Webbenelli m4 magazine extension tubes. A benelli m4 magazine extension tube is the perfect way to increase the capacity of your benelli m4 from the standard four rounds to. Webjun 5, 2024 · shell tactical benelli m4 extension tubes. The first upgrade most people do to their benelli m4 is upgrade the magazine tube from 5 rounds to 7 rounds. Webmay 27, 2022 · the rx arms benelli m4 magazine extension is for those m4 owners who do not wish to perform the tasks needed to swap out their oem benelli m4 magazine.