I never was bothered by my CA M24 not having a safety (the stock one is pathetic anyways), I have a firm trigger pull (Fox_111's M24 is about the same, not as heavy as he says since I worked on it) on it, even when shooting 500fps, and never worried about it going off, because it never has when cocked. There are numerous times I'll load a round and aim at a guy, only to have him move away and I gotta get going, I'll just sling it as is and move on.
My KJW M700 on the other hand, I used it one game, had it slung, cocked and locked with safety on, at one point I think a small branch got in the trigger guard while the rifle was on my back, it fired. I pulled it off to find the safety was still on. Baffling at the max since I was unable to fire it with the safety on later. Is like the branch tapped the safety off, fired the gun, then put the safety back on.