So I cleaned up the code and ‘reluctantly’ handed over the garbage collecting to UE4 rather than trying to do it myself in parallel. The bomb class has been recoded so the Destroy handling is internal to the class, the pointer to the bomb is used only to complete the initiation of each spawned bomb and then no longer referenced, UPROPERTY makes more of an appearance … and the game no longer crashes! Thanks for the pointers and advice … this really helped.