When I was present for catastrophic failures like this, except for an out of battery experience with a .50 cal...there wasn't much difference. An 8mm Bren blew upwards through the magazine and only the kaboom was different. An FN with BFA on just sounded different, a Remington stainless in 7MM gave a sharp crack instead of the normal boom and the barrel split lengthwise... Not much difference.
The .50 was like a bomb going off though, followed by the tracer burning to completion in the commencement... That was picturesque.