I once watched two older guys (perhaps even older than I am now) "sight in" their rifles at the local range before big game season. One had an open-sighted lever-action, and the other a scoped bolt.
Their technique was to pile up scrap 2x4's on the bench, then rest the barrels of their rifles on the stack. They were shooting at 25 yards, the long-advised technique for getting close to zero before shooting at 100. I never saw a group under 4" at 25, with most more like buckshot patterns. They were still whacking away at 25 when I left.
