I would not mention using a 405gr bullet to CVA if you ever need to call customer service. They prohibit the use of bullets over 300gr in sabots in the APEX manual.
You should easily be able to match or beat 45/70 405gr ballistics for trapdoors and get really close to 45/70 modern levergun ballistics.
Approach maximum recommended BH209 load data with a bit of caution. Pressures go up quite a bit with a 405gr bullet vs a 300gr. Start at about 90gr and work up very slowly and check your primers for signs of high pressure.
