I have a large Plano crate I move in and out of my trunk. It usually has earmuffs, shooting glasses, scope/lens clearer cloths, some external batteries for my phone, and some scrap cardboard or paper I use for targets. I put whatever ammo, mags, and mag loaders I'm shooting that day. I also have a repurposed plastic jar I keep spent brass in to be reloaded later, and my reloading notebook if I'm shooting reloads. I should probably put the bug spray back in now that it's getting warmer...
I don't have a specific range bag. I keep all my shooting stuff organized in a set of school type lockers I have in my basement. When I go to the range, it's just with one or two specific firearms to train with, so it doesn't makes sense to me to have a bag set up with everything in it. I can find whatever bag or backpack is lying around, load it up with the specific things I need in about a minute, and go. When I get back, I unload everything back into the lockers.
Pelican 1615 Air that stores my plate carrier,belt kit and some breaching tools for work thar stays in my squad. When I go to the range I throw my range supplies in there with a fix it sticks tool kit with all the stuff for making adjustments.
Most of my range time is spent either teaching or working drills and testing courses of fire for my agency.
Looking to probably swap my 1615 for whatever the deeper version of the 1615 is as I really could use a little more capacity. However my current setup works pretty well for me. I dont typically use gun cases or anything. Guns just get cleared and thrown into the box or in my holster on the belt kit.