Hey guys need some help.  Need some recommendations on carbon arrows for a 75# @ 28 inch robertson purist longbow. Bow is cut about 1/8" off of center.

Thanks!
Nate

do you know which carbon you want to shoot?How long is your arrow,and how much weight do you prefer up front?I don't shoot a bow that heavy but you will need a heavy spined arrow such as a 340 eastin 350 heritage etc. or even heavier for starters.

You didn't state your weight at draw (unless it is 28") or how much weight you want up front (e.g. 125 grains or 225 grains)

GT 7595 with .300 spine or GT Big Game 100 with .280 spine... depending on length and head weight you want.  
You can hand load some mamma jamma high FOC with the GT Big Game 100s.  That is bad medicene.

I use both with my setup.

7595's are .340 spine.

JimB,
I was referring to the traditional 7595s that I use..they are .300 spine

I would go with .300 deflection if your going to put any weight on the front for hunting