This is an answer to a question I received to help calrify the Benelli M4 Shell Release Lever.
No problem, Although, I am fairly new to guns, and I am not an expert at all. I enjoy sharing my limited experience.
The Benelli M4 has a “free carrier” This means that the bolt and carrier can work independently of the magazine. Because of this you can keep your magazine full of say 00 buck and load and shoot a different shell say maybe a slug, or bird shot, when the need arises.
For example, if the shotgun is loaded and ready and you decide to change the shell in the chamber, all you do is pull the bolt lever back to extract the shell. When you do this the magazine does not release another round. If this was a Remington 1100, then it would release another round onto the carrier because the bolt, carrier, and magazine are all working together as a system. You couldn’t easily insert a different shell into the chamber like you can with the Benelli M4.
With the M4 the magazine does not release another shell onto the carrier. The magazine only releases a shell when the shotgun is fired, then it does it automatically, or when the shell release lever is depressed.
I believe that all the Benelli Super 90 shotguns have this same free carrier feature to allow you to change the round in the chamber without using the magazine. This provides great versatility in allowing you to match the ammo to the target and situation.
So, the shell release lever does two things:
1. It releases a shell from the magazine. Depress the shell release lever and a round is released from the magazine onto the carrier.
2. It locks the bolt back when the magazine is empty. Depress the shell release lever, Pull the bolt all the way rearward, If the magazine is empty then the bolt locks back in the open position. It only locks back with no shells in the magazine, otherwise it releases a round from the magazine when depressed.
Note: If you pull the bolt back without depressing the shell release lever then the bolt will not lock open.
Note: when firing the shotgun in semi-auto mode, the bolt locks open when the last round is fired and the magazine is empty.