I want to start casting and try paper patching. I just want to get started without a lot of expense. Can I use a mold that is normally for using a gas check and still get acceptable accuracy? I intend to use a Mosin Nagant with a .312 bore. Will this mold be ok for learning? http://www.grafs.com/retail/catalog/product/productId/7799 This link talks of the check, http://www.midwayusa.com/viewProduct/?productNumber=107571 .