I've shot Beman MFX Classics out of my Savannah for the last two years...they've also flown out of my Bacote Kill-um.
The most experience I have with them is out of my Savannah...50 @ 29" pulled to around 29.5" and the arrows are 30.5" long and I shoot 145 grain points with the standard adaptors. They fly great and total out just shy of 500 grains.
400 spine MFX classics will need a 100 grain brass adaptor and about 200 grain points if not closer to 250 grains for a total of 300-350 grains upfront and close to 625 grains fully loaded.
I've shot the Beman Black Max (same as the wood grain just without the wood grain
) and they are also great. GPI are a touch lighter but they fly the same and hit the same…that being said I think the wood grain (Classic’s) are a touch tougher and will last a bit longer.
For your weight and draw I’d suggest starting with the 500 spine MFX with about 150 to 175 up front and the normal adaptors you might get away with 200 grain points. They are a very stiff arrow by nature. Your draw length and overall arrow length is going to stiffen them up a lot. Plus remember the arrow is micro dia and the arrow will be stiffer if your bow isn’t cut to center, arrow point isn’t as far out to begin with.
Hope this helps…I just started playing around with my new Kajika Stik 55 @ 29” and they love 400 spine arrows with 200 grain points and 100 grain adaptors, total arrow weight is 605 grains. They just flat out shoot great. I got a wild hair up my keister and built three Beman MFX Classic 340’s…they weigh 726 grains total. 250 grain point, 100 grain adaptor and the arrows are 31” long, they’ll knock the target over and fly amazing with 24% FOC.
Sorry rambling on...
Josh