Guns with hammers have long been recommended for kids since it's easy to see if they're cocked. Problem is, little hands have a hard time controlling that hammer and it's all too easy for a finger to slip onto the trigger during the struggle. One virtue of the hated Marlin cross-bolt safety is that it can prevent a whoopsie, but only if it's used. Best to stick with a light bolt action, I think, perhaps single-loaded, which might eliminate some of the detachable mag guns with small ports.
