Sell it. I was in the exact same situation 1 year ago. I am also in college, I am 21 now. I was low on money back then and to be honest, didn't think I wanted an AR-15 till way later.

I came up with the idea of selling the 15-22 (And my gamo whisper air rifle) and using the money top buy a Rock River AR-15 and getting a .22 conversion bolt later to give me that AR in .22 that I still loved. I could not have made a better decision.

I now run my stainless steel CMMG .22 conversion in my AR with a Taccom Buffer, and 15-22 mag adapter so I can use those good old 15-22 mags in my AR with the conversion. It runs flawlessly. Any problems I have had had been failure to fires (bad primers).

In my specific AR with the heavy profile barrel, I got the same accuracy I did with the 15-22, about 3moa with CCI Blazers at 100 yards. A lot of people will bring in twist rate. 3moa is 3moa to me. If accuracy is there, I'm fine with it.

Also, if I could do it all over again, I would build a rifle to how I like it configured. My rock river is barely a rock river anymore. I sold and swapped parts.

Good luck!