Airsoft Chay takes a look at the Maruyama ISO 556, an airsoft replica of the B&T APC556. The replica features a 6061 extruded CNC aluminum upper and a polymer lower. According to him, The controls are accurately replicated, and the fire control group is mostly steel. It uses VFC M4 magazines and is compatible with other VFC mags. The replica performed well in cold temperatures and is accurate, with an adjustable hop-up. Pros include its accurate replica design, well-made externals, mostly steel fire control group, good gas efficiency, and accuracy. Cons include a weak recoil spring, no included NPAS, and potential import requirements to the US. 

Overall, he recommends it as a unique and well-built gas blowback rifle.