WinLoad.   Version 2.12
WinGyro.   Version 1.22

This program runs under Windows 95,98,3.xx
Use the TAB key or mouse to select the data boxes.
The package consists of two programs and will produce 
answers based on the data that you input.

It can be run from a floppy disk.  When the program is 
first run it will write back to the disk a file called 
winload.ini (and winload.dat if not already present)  
Please do not 'write protect' the disk.

To demonstrate the program I have included an 'example' 
file that you can 'Load' and run for each of the programs.

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WinLoad  Version 2.12

Based on Homer Powley's algorithms to calculate a load.
This program calculates a load that will give a STANDARD  
PRESSURE of 45,000 psi in copper units of pressure (CUP).

WARNING:
Increasing the powder charge by X% will increase the muzzle 
velocity by X% and the pressure by 2X%

Cross check all answers from this program with published 
data, especially data from the manufacturer of the powder 
that you are using.

CASE CAPACITY.

"the weight of water which fills the powder space in the 
cartridge behind the bullet".
An easy way to get this figure is to weigh an empty case 
plus bullet, next fill the case with water then insert the 
bullet to seating depth and finally weigh again. 
The difference between the two weighings is the case capacity.

or:
 
Refer to the data in the excellent book by John J Donnelly
'The Handloaders Manual of Cartridge Conversion', which gives
the case capacity in 'grns of water' for hundreds of cartridges.



=========================================================
WinGyro.  Version 1.22
Based on the "McGyro" program written by R.L.McCoy and 
subsequently adapted by Wm.C.Davis,Jr.               

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Text from the McGyro/McGyrsa programs 

"This program estimates the gyroscopic stability factor for 
spin-stabilized projectiles, from input of configuration 
dimensions, twist of rifling, and type of construction.
The program involves the assumption that the bullet is of 
uniform density. 
The density assumed for bullets of conventional materials and 
construction has been adjusted to agree with experimentally 
determined stability data for conventional bullets.
The program allows for direct entry of specific gravity for 
bullets made of unconventional materials.
The program output is the gyroscopic stability factor for 
the twist specified under standard sea-level atmospheric 
conditions.
Also output is the twist required for a standard stability 
factor of 1.5, which is generally the minimum stability factor 
consistent with good practice.
The standard deviations of the estimates are 5% at subsonic and 
supersonic velocities, and 10% at transonic velocities"

"The output table shows muzzle stability, not stability at 
remaining velocities"
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WinGyro Data

IDENTIFY PROJECTILE.
Give a name to the projectile for the printout.

MEPLAT.   (nose point diameter).
The flat front surface of a bullet.

BULLET CONSTRUCTION.
By editing the wingyro.ini file it is possible to alter the order 
in which the various types are displayed.
It is also possible to add items to the list.(There are instructions 
on how to find the specific gravity of a bullet in 'Hatcher's Notebook' 
page 557)
(The wingyro.ini file will appear after you run the wingyro.exe 
file for the first time)

BULLET OGIVE.
The ogive is the curve between the bearing surface and the point.
The radius of the curve is usually given in respect to the calibre.
The ogival radius has significance only as it relates to the bullet
diameter. The centre point of the radius is important as it controls 
the length and partly defines the shape.

TANGENT OGIVE.
The centre point of the radius is at right angles to the cylindrical 
surface and opposite the intersection between that surface and the 
curved ogive.
Most 144grn 7.62mm NATO bullets are struck with a 7.5 CRH (calibre 
radius head) ogive.

SECANT OGIVE.
The secant ogive has the centre point of the radius lower and opposite 
a point on the cylindrical bearing surface.
The position of the point of the bullet is described by the construction 
of a tangent ogive on the bullet. The ogive is then actually struck 
using a curve of larger radius.

RG (British 144grn 7.62mm NATO) bullets have a 6/13 CRH secant ogive. 
This means that the ogive length and hence position of the point is 
described by a 6 CRH tangent ogive, but the curve is struck by a radius 
of 13 CRH.

STABILITY FACTOR.(SF)
The value of SF must exceed 1 if the bullet is to be stable.
In practice the value of SF is arranged to be appreciably more than 1 
to give a margin of safety.  Military rifles and cartridges will 
usually have values of SF between 1.5 and 2.

John Knight.   
Bisley
UK       5 November 1997    

