I concur that there are multiple bullets in the barrel.
The full pressure of both loads never went anywhere except to the carrier key. This is the pressure that the bullet would have used to fly out the barrel, but it was corralled to your key and sheared it off.
Your barrel is not likely going to be very accurate even if you get the bullets out. The pressure that sheared off the carrier key also worked its mayhem on the inside of your barrel. I wouldn't trust it as you may have an interior bulge that hasn't quite cracked the outside of the barrel yet, but may over time.
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Ferrari 360 Specifications