Never thought you play with a gun but
It’s pleasing, at least you can feel something
The burning of your flesh hits your nose now you’re bumping
Doin’ that grind all of the time
Someone will getcha, know they’ll out betcha
Swipe away your dime find your bottom line
You’re using anything that comes your way here today
Gone tomorrow all about beg, steal and borrow
Can’t stop, won’t stop ’til there’s nothing left but sorrow
You’re cruisin’ don’t even care about what your losing
You’re using anything that comes your way here today
Gone tomorrow all about beg, steal and borrow
Can’t stop, won’t stop ’til there’s nothing left but sorrow
Shot by your own device you paid the price so you give in
To the pity party, party of one, no one shows up
Another sip of poison slow death fills your cup
Your arms feel tied down and you can’t understand
When you try to stand up your legs have other plans
Oh man, damn, you can’t get out of this jam
You’re using anything that comes your way here today
Gone tomorrow all about beg, steal and borrow
Can’t stop, won’t stop ’til there’s nothing left but sorrow
You’re cruisin’ don’t even care about what your losing
You’re using anything that comes your way here today
Gone tomorrow all about beg, steal and borrow
Can’t stop, won’t stop ’til there’s nothing left but sorrow

Its about just living for today and not for tomorrow. The subject is partying/living an objectable lifestyle without a care in the world, abusing himself and it eventually will catch up with you is the message. Lots of times karma is a theme 311 uses and believes in and it comes in to play here. Nick said it best "when the day is done what you receive is the sum of what you put in from what you took out".

My interpretation was that this song is about a drug dealer who has started using his own drugs. (Mainly because of the lines "When you are dealing Back spinning wheels And doing that grind All of the time", which I interpreted as dealing)
And the suggestion that he has started using his own stash:- ("Shot by your own device You pay the price")
I'm not sure what is meant by "The burning of your flesh hits your nose, Now you're bumping"; I know 'bumping' is a slang term for snorting drugs through your nose, but I'm not sure what is causing flesh to burn (Maybe I'm trying to interpret this too literally?)
The multiple references to a "Gun" I'm still wondering about. Is the gun a literal gun (i.e. a handgun/weapon), or a reference to a syringe for injection of drugs?
The song title "Rock On" may refer to "rock" (i.e. Methamphetamine), or it may be a coincidence.