Ignition Tumbler/Key Confusion

[Ian Mills]

I recently purchased a 2005 Silverado 1500 and it came with two keys (both well used) that appear to be perfectly identical. However, one of them always turns the ignition with no issues and one of them turns the ignition only after wiggling it for several seconds. 

There must be some imperceptible difference between the keys but I'm trying to decide if it's more likely a bad key or an ignition tumbler that's at the end of its life. I know they're both pretty cheap fixes but I was wondering if anyone has any insight

[Jwd5k]

so ignition key would not turn so i worked it and made it turn to get truck home  so I removed the tumbler and bought new one had locksmith come out and set my code and reinstall but now it will turn and all accessories come on but engine won't turn over engine and key doesn't have the spring back when trying to start it  i did notice a long spring in consol now but not sure where it goes i can remote start the truck then use key to turn on accessories  but key won't start truck