Version 1.0 20 March 2020
Original program live to Internet

Version 1.1 22 May 2020
New shot start pressure model incorporated
New barrel friction model incorporated
New heat loss to barrel model incorporated

Version 1.2 29 May 2020
All Vihtavuori N100 powders (except N105) and N500 powders incorporated

Version 1.3 02 June 2020
Vivacities of all powders increased by around 5% to reconcile the fact that the model assumes the bullet is touching the lands whereas most reloading handbook data is for the bullet off the lands. This should correct a general trend for velocities to be low.

Version 1.4 09 June 2020
Improved equation for 'work done' put in.
Bug in Runge Kutta 2nd order interpolation corrected. (Simulator results now independent of delta t up to 100 microsecond time step).
Chemie-Swiss and Vihtavuori powder models re-calibrated for improved simulator function.

Version 1.5 01 July 2020
Modification to powder models allowing vivacity at Z = 0 to be set. All vivacities at Z = 0 set equal to given vivacities at Z = 0.1, so nominally the powder models are unchanged. Change in the vivacity interpolation method so that vivacities between Z = 0 and Z = 0.1 are interpolated and not fixed. Changes should mean powders are slightly more progressive, so this will reduce pressures slightly with little change in velocity.
Feedback form removed.
Change in counter analytics so that day of use rather than day of entry is recorded in the analytics file.

Version 2.0 13 November 2020
New powder model introduced with standard vivacity curve. 
The variables now for each powder are the average vivacity, the bulk density and whether it is single or double based.
The value of Z with time is determined directly from the vivacity, no knowledge of the powder kernel shape or dimensions is required.
Vihtavuori N555 powder added.

Version 2.1 19 November 2020
IMR powders added
Pressure-Time curve starts at one tenth maximum pressure
Pressure field colour now calibrated for 1 bar = 14.5 psi.

Version 2.2 24 November 2020
Lovex powders added
303 calibre added

Version 2.3 16 February 2021
Norma powders added
303 calibre adjusted for .310 groove diameter

Version 2.4 21 February 2021
Monolithic solid bullet type added

Version 2.5 2 March 2021
Alliant powders added

Version 2.6 31 March 2021
Removed the velocity at P-max output
Inserted a barrel time from 10% P-Max output
Re-ordered the outputs to separate muzzle velocity and muzzle energy, as they usually have similar numbers and can be confused with each other.

Version 2.6 16 May 2021
The term 'usable case capacity' was changed to 'powder space' because people were not reading the program information, or the manual, and were confusing usable case capacity with case capacity to the case mouth.

Version 2.7 27 June 2021
Shot start pressure model changed

Version 2.8 18 January 2022
Calibre .585 added