shotty storage
Are you referring to what's best for the gun, the operator or for safety??
Different answers.
Depends on the gun too.
It's obviously better for any firearms to be stored with the springs relaxed.
That said a lot of different ypes of firemarms aren't affected by leaving springs set and will tolerate the condition longer than you'll be around.
Safety issues are directly related to time/effort.
Prolly nothing safer than a dissasembled firearm. If you're willing to go the effort to dissasemble/reassemble the gun after/prior to use the chances of you or anyone elese coming in contact with it is going to have an AD is reduced to almost nill. Then when you throw in storing the dissassembled parts separately the risk is now ridiculously small.
As for the gun, well again time/effort is the deal. Arguably the gun would prefer to be dissasembled cleaned and greased/oiled and stored on velvet at 10deg and zero hunidity. So anywhere from this to still smoking,wet,dirty, and tossed into a steamy greenhouse is a compromise your time/effort will have to call.
Then there's the location issue. Lil kids and other hazards around? Live alone or with roomates? High crime area? Likely to have authorities pop in? How secure is your place/storage room etc?
Local laws/regs/bylaws etc?
No straight answer here. Ya gotta satisy the law(s), ya have to be able to look in the mirror.
Not a smartass answer, just the way it is.
Beyond laws, storage approaches, safety devices, safes, vaults ......
It all boils down to the very basics, whether you're storing/cleaning/carrying/hunting/fighting
Treat ALL guns like they're loaded.
ALWAYS check/prove a gun before you do anything else.
Never point a gun at anything you're not willing to destroy.
Finger NEVER goes on the trigger till you want it to go bang.
She's that simple.