Picked hundreds of .303 spent cases up on Dartmoor as a lad (old live firing range just up from where I grew up) That definatley looks like a brens strike mark but I have never seen one so dead centre, for some reason they were always off centre (and found in groups of 3...fire and manouvre?)
Not wanting to go off topic but I always wondered what is a 'ball' round? I mean what defines a 'ball' round from others, I mean I know what tracer is etc but had no idea there were different catagories? Genuine question and not a wah, just nobody ever explained and to be honest I never asked before, didn't seem important.
In the good old days when Mushie was a sprog we used to load our muskets with lead balls. Twas ball then and no one has yet tried to get their MBE for useless and pointless change by renaming it anything else.