Abstract: A radiation curable coating composition that includes from about 5 to about 70% by weight of the reaction product of i) one or more polyisocyanates, where at least 10 equivalent percent of the isocyanate groups are in the form of uretdione groups, and ii) one or more hydroxy functional lactone ester (meth)acrylates. The amount of component i), on an isocyanate equivalent basis, is equal to the amount of hydroxy equivalents of hydroxy containing materials in the composition. The composition can be used to coat substrates by coating at least a portion of the substrate with the above-described coating composition and subjecting the coated substrate to radiation.