nevermid: magically opened. Just took much longer than instructions. Thanks anyways!
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One of the tricks is to cook them in pot or pan enough to hold them and permit a lid to fit. Add moisture in the form of water broth or wine and get that up to heat. Add the clams, cover and if there is sufficient steam they should open in under 3 minutes depnding on the size of the clam. Cockles open real quickly but a littleneck might take longer.