I have not shot one for a long time but as I remember them, they are good performers.
One suggestion is to make sure you are not short stroking the lever. Make sure you get full travel.
Sometimes they work better when you work the action forcefully. Don't try to ease the next round in. Eject the spent one and work the action with authority.
Some semi auto pistols act the same way when you try to baby them by easing the first round from a magazine.
Did you clean out the factory oil before you started?
I am really surprised you are having issues.
Have you cycled the action to see if there are any rough spots?