OK, so here's a couple of targets I've posted before:

Best of three 50-yard groups I shot with a Wilkes-made Manton .470 during my first 'regulating' session immediately after purchase:

Third 50-yard group shot with Scott-made Rodda .577/.500 No.2 during pre-purchase test-shoot:

Group made with the Rodda following bore-scrub:

Note that these are 2 touching pairs of right-and-left. The first pair from the newly-cleaned barrels went lower than the second and subsequent pairs.
Slight crossing evident, which was cured by crimping.

Here's the winning target in the 2005 Australian National Double Rifle Championship (despite the flyer!), made with my Jeffery .450/.400: