Where can you find a breech bolt assmebly for a marlin 22 model 15Ys?

You can find a breech bolt assembly for a Marlin 22 Model 15Y at several places, including online retailers specializing in firearm parts, such as MidwayUSA or Numrich Gun Parts. Additionally, you might check with local gun shops or gunsmiths who may have access to spare parts or can order them for you. Online auction sites like eBay may also have listings for used parts. Always ensure that any parts you purchase are compatible with your specific model.