well since when reloading the smoke charges we have to get the smoke shells from behind the commanders turret.. where the batteries are located for that specific part.. and if it is as normal.. the driver would have alot of his gear stored along with the commander in those boxes so to get the shells for the smoke launchers do take a little bit of time.. regarding the 35mm rounds once youve shot your 35 rounds per mag. you have to slew the turret 90 degrees to each side, all depending on what magasine you want to refill.. and since reloading of the magasines can only happen from the infantry compartment it takes time.. all the ammunition is stored under the turret.. so since the infantry that sits there is all cramped up theyd have to do the refilling of the mags. where you pull the shells out in a band of 7 rounds, and continuesly attach them to eachother as you feed the 35 rounds back into the magasine. and that bit takes time... plus if you didnt have infantry in the back it normally falls to the driver to sort out the magasine refilling. if you want more info give a shout.. and sry if it doesnt make all sense to you.. but i tried to make it understandable.. and if possible ill take pictures to explain further...