I've been developing a way to make a device which could safely heat a firearm to 100F minimum and hopefully get near 200F.
1. Lots of air space
2. Don't take up lots of room when not in use
4. Electric heat only
Status so far: I'm using 1.5" x 1.5" x 8' studs for the frame. For the walls I'm using heating duct material 5' tube that is ~26" in circumference. I unrolled the duct material and stretched it out on the frame using decking screws (#6 x 1"). This will make up the 4 walls, which are all made separately to be non-permenantly attached later.
A 2' x 2' piece of wood will rest on the top of the walls with an eye-bolt hanging to suspend the firearms and parts. The eye bolt is attached loosely using large washers and 2 nuts to lock each other in place. This allows the eye-bolt to swivel.
Heating: The heat source will be a 500W halogen shop light. My friend uses them to heat candle gel to ~300+ degrees F, so this should radiate enough heat to meet the box's temperature requirements.
Anywho, that's the status so far. Hopefully I'll be testing it within a month. My first experiment will be to sweat the nasty cosmo out of a Yugo SKS.