Hello, My stepfather gifted me an AMT hardballer a few years ago. It came inoperable. Every piece was there except the barrel (it came with a springfield style 1911 barrel..) I ordered an auto drop colt style 1911 barrel and it should be here today. My main concern is assembling this gun and shooting it. Since I have never shot this gun before are there any concerns I should have? I have also never installed a new part before, though I know how too, is there anything I should know about installing new parts?