ARROW WEIGHT

I'm shooting an st.axis arrow right now the spine is 500.I told the guy when i bought the bow i thought the arrow was under spine but he's said it's fine he's the pro.I been doing alot of reading on this everything i been finding is saying i should be at 340 or 400 spine arrow.Is this a big deal?I just think a 362 grain arrow is to light for hunting.