Advanced Marksmanship Extreme Long Range at Gunsite, Oct 10-12

[CoryT]

Time once again for the XLR class at Gunsite, comming up pretty quick now, October 10-12. Still have a few slots open, so if you've got the big gun and want to shoot out to 2k meters, this is the class. Call me if you like with any questions, (928) 636 4565, option 3

 

[Graham]

Re: Extreme Long Range at Gunsite, Oct 10-12

I attended last year and it was well-worth the 28-hour drive (with the obligatory stop at GAP, of course). The sign of the chicken is the sign of serious learning. Take sunscreen and remember to bring an open mind!

 

[Lowlight]

Re: Extreme Long Range at Gunsite, Oct 10-12

Hmm,

I believe my calendar is free... I may have to sign up for this one.

 

[Graham]

Re: Extreme Long Range at Gunsite, Oct 10-12

Frank, I'm absolutely serious:

Solving for Oblique Triangles - what do you do when you can’t get a right triangle?

The formula is more complex, but the process is the same.

Without giving too much away except basic geometry, an example:

Azimuth from A to C = 75
Azimuth from A to B = 47.5
Azimuth from B to C = 77
The difference between the two azimuth readings from point A is the angle A
Angle A = 27.5 [75 – 47.5]
Angle B is the back azimuth from A minus the Azimuth to C
Angle B = 150.5 [(180 + 47.5) – 77]
The sum of the angles in a triangle is 180 degrees, therefore:
Angle C = 2 [180 – 27.5 – 150.5)
Now we can calculate the ranges...

 

[CoryT]

Re: Extreme Long Range at Gunsite, Oct 10-12

LL, it would be a pleasure to have you come down, hope you can make it, it's great good fun!

 

[Lowlight]

Re: Extreme Long Range at Gunsite, Oct 10-12

Awesome I will call you up this week, like me double check the dates.

 

[mouse07410]

Re: Extreme Long Range at Gunsite, Oct 10-12

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Graham</div><div class="ubbcode-body">Frank, I'm absolutely serious:

Solving for Oblique Triangles - what do you do when you can’t get a right triangle?</div></div>
Graham,

I may be dense today, but I absolutely don't get it. What's the big deal with triangles, right-angled or oblique? It's middle- to high-school trigonometry. You need at least two angles and one distance to solve them. The Law of Sines is your friend (or should've been since those misspent school years

). If you have only the angles but not even a single distance (side) - you're stuck (wrt. finding the distance to the 3rd point).

Trigonometry: Oblique triangles
Google Books: Trigonometry - Practical Applications

So what's this all about? Converting azimuths to angles? Like, azimuth of point A is 10 degrees, azimuth of point B is 111 degrees - therefore the angle between points A and B is (111-10)=101?

Or is it April 1st yet?

 

[Lowlight]

Re: Extreme Long Range at Gunsite, Oct 10-12

Passive Range estimation is what he is talking about Mouse.

 

[Graham]

Re: Extreme Long Range at Gunsite, Oct 10-12

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mouse07410</div><div class="ubbcode-body">So what's this all about?</div></div>It's about running a base line. And about interfacing a GPS to FFS, which will allow you to get the range from GPS position data as well as calculate the solutions. Or, it's about learning to do it longhand: Since UTM or MGRS coordinates supply an Easting and Northing value in meters, you have the sides of a right triangle.

See Cory, like Plato with Socrates, I took notes.

 

[CoryT]

Re: Extreme Long Range at Gunsite, Oct 10-12

Well done sir, nice to know SOMEONE listens whilst I wax poetic up on the podium.

 

[mouse07410]

Re: Extreme Long Range at Gunsite, Oct 10-12

Graham,

If e.g. you have two people taking bearings of the target, then - adopting Law of Sines to azimuth we get:

Z1 = azimuth from spotter to target;
Z2 = azimuth from shooter to target;
Z3 = azimuth from spotter to shooter;
c = distance between spotter and shooter;

Range form shooter to target = c * sin(Z3 - Z1) / sin(Z1 - Z2);

Close enough?

If you have GPS coordinates of the shooter and the target - nothing to sweat, really. If you have GPS coords of shooter and spotter - well, convert those to Z3 and c and apply the above math. To get range from one GPS position data, or get target's GPS position without shaking hands with it (e.g., by just figuring out where it is on the map and being accurate enough placing it) - well, those boots are too big for me.

Now if FFS does all that for me (or for you

) automatically - nice!

 

[Graham]

Re: Extreme Long Range at Gunsite, Oct 10-12

One needs to derive the sides of a triangle using its angles. As I remember my math texbook (before I dropped the course due to a failing grade), side b would be something x SIN B x (1 divided by SIN C).

When using coordinates one must subtract the easting and northing values, then apply the Pythagorean theorem. It's like adventure racing, but without all the physicality.

 

[mouse07410]

Re: Extreme Long Range at Gunsite, Oct 10-12

Yep. So now one must carry a PDA in the field.

Suits me!

 

[ctressler]

Re: Extreme Long Range at Gunsite, Oct 10-12

Is this class full? Cost?

 

[CoryT]

Re: Extreme Long Range at Gunsite, Oct 10-12

There are still a couple slots available, $995 for the three days. Call Karen or Dave at the office, (928) 636 4565

 

[kmussack]

Re: Extreme Long Range at Gunsite, Oct 10-12

mmmmmmmmm?????? thinking............

 

[Lowlight]

Re: Extreme Long Range at Gunsite, Oct 10-12

K-Dog, I am gonna call today,

Thinking this is a good opportunity

 

[linebaugh500]

Re: Extreme Long Range at Gunsite, Oct 10-12

Kevin, you know I'm in for a third go-round...

 

[Graham]

Re: Extreme Long Range at Gunsite, Oct 10-12

It would sooo be like a reunion...you guys are killing me, because I can't make it!!

 

[Lowlight]

Re: Extreme Long Range at Gunsite, Oct 10-12

Want to Thank Cory & Giles for an excellent class.

The target package was excellent and pushed my equipment beyond it's capabilities.

After zeroing and calibration of Field Firing Solutions we shot from 1080m to 1955m, where at 1955m my scope was maxed out at 23 mils requiring me to hold .5 over giving me a 3rd round hit.

it was definitely a challenge, to including hitting a 12" Pepper Popper at 1380m. Changes in the light make the camouflage targets difficult to find, and placing them on the crest of a hill made it important to spot your trace.

Weather conditions we perfect, wind was light but seriously challenging with the direction switching from left to right between each shot.

On the last day shooting the unknown distance targets I managed about 4 first round hits, farthest was 1520m, a bunch of second round hits, with about an equal number of 3rd or more. Realistically speaking I would say my average across the course on unknown distance targets beyond 1200m was right around 3 shots. Some were better, some worst, with one important safety tip learned,

<span style="font-style: italic">when you switch from a PLRF 10c range finder to a Vector 21 remember to change the yards to meters in your PDA. it makes a big difference.</span>

Cory & Giles made themselves very available to us, and everyone was given the opportunity to shoot at night using the Ashbury International 338 w/ Knights PVS-26. We located and engaged a target at 700 yards, beyond easy.

Thanks again to all, enjoyed it, as well learned a thing or two about putting rounds downrange at distances beyond 1000m.

 

[bvt]

Re: Extreme Long Range at Gunsite, Oct 10-12

Lowlight, did you use the 338 exclusively, or did you bring another rig?

 

[Lowlight]

Re: Extreme Long Range at Gunsite, Oct 10-12

I just used my GAP 338LM and 250gr Scenars from SW Ammo... nothing else.