No expert here but there are Broomhandle web sites that go into this. I bought one years ago and paid a bit more for just the pistol. I don't recommend shooting it with 45 ACP. Several sources said that it's not quite right for 45 ACP. Of course I shot mine but it acted like it was ejecting prior to enough reduction in pressure. Also, the early Chinese stocks go for $8-900 not sure about the later knock-offs, probably $4-500.