Popular YouTube channel “Long Range Shooters of Utah, LLC” has a huge number of videos up, nearly all dedicated to, you guessed it, shooting at long ranges.
One of their most popular series of videos details the building, then shooting of an extremely accurate AR-15, an SPR variant.
While the first three videos cover parts selection and assembly, the fourth covers test firing. Finally, we get the below video, which is the first real accuracy testing at 1000 yards.
LRSoU-LLC has a ton of footage of really impressive shooting, well worth a browse through in your down time.