There's a pretty good chart at www.arrowsbykelly.com . It goes up to 80@31, and still hasn't gotten to a 2315.

It's been along time since I've shot aluminum, but off the top of my head you might need a 2016, or in that range. Your string, nock fit, release, bow performance, how far off center the shelf is cut, etc. will all make a difference.

This is just a guess, but seems to me the person at the store was just trying to get rid of some shafts that don't sell.

Chad