Ex MoD kit is usually well looked after if it was bench stuff. If it was field kit then you’re taking a gamble. Most of the damage actually appears at the muppets who sell it off who mistake it as being made as the same stuff as Land Rover wolf vehicles.
Service kit is funny. A squaddie can fuck up anything. I don’t know how they do it.
Based on my experience, and anecdotal evidence from colleagues and friends over the years, there is scale of reliability and toughness for equipment that goes thus:
A higher number implies tougher.
Level 0 - Suitable for use by the general population
Level 1 - Schoolboy proof
Level 2 - Squaddie proof
Level 3 - Policeman proof
Level 4 - Actor and musician proof
Level 4 is similar to Chimpanzee proof. Actors and Chimps have a lot in common: intelligent, curious and completely sex obsessed.
A zoologist one told me that given a piece of equipment a Chimp would smash it apart to see what was inside, a Gorilla would take it apart neatly to see how it worked, an Orangutan would take it apart and put it back together again, and a Gibbon would take it apart, put it back together again and hand you a list of improvements that they'd noticed could be made along the way.