Here's what will happen:
If you are caught, you might be arrested or you might be cited into court. If you are arrested, you will probably want to bond out, which will either tie up your money or cost you 10% of the face amount of the bond for a bondsman to post it. Then you'll go to court, at least once. The weapon will be forfeited. Guarantee that, so I'd recommend that you not test my prediction with an expensive gun.
If you are lucky, you will face only expungeable probation, but that depends if you have a record already. If you can't get the expungeable probation, you'll have a weapons conviction for life. Either way, you're looking at court costs of hundreds of dollars and probation fees on top of that. Absent the expungement, likely you will be unable to purchase weapons or get a permit in the future, and it will be a problem on background checks for jobs, housing, credit, etc.
Get a permit.