When I was planning my AR308 build I wanted a vise block for it. Ended up ordering one via eBay (new) seeing it listed as 7.62 but didn't realize it was for an SKS. Cost me almost the purchase price in shipping and restocking so it isn't worth it. Free to anyone willing to come pick it up (east of Hutch) or pay for actual postage.
Tapco 16797 Armorer's 7.62x39mm Magazine Vice Block Polymer
BB