OP, I did exactly what you are proposing with my No.1 in 450-400 NE. Unfortunately I am not at home right now and do not have my exact data. However I followed the procedure Lennie suggested and paired the Trail Boss with a 210gr. jacketed pistol bullet. I believe I got about 1750 fps and it shot like a dream - very consistent & accurate, low recoil and report.
This combo was just plain fun to shoot. I used it as preparation for a buff hunt - scoped and unscoped, off sticks . off hand, trying for quick follow up shots, etc. I was able to do a lot of practicing without developing a flinch and at a much more reasonable cost. It made transitioning and proficiency to full power loads a breeze.
