Well my upper from Bushmaster has finaly arrived. 16" M4A3 patrolmens barrel 1/9 with M4 handguards. She's a Beaut! I now have a complete AR rifle. It took about Four or Five weeks and from what I've been reading on here I guess thats not to bad.
  My question is this, I heard a rumor that keeping a gun in an eggcrate lined case would or could cause Rust, is this true? I wrapped it in the plastic bubblewrap it came in before putting it in the case until I could Talk to you guys.
 
  Thanks for all the advice, Past and Present.

                              SILAS

Depending on your local climate, the typical open cell foam found in most cases can absorb moisture... It also has a habit of absorbing the CLP you've so lovingly applied to your AR, leaving it dry... A simple fix is to check out the local arts and crafts stores for closed cell foam.  Closed cell is what is used in Pelican and Starlight cases... I found several 4'x8'x4" pieces of closed cell for just a few dollars locally... Enjoy the new rifle...

I have both kinds of cases and store my rifles in both, room temp is about 75degrees and A/C runs ALL the time, i threw in a couple desecant paks and i dont latch the lid , i let the rifle hold it up some , been doin this for years with out a speck of rust. really depends on environment i suppose.