Fast, Low poundage bow?

[HATCHCHASER]

I shot a 432 grain arrow.  Gold tip 55/75 full length and 125 grain head, at 200 fps.  A 510 grain arrow averaged 190.  The 654 grain arrows were too stiff and did not fly good out of my bow I was shooting them to see what they did.  THis is all out of the same chrono.  I had to bend at the waist and squat in an awkward position to get through the chrono staight.  That being said, many factors play into arrow speed.  The tightness of nocks, brace height, which mine is about 8.25, release.  You may have a better release than me which is highly probable.  Sounds to me like your bow is as efficient as any but the one that you shoot best will kill best.