Quickload is a useful modelling tool if you want to push things things to the limits or loading new or uncommon or wild cat cartridges and powders that are new or don't have broadly published test data / results. If you do a lot of tinkering this resource is worth having.
But is saying that any reloading app, program, manual or online reference is just a starting point; to safely choose an appropriate powder and starting weight for the projectile weight and cartridge of your choosing. Nothing can replace good scientific method for finding the best and safest load.
I just ordered QL yesterday. Looks to be back ordered till mid Feb
I was following book loads from low to high with Lapua brass and Lapua Scenar bullets and wasn’t getting any pressure signs on my brass or bolt lift. But I was getting high velocities even with 4” less of barrel compared to book loads, I was beating book load velocities.
Had some guys run data through QL for me and turns out with the reduced case capacity of Lapua and the long Scenar bullets, sammi pressure was being reach by approximately the mid load of the book value. That’s when the light clicked on and I knew I had to buy it, if only just for another safety measure.
Also the 6.5Guys have an Excel spreadsheet that calculates ES, SD, and plots your info on a graph. It's really nice to save your info. I use open source program to use it.