The Firing Line Forums - View Single Post - Had a 9mm blow the back of the cartridge out along the rim? What the heck?

noylj · October 15, 2012, 12:31 AM

Never have had a lead bullet leave a ring around the lede, other than as part of general leading problem--and never had a problem because of it.
1) Can you guarantee that that particular load had 5.0gn of 231? No chance of some powder hanging up in the powder measure, giving you a larger charge, or any chance of a loading error?
Pull the other rounds and weigh the charges.
2) If you don't know about bullet set-back, it is clear that you probably have NOT been doing the "bullet push" test. Learn it and do it, every time--very important for 9x19 and .40S&W.
3) Some cases, from almost any manufacturer, can have walls too thin and NOT hold the bullet tightly. See 2) above and trash any such cases.
4) With the gun empty, cock the hammer and dry fire. Repeat, but with the slide pulled back a little. Determine how far out of battery your gun will still fire. This could be what happened--slide just enough out of battery that the area in front of the extractor groove was more unsupported than normal.
5) What was you COL? Could your gun handle a longer COL?

October 15, 2012, 12:31 AM	#12
noylj Senior Member Join Date: October 21, 2007 Location: Between CA and NM Posts: 858	Never have had a lead bullet leave a ring around the lede, other than as part of general leading problem--and never had a problem because of it. 1) Can you guarantee that that particular load had 5.0gn of 231? No chance of some powder hanging up in the powder measure, giving you a larger charge, or any chance of a loading error? Pull the other rounds and weigh the charges. 2) If you don't know about bullet set-back, it is clear that you probably have NOT been doing the "bullet push" test. Learn it and do it, every time--very important for 9x19 and .40S&W. 3) Some cases, from almost any manufacturer, can have walls too thin and NOT hold the bullet tightly. See 2) above and trash any such cases. 4) With the gun empty, cock the hammer and dry fire. Repeat, but with the slide pulled back a little. Determine how far out of battery your gun will still fire. This could be what happened--slide just enough out of battery that the area in front of the extractor groove was more unsupported than normal. 5) What was you COL? Could your gun handle a longer COL?