Rifle Hard Case

Hey,

I am thinking of buying a Plano rifle hard case, does anyone know what the difference Plano 1511 (https://www.huntingandfishing.co.nz/...odel-1511.html) and 1531 (https://www.huntingandfishing.co.nz/...odel-1531.html) is?

Also does anyone have any other suggestions for quality hardcases (budget around $150)

Thanks!