As I've posted elsewhere on CGN, backyard BB gun shooting competitions, started with a restored air rifle butnow involving Red Ryders and pistols, have in fact brought much fun to Bad family long weekend get togethers. Much fun had.
EDIT: I think I have worked out what happened: the Crosman involved in this case was not a 'Vigilante" but rather their model SNR357 dual ammo in which BBs are loaded into the tips of otherwise hollow or bored out dummy cartridges, as seen in the photo. Having actually witnessed it happen, I imagine the interiors of those cartridges will act as combustion chambers creating dieseling if the wrong oil is used. Beyond posting this, I have no interest in defending what I saw, nor any reason to, now.