I bought a soft case with foam padding (actually, it's more like a backpack bag with zippers). I have heard the foam is nortorious for moisture. I plan to keep my gun in the case at all time.

Any recommendation? Should I exchange it with a hard case? What would you guys recommend for desiccant?

This all depends on where you plan on storing the whole package.  If you are throwing it under your bed... leaving the gun in foam is fine.  I have had a Winchester 70 sniper rig in a Pelican long case for like years on end sitting in the corner of the room without moisture issue.   The case is essentially a foam sandwich.

If you are planning on storing it in your garage or soemthing...  where temps can go up and down overnight.  You'll be better off leaving it in a open air system (ie gun rack) and keeping it lub up with CLP.

In my experience... if you keep your rig lub up with CLP, store it in a cheap-ass foam case, and don't fondle the rifle every chace you get (ie: getting sweat and acid on the gun)... it'll hold up fine without  desiccant packets.  I generally don't recommend soft case unless you don't care about the finish... the soft case will rub at it.  I have seen USMC M40 setup in the field stored in drag-bags without moisture issue... but man, it mess up the finish fast ~NewbieDave

Good point. I live in TX where humidity is a big problem.

blue crystal kitty litter from wally world packed in envelopes

i use to keep my  guns locked in cases w/ foam

then i got too many guns, and i got sick of wiping the guns down after taking em out b/c they got rust setting in

they stay in my closet now

Quoted: blue crystal kitty litter from wally world packed in envelopes i use to keep my  guns locked in cases w/ foam then i got too many guns, and i got sick of wiping the guns down after taking em out b/c they got rust setting in they stay in my closet now

+1

But that crystal litter creates lots powder. I am afraid that crystalline powder may damage my action or barrel.

Quoted: But that crystal litter creates lots powder. I am afraid that crystalline powder may damage my action or barrel.

pour it into bottles and use some type of fabric to cover the opening and leave it in the corner.

I've been putting the crystal kittie litter in coffee filters-I think they pass moisture faster than about anything else.  I thought about making a bunch of cloth bags, but just stapling a coffee filter over a tablespoon of litter is just too easy.