Given your preferred arrow length, I'm assuming you have a DL of 28 inches or less. That being the case, the 400s are likely too stiff for your set up. Certainly for the 45# range. Even for 50# bows, you would likely need at 250- 300 grains up front. 500s would work better, and even then you may need a fairly heavy front end.
Back when I shot Axis 500 carbons they were cut to 29" I ran a 75gr brass insert with a 145 point I shot that arrow out of both Longbows and Recurved in draw weight 46 to 51 pounds they shot prefect. I had to play with the brace height.