Where the chant is death,
death until the sun cries mourning.
Down to the park with friends of mine.

For those who remember my post about making a ballistics calculator for under $200.00 sale price per unit, I suceeded. Beta tests went great and the next prject objective is to toughen up the base hardware. My unit essentially a heavily modified ti-83.

Anyways you won't get the full version that tells you what a projectile will do, but I did make a TI-BASIC version of the Click Calculator. I haven't fully tested it, so Consider it an alpha release. Those with ti-83, 84, 83SE and 84SE can compile this program and use it. I only ask that you report any bug errors as I was pretty tired when I cranked the alpha out because spring semester starts soon. Anyways here is the code:

ClrHome
:Output (3,1, Click Calculator)
:Output (4,1, Burn Ballistics)
:Output (5,1, Alpha Release)
:Pause
:ClrHome
:Lbl M
:Menu( Click Calculator,Click Calculator, A1,Conversions, A2 , About , A3, Exit, EX)
:ClrHome
:Lbl A1
:Menu( Adjustments,1/4 MOA, B1,1/8 MOA, B2 , Custom , B3, Back, M)
:Lbl B1
:Disp Range in yards
:Prompt R
:(((((R*36)*2)*π)/360)/60)→M
:(1/4)→C
:Disp Drop (Inches)
:Prompt D
:((M/(C))→V
:(D/V)→A
:Disp A
:Clicks
:Pause
:ClrHome
:Goto A1
:Lbl B2
:Disp Range in yards
:Prompt R
:(((((R*36)*2)*π)/360)/60)→M
:(1/8)→C
:Disp Drop (Inches)
:Prompt D
:((M/(C))→V
:(D/V)→A
:Disp A
:Clicks
:Pause
:ClrHome
:Goto A1
:Lbl B3
:Disp Range in yards
:Prompt R
:(((((R*36)*2)*π)/360)/60)→M
:Disp 1 click and 100 yd
:Prompt C
:Disp Drop (Inches)
:Prompt D
:((M/(C))→V
:(D/V)→A
:Disp A
:Clicks
:Pause
:ClrHome
:Goto A1
:Lbl A2
:Menu( Conversions,Yds. to M., C1,In. to Cm., C2 , M. to Yds. , C3, Cm to In.,C4, Back, M)
:Lbl C1
:ClrHome
:Disp How many yards
:Prompt Y
:(Y*0.9144)→M
:Output(4,2, M)
:Output(5,2, Meters)
:Pause
:
:ClrHome
:Goto A2
:Lbl C2
:ClrHome
:Disp How many inches
:Prompt I
:(I*2.54)→C
:Output(4,2, C)
:Output(5,2, CenWebOffters)
:Pause
:ClrHome
:Goto A2
:Lbl C3
:ClrHome
:Disp How many meters
:Prompt M
:(M*1.0936133)→Y
:Output(4,2, Y)
:Output(5,2, Meters)
:Pause
:
:ClrHome
:Goto A2
:Lbl C4
:ClrHome
:Goto M
:Lbl A3
:Output (3,1, Click Calculator)
:Output (4,1, Version 1.0)
:Output (5,1, Burn Ballistics)
:Disp A different face
:Disp but the words
:Disp never change....
:Pause
:ClrHome
:Goto M
:



Here are directions on how to compile the program:
Go to this site: http://ti.zewaren.net/en/83p-creator.php
Paste the above code into the text box.
Name the program ClickCal
Write Bodegas Consummations in the comments box
Click Update
Click Save as 83P/8XP
Load program onto Calculator
Use Program
Report errors to me and request Improvements for the free Click Calculator
Refrain from asking me for the assembly version that calculates wind drift and bullet drop
.

Calculating Minute of Angle

To understand scope adjustments, you need to be able to calculate minute of angle (MOA). MOA is derived from simple geometry. I won't bore you so here is the formula to calculate MOA at a specific range in yards:

(((((r*36)*2)*Pi)/360)/60)=M

r= range in yards

m= MOA


Let's break down the formula:

Where does the 36 come from?

36 is how many inches are in 1 yard. We work with inches because that is typically standard and 1 MOA is almost 1 inch @ 100 yards. Below is the conversion for you:

1 yd. *(3 ft./1 yd.)=3 ft.

3ft * (12 in./1 ft.)=36 in.


Why multiply it by 2?

We multiply the first part of the equation by two because we calculate MOA using the radius of a circle (1/2 of the diameter aka distance acros the midesection of the circle)

Why divide by 360?

Because there are 360 degrees in one circle.

Why divide by 60?

Because there are 60 minutes of arc in one degree.

EXAMPLES


What does 4 MOA equal at 850 yards?

Step 1: Recall the MOA formula:

(((((r*36)*2)*Pi)/360)/60)=M

r= range in yards

m= MOA


Step 2: Plug in 850 for r:

(((((850*36)*2)*Pi)/360)/60)=M


Step 3: Solve using order of operations:

(((((850*36)*2)*Pi)/360)/60)=M

((((30600)*2)*Pi)/360)/60)=M

(((6120)*Pi)/360)/60)=M

((192265.4704/360)/60)=M

(534.0707511/60)=M

M=8.901179185 in


Step 4: Recall we wanted to know what 4 MOA was at 850 yards:

8.901179185*4=35.60471674 inches

It's obvious you would most likely round the answer to two decimal places.

What does 1 MOA equal at 83 yards?

Step 1: Recall the MOA formula:

(((((r*36)*2)*Pi)/360)/60)=M

r= range in yards

m= MOA


Step 2: Plug in 83 for r:

(((((83*36)*2)*Pi)/360)/60)=M


Step 3: Solve using order of operations:

(((((83*36)*2)*Pi)/360)/60)=M

((((2988)*2)*Pi)/360)/60)=M

(((5976)*Pi)/360)/60)=M

((18774.1577/360)/60)=M

(52.15043805/60)=M

M=0.8691739675 in


Here are approximations of MOA at common ranges (100 yard intervals)

1 MOA @ 100 yards = 1 inch
1 MOA @ 200 yards = 2 inches
1 MOA @ 300 yards = 3 inches
1 MOA @ 400 yards = 4 inches
1 MOA @ 500 yards = 5 inches
1 MOA @ 600 yards = 6 inches
1 MOA @ 700 yards = 7 inches
1 MOA @ 800 yards = 8 inches
1 MOA @ 900 yards = 9 inches
1 MOA @ 1000 yards = 10 inches

Next post will be on scope adjustments.

Scope Adjustments 101

Adjusting your scope is a vital part shooting at long ranges. It is realy simple once you learn how to calculate MOA.

D/(M*C)=A

D= Drop (inches)

M= MOA at target distance

C= what one click is @ 100 yard on your scope

A= adjustment in clicks


EXAMPLES

We will use the previous examples from "Calculating Minute of Angle".

What does 1 click equal at 83 yards if your scope has 1/4 MOA adjustments @ 100 yards?

Step 1: Calculate MOA

(((((83*36)*2)*Pi)/360)/60)=M

((((2988)*2)*Pi)/360)/60)=M

(((5976)*Pi)/360)/60)=M

((18774.1577/360)/60)=M

(52.15043805/60)=M

M=0.8691739675 in


Step 2: Recall the Click formula

M*C

Step 3: Plug in M and solve:

0.8691739675 in. * (1/4)=0.217275 in.

What does 1 click equal at 850 yards if your scope has 1/8 MOA adjustments @ 100 yards?

Step 1: Calculate MOA

(((((850*36)*2)*Pi)/360)/60)=M

((((30600)*2)*Pi)/360)/60)=M

(((6120)*Pi)/360)/60)=M

((192265.4704/360)/60)=M

(534.0707511/60)=M

M=8.901179185 in


Step 2: Recall the Click formula

M*C

Step 3: Plug in M and solve:

8.901179185 in * (1/8)=1.112647398 in.

Most people round their answers to usable numbers.

Next episode: Scope Adjustments 102

Scope Adjustments 102

In the previous lessons you have learned how to calculate MOA and what 1 click on your scope equals at a given range. Now you get to put it all together.

Recall the scope click formula:

D/(M*C)=A

D= Drop (inches)

M= MOA at target distance

C= what one click is @ 100 yard on your scope

A= adjustment in clicks

In Scope Adjustments 101 you learned the "M*C" part of the equation.

EXAMPLES

We will use the examples from scope adjustments 101:

You are shooting high by 5 inches at 83 yards. Your scope has 1/4 MOA adjustments at 100 yards. How many clicks do you adjust your scope?

Step 1: Calculate how many inches 1 click equals:

0.8691739675 in. * (1/4)=0.217275 in.

Step 2: plug the answer into the Click formula:

5 in./0.217275 in = 23.01231159 clicks

Step 3: Round the answer to the nearest whole number.

23 clicks

Your bullet will drop 125 inches at 850 yards. Your scope has 1/8 MOA adjustments at 100 yards. How many clicks do you adjust your scope?

Step 1: Calculate how many inches 1 click equals:

8.901179185 in * (1/8)=1.112647398 in.

Step 2: plug the answer into the Click formula:

125 in / 1.112647398= 112.3446657

Step 3: Round the answer to the nearest whole number.

112 clicks

That's it. You now know how to adjust your scope. This is a slap together guide, so I appologize in advance for any mistakes I may have made.

Thank you kind sir. The ti-83 is the basic graphing calculator isnt it? Great thread!!!!!!

Thank you kind sir. The ti-83 is the basic graphing calculator isnt it?

That's right. New they run about $90.00. You can find them used for less than $70.00. Throw another 10 in for the link cable and the software to sync programs is free. It also runs on a stock TI-83.

That's right. New they run about $90.00. You can find them used for less than $70.00. Throw another 10 in for the link cable and the software to sync programs is free. It also runs on a stock TI-83.

Well i just happen to have one from a math class i took around here somewhere. God I am horrible with the graphing calculator though.

Great job on the free software.