Uintah Precision produces the only true bolt-action, precision upper receiver. Compatible with LR-308 and AR-15 platform rifles, UPR-10 and UPR-15 bolt action uppers simply pin in place of your existing upper receiver, with no modifications or changes made to your lower receiver. Available in most popular calibers available in both platforms, and feeding from standard magazines, Uintah Precision bolt action uppers are perfect for hunting, long range precision shooting and competition. This year Uintah Precision debuts their complete true bolt action AR rifles. Accurate Modular Familiar (less)