...do you mean a bare receiver? Receiver blank would be a solid chunk of chrome moly or stainless steel.
Sometimes distributors have offered actions only, but there's really no point. With the price of a base model 700 or Savage (or Stevens at ~300 bucks), just buy the rifle, sell the stock and barrel new unfired, and be sitting pretty with a ~$200-400 action. Just pick a cal people will be after, ie. not .308, or .22-250 etc. Get a 1/9" .223 for small bolt face, or a .260 or 7mm-08 for medium, etc, those barrels sell.