Heck for stout case there! I'm guessing you used 3/4" material pretty much throughout. Back when I made boxes for friends for scatterguns, pistols, scopes and such, I made the sides of the box from 1/2" stock and the top/bottom from 1/4" to 3/8" material, depending on the way it was built. Yours should stand up to a few generations of use, given somewhat reasonable care.
I used to resaw full 4/4 and 5/4 stock for my box material. Pretty wood, BTW.