Long Range Target Interdiction - Page 2

**Peregrino** · 03-13-2005, 20:48

LR1947 (and anybody else with an opinion) - A couple issues to stir the pot with. Rather than PM you, I hope to solicit/incite discussion in an open forum so everybody can benefit. Since we all seem to be in relative agreement about the scopes/reticles/etc. I thought I would explore a couple of related subjects that might be of interest to the group at large. It has been so long since I used an M24 that I would probably embarrass myself severely in an unknown range field shoot. What can I do to get back up to speed (with the scope)? Are there training aids/job aids that will assist me? I specifically had two things in mind: #1 - Unless I really screwed the pooch w/my search command, I couldn't find where anybody had discussed the Mildot Master sliderule thingy. You teach this stuff - is the Mildot Master worth getting for those of us who don't use the reticle for a living? Is it a crutch for Walter Mitties or a legitimate tool? And #2, check out this site -
http://www.shooterready.com/lrsdemolow.html. Have you seen this program and does it work? The demo makes for a neat game but the calculations don't seem quite right. I haven't seen the full program so I don't know if that's a feature of the demo. Inquiring minds want to know

- Peregrino

longrange1947 · 03-14-2005, 15:36

MilDot Master. We issue it to the students now and anyone wishing to use mil dots would be well served using that little handy device.

One way to aid in your miling is to reverse the formula so that you can "simulate" a range at another range. Example, if you only have 50 meters, then you make little 'E' types and print them up, Mil them and compute the range. Then measure them and see if you were right. Remember to use exact measurements and not averages. A mil has 3.427 moa, and 1 moa is worth 2.87 cm at 100 meters or 1.087 inches at 100 yards. Convert the size of the target in actuality into mils and then see what it would have equaled if it was really 1 meter tall as a real 'E' type.

I do not like the program on the internet as it does not compute and it can casue errors.

**Peregrino** · 03-14-2005, 16:06

Muchisimas Gracias! I'll check some sources and see where I can get the MdM for the best price. As for the program - a friend sent me the link and I had some fun playing with it until I stopped playing and started doing the math. I was wondering why my calculations weren't getting the hits I thought they should. I'm glad it wasn't (all) me. It also sounds like I need to add a calculator to the range kit. Thanks again - Peregrino

longrange1947 · 03-14-2005, 20:49

Peregrino - Actually for range work you can use 3.5 moa for mils and 1 moa equals 1 inch every 100 yards or 100 meters. The error is not enough to matter at normal ranges. Use 25.4 as a constant to change inches into meters, or 27.7 if you like to work in yards. If your target is in meters then use 1000. The formula words by chagning the sizr of the target into millimeters and dividing by the measured mils. Hence 25.4, number of mm in an inch and 1000 number of mm in a meter. The 27.7 is a formula number to trick the formula into giving yards as an answer. Use the calculator for figuring practice targets at shorter ranges. Make the targets anysize you wish and then measure them to see what they would be if they were a 1 meter 'E' type at that a simulated range. An example is that the target is used at 50 meters. Make the target out to be 10 cm and you have a target that is 2 mils tall or 500 similated meters away. .10 x 1000 / 2 = 500.

Desert Fox - What you are talking about is matching the exit pupil of the scope with your pupil size. Divide the Objective lens in mm by the power fo hte scope and you have the exit pupil. As an example 50mm divided by 8x equals 6.25mm, this would be slightly smaller then your pupil at night so you would have a hard time locating the true center axis of your lens. Go too large and you are wasting light on other than your pupil.

Sacamuelas · 03-14-2005, 21:17

Thanks for the explanation LR1947.

If I'm reading you right, then my Leupold 3x9x40 should give me the best lowlight visibility right around the 5.5x- 6x power setting as that gets me close to the 7mm average for a human dilated pupil. Right?

**Peregrino** · 03-15-2005, 09:27

LR1947 - I/we need to get you in the "professor mode" a little more often. Time to turn your info into a 3x5 and laminate it. Then I get to haunt SWFA http://samplelist.com until I find the scope I can't live without (or somebody points me towards a better deal). Thanks - Peregrino

DF - That's why the 7x50 bino's have always been the "gold standard" for military/naval low-light use. The package is an acceptable compromise for size and optical characteristics; the exit pupil is the optimal size, the objective lens is large enough to gather adequate light, the magnification is adequate - and about all you can stabilize in a hand-held optic. Any time you stray from that position the legs of your triangle start getting unbalanced. Notice the key here - compromise. To get more of one characteristic you have to give up something somewhere else. The only thing that seperates individual examples from each other is the quality of the glass (optical properties/light transmission/grind) and ergonomics. Price and name brand are "usually" good indicators of quality. FWIW - Peregrino

BMT (RIP) · 03-15-2005, 15:50

DAMN! I was thinking about using a 105 w/ VT fuze!!

BMT

Desert Fox · 03-16-2005, 14:30

LR1947,
you should write a book! I would be the first to buy it!

longrange1947 · 03-16-2005, 20:34

First off, there is a typo in my post on the mil to moa, it should have read 3.437 not 3.427. Sorry about my lousy typing and it slipped past my lousy editing. could be a reason I don't write a book.

On the exit pupil. watch how big you get the exit pupil as the bigger it is the less light falls on the retina. It is like the adjustable beam flashlights, the wider the beam the less light there is on the subject. Conversly the narrower the beam, the more difficult it is to find the exit pupil at night and the easier it is to shadow the scope. As the beam becomes tighter, and brighter, the more the pupil constricts, BUT that only works to a certain degree and that is dependant upon that particular shooter's physiology. With this comes more rapid eye fatigue. Another words, experiment. Each person will find that they have better operating condtions with a certain power setting on their scope that may not work worth a dam for me or someone else.

However a good quality scope with the correct power setting will allow you to shoot well after sunset and even later on a bright moon lit night. It is possible to better engage a target with the day scope under certain circumstances then with the NVD.

BMT - In many instances I have to agree on the bigger is better, even 155 seems very handy at times!

Tuukka · 03-20-2005, 18:45

One informative thread, very fortunate to be able to follow discussion done by professionals.

longrange1947, if i am not mistaken, i believe we have mutual friends, Major W. Stewart sends his regards!

longrange1947 · 03-21-2005, 00:10

Tuukka - Have a beer with him for me. He is a good man, even if he does love those Sakos.

Tuukka · 03-21-2005, 03:50

I met him at the IWA weapons expo where i was representing the suppressor company i work for, didnt have the chance to have few beers though.

About those Sakos, guess who got the TRG for him a few years back

longrange1947 · 03-21-2005, 20:14

Yes, I had heard that rumor. We played with the SAKO 338 and I liked it better than the AI.

Oh well, time will tell.