\ You're calculating incorrectly... If you have 200K arrows and pick up 150K from the accumulator, you still have 150K arrows left then multiplied by .75 etc. Using a sequential equation Use of n = Use of n-1 * .75 Use of 0 = 200K we can use an equation finding how many shots you would have taken after you let's say repeat this process 10 times. So... 250000((.75^11)-1) / -0.25 = 958K Yes, that seems "right".