From what I have read, every addition of 30 grains of arrow weight reduces the speed of the arrow by 10 f.p.s. That would put you right around 26 f.p.s. loss from the gain in arrow weight. That would put you at 280 f.p.s. That extra 1/2 inch of draw length isn' t going to add much speed, a couple feet per second. Well, then, you add in your string accessories, and you are right on track. Heck, you might be exceeding the expected performance of your bow at that set-up.