At Just BB Guns, we stock a huge range of Airsoft Guns. Made famous for its role in real-life combat scenarios, the M4 assault rifle serves as one of the most popular inspirations for the best airsoft guns on the market. Like their namesake, these guns are powerful and practical. Below are our selection of M4 airsoft assault rifles complete with RIS – Rail Interface Systems. This adds an extra level of versatility to your gun, so it can be customised with accessories for nearly any occasion. Curious about the M4 RIS works? Feel free to contact our expert Just BB Guns staff via this website with any questions. See also our wider BB Guns range for more.