Take out all rifle rests (it wastes space)... use rifle rods (look it up)... put back row grip forward and front row grip away (between each back row rifle)...
I have ___ long guns in one safe and ___ or so in another (smaller)... with room to put shotgun in each (they stay out of safe when I'm home) ... decided to omit the numbers (but it's more than plenty)
Don't use any organizer that came with safe... you should have one big open space... or two open spaces with one vertical divider (if you have a wide safe) ... I have one of each.