Alan

Try this. After shooting with the rifle still on your shoulder hit the lever with your thumb. pull barrels down as you rotate to the inside over 90 degrees to allow shells to fall out on ground. Push new cartridges, that you have between your fingers, into chambers backhanded. (have the cartridges between your fingers with bullets toward the back of your hand) As you push in new cartridges rotate rifle back to vertical and close action with your left hand. Rifle is ready to shoot.

I have seen good shooters do 4 aimed rounds in 5 seconds. I think it could be faster but takes allot of practice.