Although I have read in other places on this forum that the "Bushmaster Semi Automatic rifle" is some other "Bushmaster Semi Automatic rifle", there is no specific model or designation, or any other description. I know very little about the law, but IMHO, that sure sounds like a broad category. And given the way that these A$$HOLES in Analpolis (I borrowed that from someone else...) interpret the law... well... you be the Judge.
EDIT: OK... I type slow too... thank you for the clarification.
it's banned because all AR-15's and their copies are banned, not because of the copycat features
and we are not discussing loopholes until after the session is over
I think the notarized affidavit is a good idea if you don't have the receipt, or maybe even if you do have it. That is probably what I will be doing. It certainly can't hurt anything. Just state on the affidavit that you legally possessed serial number such and such before the effective date of the Firearms Safety Act of 2013 and call it a day. Call the form a "Firearms Affidavit" and get it notarized.