with the frame a pivotable camming lever is attached to the frame and pivots in response to impact from the bolt carrier the camming lever provides sufficient mechanical advantage to enable the forward impact of the low mass bolt assembly to depress the disconnect lever on the original weapon a conversion barrel is provided and a floating chamber is also provided to enhance the recoil power of the low caliber round application_number US 40184482 A description illustrated in fig1 is a weapon 11 of the submachine gun or machine pistol type the weapon is characterized by a frame 13 supporting receiver section 14 which includes a barrel 15 usually with a bore 38 or 45 caliber the barrel 15 is provided with a breech portion 16 the weapon 11 also includes a magazine housing 17 into which is disposed a magazine 19 with an associated spring 20 a trigger 21 is provided pivotally mounted to a pin 23 secured to the frame 13 the weapon 11 also includes a bolt 25 slideably mounted within the receiver 14 the bolt 25 is provided with a centrally disposed cavity 29 into which the barrel 15 is disposed when the bolt 25 is in its uncocked position the bolt 25 is biased to the uncocked position by a recoil spring 31 disposed about a rod 33 which is received within a cylindrical opening in the bolt 25 so that the rod 33 is slideably coupled to the bolt 25 a handle 35 is pivotally connected to the bolt 25.