Gordons Reloading Tool (GRT), How to Start Using
Back in June 2019, a new internal ballistics simulation program became available to the reloading community, it is known as Gordons Reloading Tool (GRT).
It was announced on TRN by Marcus of Wiederlader TV in the TRN post just below this paragraph. I had been using a similar program known as QuickLoad, but was very disappointed that it was missing so many of the modern powders now available, and that new models were not likely to appear. I decided to give GRT a try, but ran into the same lack of powder profiles for the USA market, and lack of many of the modern powders now available. I attempted to communicate with GRT through their Discord server channels, but was frustrated that the default language was German, and I had no ability to read or write German, let alone speak it. After some time I noticed that there was some English text being used on the Discord channels and the GRT Ticket System, so I ventured to ask a question in English, and was immediately bombarded with friendly responses in English. This immediately opened up communications, and I learned that GRT was looking for contributors from around the world to help develop the powders models that are lacking. It seems that Gordon has been able to develop algorithms that allow the reverse engineering of the required powder models as long as he gets sufficient Firing Results. At this point I realized that GRT had so much more potential than any previously available internal ballistics program, that I volunteered to supply as much of the USA powder models as I could afford to. I also realized that GRT was experiencing some adoption resistance here in the USA due to the lack of USA powder models and the perceived language barrier. I, therefore, am going to step outside my comfort zone and make a few video articles explaining how a user can acquire GRT, use GRT, and hopefully contribute to the powder model development. If successful, the reloading community here in the USA can build powder models for all the USA available powders, and keep them up to date.
If you watch this Weiderlader video, just click your browser Back button to return to this article.
I will start with the basics in this article including registering with GRT, downloading the software, and setting up. There will be some how to use demonstration, as well, and I hope I have not gone too fast. In later articles I will show how the user can overlay Pressure Trace II files over the simulation pressure curves, import MagnetoSpeed .csv data, LabRadar Data, and how to submit user load firing data to develop a powder model. If you are not familiar with what a Interior Ballistics program does, please read the excerpt below by Cassie Nienaber. Below that will be the first video of this series explaining how to acquire GRT.
Internal ballistics simulations by Cassie Nienaber of the GRT Powder Development Team.
Internal ballistics refers to the process happening inside a barrel during the firing of a weapon, from the time the propellant is ignited until the subsequent gas pressure sends the projectile out the muzzle. The study of internal ballistics involves the properties of the weapon and components, the pressures created by the burning propellant, the influence of these on bullet acceleration and the resultant muzzle velocity of the projectile.
Pressure and velocity can be projected by an internal ballistics (IB) program, which has the potential to remove a lot of guess work and can be an invaluable supplementary tool for reloaders. These programs were typically only used by and available to the major players in propellant manufacturing and research.
The way an IB program works:
The user chooses his calibre, bullet and propellant (powder) from the IB program’s data base. The physical properties like barrel length, case volume, case length, cartridge length and charge load are entered into the IB program. The program then mathematically computes the behaviour of the components during the firing process and produces the resultant internal pressure curve and muzzle velocity.
The Quickload program:
Until recently the only viable IB calculator available to domestic reloaders was Quickload. Quickload is a commercial personal computer based (PC) program that runs on Windows only, and sells in South Africa for R3,499.00 (equivalent to US $233.00, but about $160.00 in the USA). Quickload development started in 1985, before PC’s were commonly available for personal use and was initially programmed in Fortran. Later it was migrated to DOS and still later to Windows. Therefore, Quickload was not really developed for a modern graphical operating system like Windows and also lags behind in user friendliness. Furthermore, updates to its data base are not done regularly and is difficult to come by. It might also be that the internal ballistic formulae/simulations are outdated. These factors combined with the rather stiff asking price prevents a lot of reloaders from using Quickload.
A free alternative to Quickload:
A private initiative to create a free alternative to Quickload was started by Gordons Reloading Channel. Initially, out of pure interest and after studying the relevant literature, the program’s author (Gordon) decided to deal with the topic of interior ballistic simulation calculation and to develop his own software. Experience in thermodynamics, physics and also software development from his professional career were helpful. The author built a development team from a couple of reloading/programming enthusiasts, and created an IB program called Gordon’s Reloading Tool, GRT for short. GRT is supplied for free, is community supported, and is a cross platform application.
Because GRT is community supported it’s data base and powder models are continuously being updated and refined by user data feedback and inputs, which has a major influence on the excellent and true to life results achieved by GRT.
Watch this video to find out how to get GRT. I made this to show even the most timid computer user how to do it.
That’s all for now.
I started reloading in 1968 while attending college and spent 4 years (high school) under the direction of a US Marine field armorer. Having retired recently, and now that I have time to ponder my hobby instead of concentrating on working for some company, I have assembled some of the things that I think I have learned over the years of playing around with firearms.