Earlier this year a British subject found an intact .50 caliber (calibre!) cartridge in his garden, evidently dropped there by an 8th AF bomb group back when. Much angst as to whether the cartridge was dangerous, diverting to differences in Euro and US laws/attitudes. IIRC if he failed to turn the thing over to The Authorities he could be prosecuted for violating The Queen's Regs, whatever they might be. Americans said dust it off and put it on the shelf. The sorta marginal images made it somewhat difficult to offer an informed opinion, but the concern about spontaneous ignition certainly was misplaced. And after some 70 years in the earth, it seems highly doubtful that the primer remained intact. The other aspect is that even if the round were ignited, the most that could happen would be a low-order detonation with no chamber to contain the pressure. Sign me: Ordies R Us.