That depends on which GT Lazer II you've got. Just weighed two different GT on my powder scale. The original GT's that came with the Vortex in spring of '07 weighs around 427 grns ( it's got a half wrap on it). Flat alum nock, 100 gr field tip and 110 gr brass insert. The ones I purchased as raw bolts late last summer and finished the same, except lacquer finished backs, weight around 400 grs. Hmmm, I though. So I took off the heads and just to be sure they weren't different weights and did it again again. Sure enough the earlier bolts weigh about 27 grns more. But since the lighter ones are my hunting arrows, that's the one I chroned. They are leaving my Vortex around 320fps and my Terminator around 315.