I'm tuning some arrows for my blacktail Elite, im drawing29" bow is 47# @28. I'm trying to tune some arrows for it right now. Currently I'm trying to shoot 31 1/4 400 spine with 275 up front. Am I close in anyone's opinion or should I give some 500 a try ?....Gary

I would guess with that length and that point weight, .400 spine would be in the ballpark.  With a 47# Bob Lee recurve that I draw to 28", arrows cut to 29", and 200 grains up front I use .500 spine shafts.  The extra length and point weight would probably push you up to .400. Fortunately, you have a little extra length to trim if you need to.