credits go to nick2012v since he came up with this idea xD
so for those who want to repeatedly gunadd a weapon (for me i have 700 days of ppsh!! xD) here is a method
after u find the address for the desired item just check the box for the address under active then just keep buying the item in the shop. And it will stay as the weapon for the gunadd til u change it!! No need for Alt-Tab repeatedly!
What would be more useful is if you could find out a way to mass buy a weapon. Because when I gun added for balaclava mask I had to press the buy button and ok button like 100 and it really wastes time, so if you could find a way to do that, I'm sure many people would really appreciate it.