3 Rivers Archery offers a test kit for 20 dollars. This is from their website...
"This Gamegetter XX75 test kit offers you the chance to "test drive" 500, 400, 340, and 300 grain aluminum shafts.
Gamegetter gives you the best of both worlds with a state-of-the-art aluminum shaft that blends strength, flexibility, and affordability into a knock-out package!
If you've been shooting aluminum shafts, then you'll still be able to pick your favorite size. 500=2016 (10.6 grains per inch). 400=2117 (12 grains per inch). 340=2315 (11.7 grains per inch). 300=2317 (13.3 grains per inch)."
I'm not promoting any business here, but this might be a good way to find the proper aluminum shaft for you.