Yes - that is the one I thought of for close-range shooting, for sure, with the .222 trailing closely behind.

The 6mmBR Ackley Improved holds the record now for 600 yards, 5 shots in .282".

Seems to me, a .30 Baer on the 8x68S case set the previous 1000yard record at 1.397".
That record, placed in 2008 was beaten in 2018 by a fell ow using the same ctg. that made the 600 meter record, the 6BR AckImp.
That current record at 1000 yards is 5 shots in 1.068".