in yards (meters).

Target = man = 6' or 72" = 5 mil, 72" x 27.8 = 2001.6 / 5 mils = 400.3 yards
with a 150 grain .308 I'd aim 24" high to compensate for ballisitics drop.

Same target man = 5'9" = 4 mil, 69" x 27.8 = 1918.2 / 4 mils = 479 yards
with a 150 grain .308 I'd aim 48" high to compensate for ballisitics drop.

Same target man = 5'9" = 10 mil, 69" x 27.8 = 1918.2 / 10 mils = 191.82 yards.
with a 150 grain .308 I'd aim dead center on the cross hairs as there should be no ballisitics drop or the round if properly zeroed in at 200 yards if zeroed in at 100 yards you'll be 1.6"-2.0" low so aim that much higher.

It's not calculus, Trig, or quantum physics it's easy. Any high school graduate should be able to figure it out.

Next lesson windage and elevation hold-off's

You'd make a good teacher. Quoting the equation is easy, but some people who are new to ranging might not understand it. Your examples clearly show how it's done.

When you say you're holding 24" or 48" high, are you just guesstimating how far over the target you're holding, are you using the mildots / mil lines, adjusting the elevation? What's your allowable POI radius for a hit in terms of accuracy?

Just trying to get more information out. I know what I can do, I'm just a lousy teacher.

glockman19
07-08-2007, 8:54 AM
When you say you're holding 24" or 48" high, are you just guesstimating how far over the target you're holding, are you using the mildots / mil lines, adjusting the elevation?
I'm using the mil dots to estimimate the distance and elevation. I know the BDC, Ballistics Drop Compensation for the round I'm using and adjust accoordingly. I ZERO all my rifles in @ 200 yards. Look up the balistics for the round you're using and plan accordingly.

What's your allowable POI radius for a hit in terms of accuracy?

I'm happy with a shot that would be a kill on game that woud represent a heart/lung shot. Also good on human targets. If aiming for center mass I'm happy with a shot that is 2" to 5" depending on distance. Approximately no greater than the palm of your hand.

I have achieved groups of <1" @ 100 yards or less, <2" at 200 yards 4" at 400-500 yards and 5" groups @ 600 yards. As soon as I can tighten them up a little more I'll extend my targets further. Obviously even at longer distances if you're holding the same shot your groups will be tight but off of the mark. You can always get sub MOA groups @ 500 yards but if you're off the point you're targeting by 5-6" you can adjust.

I don't expect to ever take a game shot while hunting at more than 300-400 yards.

Paul
07-08-2007, 2:58 PM
I'm pretty good with my ACOG - the center "spokes" from the crosshairs are 18 moa - the width of a man's chest at 100 yards. I've got a mil-dot but cheat with a mil-dot master. Need some more practice time behind the thing.

Pthfndr
07-08-2007, 9:12 PM
I'm using the mil dots to estimate the distance and elevation. I know the BDC, Ballistics Drop Compensation for the round I'm using and adjust accoordingly. I ZERO all my rifles in @ 200 yards.


I understand how you estimate the distance. I was asking how you determine how you're holding xx inches high. In other words, are you literally holding your cross hair what you think is 24" or 48" above COM in your examples, or thinking "ok, I need to hold xx mils above COM", or what?

I zero at 100 yards. I used to zero at 200 but for reasons explained to me by better shooters than myself I switched to a 100 yard zero. It's worked out better for me in the long run.

Oh, and I got my dope down pretty good :)

I can't do this every time, but I can do it about half the time if I don't screw up my wind call and hold steady. It's at 900 yards on a B27 pistol silhouette target. That's what we use in our 1000 yard tactical matches.

http://img.photobucket.com/albums/v47/Pthfndr/900yardgroup.jpg

glockman19
07-09-2007, 7:34 AM
are you literally holding your cross hair what you think is 24" or 48" above COM in your examples, or thinking "ok, I need to hold xx mils above COM", or what?
YES I know the mil is 3.6" @ 100 yards. so I calcualte the drop based on yardage and hold-over accordingly.

The reason I ZERO in @ 200 yards is because the round I most commonly use a .308 147 grain FMJ is naturally flat @ 209 yards. That way I'm approximately 1.9" high @ 100 yards. 0 @ 200, -8.1 @ 300, 23.6 @ 400, and -48 @ 500 yards.

I suggest Zeroing in based on balistics rather than just at 100 yards. Of course Go with what works for you.

BTW nice shooting

rksimple
07-09-2007, 6:56 PM
I did.

1 mil = 3.6" @ 100 yards
1 foot = 2.8 mil @ 100 yards

Estimating the height of the object you're aiming at can be calculated in to distance by the number of Mil's. Once again for those who didn't get it the first time:
Height of item in inches x 27.8 (25.4)/Mils read = Distance to target in yards (meters).

Target = man = 6' or 72" = 5 mil, 72" x 27.8 = 2001.6 / 5 mils = 400.3 yards
with a 150 grain .308 I'd aim 24" high to compensate for balisitics drop.

Same target man = 5'9" = 4 mil, 69" x 27.8 = 1918.2 / 4 mils = 479 yards
with a 150 grain .308 I'd aim 48" high to compensate for balisitics drop.

Same target man = 5'9" = 10 mil, 69" x 27.8 = 1918.2 / 10 mils = 191.82 yards.
with a 150 grain .308 I'd aim dead center on the cross hairs as there should be no balisitics drop or the round if properly zeroed in at 200 yards if zeroed in at 100 yards you'll be 1.6"-2.0" low so aim that much higher.

It's not calculus, Trig, or quantum physics it's easy. Any high school graduate should be able to figure it out.

Next lesson windage and elevation hold-off's

You're making it harder on yourself. You only need to worry about inches (or cm) when looking at the size of the target. When it comes to trajectory forget about inches and get your dope in MOA and mils. Instead of having to convert to inches from mils or MOA (depending on the subtensions of the reticle) you only have drop and windage values in MOA and mils. Right now on my dope card I have values in MOA and mils only. If I had a scope with reticle subtentions and adjustments matching, I'd only need one value on my dope card, be it MOA or mils. It makes it much easier to think about things on the fly.

At the last Vegas match, we had a stage involving targets at 100, 200, 300, and 400 yards. The RO would yell out the target to shoot and using holdovers/unders, you did the best you could as it was scored for hits and time for 12 rounds. I set my scope to my 400 yard zero and used holdunders for everything closer. Knowing my trajectory in mils made it much easier instead of having to convert anything from inches to mils or vice versa.

olegk
07-09-2007, 7:49 PM
Practice with this:

http://www.shooterready.com/lrsdemolow.html

Another one:
http://www.horusvision.com/