They raised it last year to .54 for elk. I'm sure they feel that requiring open sights would limit long shots. Little did they know what goes through the minds of hunters.
I don't see 300yards as being MUCH a problem, Pete. When Taylor built my .69, we put a 3-leaf express sight on it. The last leaf was filed for out 300 yard gong, which was 30" round.
That rifle had no trouble hitting that plate, offhand by all of the guys who tried. I could never get anyone to fire a second shot, though, 165gr. 2F does kick a bit. LB hit it, as well as Taylor
and Neil too, iirc. It was not much of a trick- fair hold and sight picture with the front bead - boom*************************clang.
At our Blackwater range, we have 14" x 16" AR500 plates hanging at 20, 300, 385 and 500 metres. I have hit the 300 meter (328.1yards) plate with my 14 bore rifle several times and even
managed that with a .577 M1861 Enfield with patched round balls.
Being able to use actual sights set for THAT range helps immensely.
Thus, trajectory becomes less of a problem - it does, however, reduce the height of the target due to the descending angle of the 'shot'.