No, these were from an earlier batch of barrels that we found while moving. Those have either 1/2x36 or 9/16x24 thread pitch. In an effort to streamline our process, in the future we will only be offering Grendel barrels in 5/8x24 tpi, so we have discontinued the sale barrels. The previous barrels that we had a problem with were resolved and everything is running well again.
Jesse