They're often listed as milspec, but spec'd for what application? What exactly are the specs on these cables?
Milspec is simply a term that refers to a standard set of specifications for anything manufactured that is qualified for procurment by the Department Of Defense. Stress "Anything"....building materials, foodservice equipment, personal items, and components of combat weaponry also have milspec standards. Each item or assembly has a unique code where numbers and letters in a given sequence describe the material, and can be referenced.
For the wire we are repurposing for recording, MIL-DTL-55021/2 which applies to shielded twisted pairs and triples for internal wiring intended for operating in a temperature range from -65 to 200 ÂșC. This is the only milspec wire suitable for arerospace applications, requiring an extruded PTFE (Teflon) jacket. Within the spec, various guages of wire, numbers of strands, and metal compositions are there. When you are considering milspec for field use, guage of conductor wire and the number of strands, the guage of the wire used for the shield, and the metal composition is what determines how flexible a cable is, the PTFE jacket is not as much a factor.
Any mic cables made using milspec MIL-DTL-55021/2 silver clad OFC copper wire for both conductor and shield, with conductor guages in the 20 to 22 awg range with low strand counts, extruded PTFE jackets over the conductors and the shield, and Nutrik XLRs will kick ass. Techflex looming adds great protection for the outer Teflon jacket, especially the top end Flexo that uses PolyPhenylene Sulfide (PPS) monofilament.