[FrankenMauser]

I keep up with GRT on a daily basis.
There is a lot of development going on and it may turn into a very useful tool at some point.
But, right now, it is still a Beta - arguably an Alpha.

Development aside, there is one very important thing to keep in mind about GRT:
Gordon has established certain pressure levels that he believes each cartridge should operate at. In most cases, this is band of pressure from CIP or SAAMI MAP for the cartridge, and down about 8-10%. There are some exceptions, but most adhere to that.
This is what all of the powder models are built around, and all data outside of this pressure band is eliminated and/or ignored.

The problem with this is that Gordon and GRT do no support subsonic loads for almost anything that isn't already subsonic (like 147+ gr 9mm, or normal .45 Auto). If you want to load subsonic .300 Blackout, for example, GRT gives you errors, because Gordon does not believe that subsonic loads are viable. He doesn't understand the purpose or application. Therefore, he doesn't want to spend the time to develop low pressure specific cartridge files, or allow the tool to work with wide pressure band powder models. (Like subsonic to supersonic .300 Blk.)

Basically, if Gordon doesn't believe in it, you don't get that functionality or data set.

Those of you that don't care about the example, .300 Blackout, probably don't see that as a problem, but I have seen discussions about this being applied to *many* cartridges where it will be a real point of argument or decision for some people. (And Gordon and his lackeys actively shooting people down for considering a reduced pressure/reduced velocity load for extremely common cartridges.)
You want some low pressure plinking loads for .44 Mag? You're out of luck.
Want some reduced velocity .30-30 for your niece to hunt with? Tough cookies. If it's outside the pressure band, Gordon doesn't support it.

Sometimes, Charlie will swoop in and try to tell someone how to force the program to do it by using the Optimum Barrel Time tool. But, even then, there are a huge number of disclaimers, it is a very complicated process, and you're intentionally force-feeding the program bad data in order to hamfist your way into a ballpark workaround.


Just keep in mind that GRT is not a finished tool, and that it is being developed by a person that is extremely opinionated about how each and every cartridge is supposed to be used -- with a squad of enforcers waiting in the wings to jump on anyone that questions it or tries to use it in a realistic manner that isn't exactly what they envisioned.
If your opinion and application do not align, GRT may be useless to you.
And if you speak up about it, the enforcers will dog-pile on you to stop the Wrongthink. (By submission or forced re-education.)