I know its a drill round so nobody is actually going to shoot it but a bullet cut off like that (to that extent) and drilled is going to quite likely shoot the core out leaving the jacket stuck in the rfling. So IMO I would have said its home made, except for the crimp which leaves a doubt in my mind.
People do sporterise military bullets that way, and quite a lot, but it doesn’t strike me as a particularly well informed attempt. Interestingly, the crimp looks factory original so it may be that somebody has modified the bullet at a later date to make it more interesting/ collectable/ sellable as a Dum Dum to the uninformed.
The primer strikes are quite interesting too because one of them is off centre. A common problem with old Lee Enfields that have a loose or worn bolt which tends to float around a bit at the business end because the bolt lockup is at the rear. I wouldn’t expect to see it though on a rifle still in service.