It depends what his rap sheet is and how much time he has done in the past. If he is on probation, he has a probation violation case in addition to the new charge.
You don't really ask a question, but the only real response anyone here can give your boyfriend is to remain silent about the facts surrounding his case, meaning do not talk to anyone other than a criminal defense attorney, and then actually speak with a defense attorney. Most offer free consultations including myself. If he canno afford a private attorney he should request a public defender.
Michel& Associates, PC
All my comments here are intended for general legal purposes. None of my comments here establish an attorney-client relationship with anyone. None of my comments should be relied on in taking legal action without first consulting an attorney.
There are several aggravating factors you mention that make it difficult for anyone to give you a realistic idea of what your boyfriend is facing at this time. The best advice we can give you is to speak with a criminal defense attorney you trust and believe in.
Was the "modified" shotgut "sawed-off"? If so, this modification (for concealment) makes the gun illegal for ANYONE to possess, let alone a felon on probation. The one bright spot in the case I suppose is that he is off parole.
Best of luck.