I've shot several 16X cleans at 600 yards with Iron sights on a match rifle, several 14 and 15x cleans at 600 yards with a service rifle. I think your sons FIL is probably not bullish*tting.
When people face the possibility of freezing or starving there is little chance they are going to listen to unfounded claims of climate doomsday from a bunch of ultra-rich yacht sailing private jet-setting carbon-spewing hypocrite elites
