A different version of the JM Model is the JM.DB Model, which is the only model in the world with a double barrel technique. The standard model JM.DB is delivered with 11mm and 13mm barrels. It is easy to interchange the 11mm barrel (for 1.5 and 3.0ml darts) and the 13mm barrel (for 5.0 and … Continue reading Co2 Injection Rifle Model JM DB 13