U.S. gun maker Colt filed for bankruptcy protection on Sunday and has put itself up for sale in an unusual auction with an opening proposal from its current owner, Reuters reported yesterday. An affiliate of private equity firm Sciens Capital Management has proposed buying Colt Defense by assuming obligations including up to $105 million in outstanding loans and as much as $20 million in new loans, court documents filed on Monday show. The stalking-horse bid does not involve any cash and sheds $250 million in bonds. In other words, Colt would look much like it does now, only without the bonds.