This is for tubular magazine rifles with a loading gate on the right side.
For right handed shooters. After firing the last round, open the action ejecting the last empty case. With your right hand, quickly insert a live round into the open action and close the action. Keeping the rifle horizontal and pointing forward, with your hand positioned to fire at any moment, turn the rifle so the loading port is facing up. Using the left hand, select a new round and insert it half way into the magazine. Take another new round and insert it half way. Half way is easier on the thumb and quicker. Repeat until the magazine is topped off. Push the last round all the way in. Return the rifle to the upright position. If you have to fire with a round half way in the magazine, use the fingers on the left hand to swipe the half way cartridge out of the loading gate before cycling the action.
For left handed shooters. After firing the last round, open the action, using the right hand, quickly insert a live round into the open action and close the action. Keeping the rifle vertical and pointing forward with your hand positioned to fire at any moment, the loading gate will be facing to the right, use the right hand to insert a new round half way into the magazine. Take another new round and insert it half way into the magazine. Half way is easier on the thumb and quicker. Repeat until the magazine is topped off. Push the last round all the way in. If you have to fire with a round half way into the magazine, use the right hand (or right thumb) to swipe the half way cartridge out of the loading gate before cycling the action.
Learn to do this without looking at the loading gate. Keep your eyes up looking for threats. This will also aid you in reloading in low or no light conditions.
David had some comments on the video I selected to accompany his article:
The video is good, especially if you are a competition shooter like that guy is, armed with a highly modified rifle. I like the 1873 Winchester. His has a modified lever that operates with half the distance required from an un-modified rifle. It’s called a lever kit.
The Cowboy only mentions that one modification of the lifter. Not the others. My method works with all of the modern lever guns. My article is specific to rifles with a loading gate.