As has been said, the stock or pre-engineered weapons refreshes on a Thursday after the weekly tick. That being said, you would be surprised at the amount of good gear that can be found in the twelve hours before the weekly tick. Less travelled areas of the bubble are the best places to find stuff, unless you are first to visit. If you are on the fringes of the bubble, pick half a dozen systems there or around your base and APEX between them to check at the stores. After that, whenever visiting systems, check the stations as you are there anyway.
I bought a new CMDR in the steam summer sale, and within a week had a G2 Maverick + night vision, a G2 C-44 with noise suppression and a G3 Tormentor (still looking for one with a good mod). Having gone through the engineering unlocks already with previous CMDRs, I am not going to go through it again with this new one, and will stick to gear with a mod I want and carry on from there. Essentially I am sticking to the Maverick suit, a Tormentor and a C-44 to play with, as you can play the game without going down the engineering route, although I am going to upgrade to G5 eventually via the upgrading facility offered by the Pioneer Supplies.
I was weak, and on a Tuesday/Wednesday found a G2 Executioner + scope, so bought that as a third weapon. I like scopes!
Those in Colonia are at a disadvantage regarding the availability of pre-engineered gear, but the engineer unlocks there are so easy compared to the bubble it is a doddle to engineer gear.
Steve 07.