Tinker, the 300 yard or meter full-bore competition target is useable for irons out to that range. I have used 12" square painted black sheets of paper to 450 yards with the buffalo rifle to good effect.
: I use old forestry maps (reversed) for the backing.
: It is amazing what one can do at long range with iron sights, if one had the audacity to practise at long range.
: At 300 meters (328yards) at the local range, the 2/3rds size ram was a 5 for 5 offhand with all shots striking in an 8" circle. This would have been A-OK on 5 moose at that range, considering the .375 H&H Ruger #1 I was using. On the other hand,it was practise only. My personal range limit on moose is much closer. Too many bad things can happen as the trigger is being sqeezed - wind, movement, other animals not observed, etc.