I renewed my CR this year. They sent the form and I mailed it out with check ASAP. This was two months prior to renewal, check was processed and I did nothing for two months. On the last day before it expired I look at my form and noticed I filled in an answer wrong. (Stupid mistake) I called and talked to the agent in charge of my case. I ask him if my renewal was being held because my answer was incorrect. Turn out they had lost my form. Found my form, corrected answer, and in thirty minutes processed my background check with no loss of CR. This was done on a Friday, late afternoon with no time left and I received my FFL on Tuesday of the next week dated on the renewal date. After this experience , This is what I learned.
1 If your check is processed you are in the system. This I believe is the best indicator, after all they lost my form.
1 BE Civil. After you get by the front office, they are as nice to you as you are to them.
2 Do not wait till the last minute to call, if this happens again I will call a week or so before if it is not sent to me.
3. They handle ALL forms by HAND and do misplaced forms. This last year they processed the most license request than ever before. My form was in a box next to the trash can.
4 IF THEY DO NOT PROCESS YOU FORM IN A TIMELY MATTER BECAUSE OF THEIR FAULT THEY WILL NOTIFY, IF YOU REQUEST, THE PROPER AUTHORITIES NEEDED AND DATE YOUR FFL BEFORE THE EXPIRATION DATE.
Typical timing for renewal notice is about two months ahead. As noted above you must request that they notify!
I do not need mine for the Class III I own, but I think this will answer your questions.
Good Luck!