Holly cow Fritz, there are lots of light arrows out there. If you want a 400 spine you could look at the Easton Lightspeed at 7.41 gr/inch or the 340 at 8.1/inch. Top this off with a target point and get rid of the insert, fletch with feathers and you're near a dryfire situation. 500's are definitely too limber. The way I figure it a 28" 400 with 70gr tip and three 4" feathers with uni-nock would weigh just about 300gr. Light enough for ya?