.308 Winchester
Many Shooters will immediately recognize this as a common sniper caliber. Indeed, many military and police sharpshooters use or used this caliber.
The bullet is large and the casing is rather short, kind of the opposite of the .270, yet the ballistics are arguably better some how for the .308, despite the higher bullet/powder ratio.
The ballistics profile of this round hits the sweet spot, traveling long distances with accuracy and consistency, and it even behaves predictably in the wind.
There are hotter and heavier rounds out there. Certainly, there are trendier ones. The generations of military field-testing behind the .308 makes it unique. The US Army caps the recommended range of the .308 at 1,000 meters.
You could certainly hit a target at over that maximum reliably with the .308, however, if you were so inclined.
Photo credit: Credit: JHobb, wikimedia