I am currently having an issue with an RIA 1911 nose dive jamming. That is posted in another thread.
The issue here is the ammunition I was using yesterday during testing seems to have a problem.
I was using Federal 115gr 9mm FMJ aluminum cases brand new from the factory. When one of these does the nose dive and I clear the gun, the bullet is being pushed substantially deeper into the case. Sometimes as much as .135 inches. The average being about .060 inches.
My reloads with either bullets or cast does not do that.
This is going to cause an over pressure issue. I am just not certain how much. I am not going to shoot these shortened bullets and will pull them apart but this is an issue that I believe is specific to this particular case. It appears the aluminum case doesn't hold the bullets as well as brass does.
My point being, if you are using this ammunition and have a jam of some sort, make sure to check the cartridge to see if it has been shortened to a dangerous degree.