I AM AN ENGLISH TEACHER!!
Actually, I'm teaching an AP English 10 class right now, and guess what my students are working on? Their research paper. My students have to research the bio of a famous author, however. I'll give you a simple piece of advice: Get thee to a library.
Like every other 10th grade HS student, you only know your way around the internet. That ain't research [notice the use of the colloquial "ain't" in order to emphasize ignorance, here]. Good information has been published. Any goob can type info into the internet.
The good news is that your average librarian is a lonely soul who gains personal satisfaction from showing lost mortals the intricacies of her arcane bibliographical system. If properly sweet-talked (NOT pestered with demands and treated like some type of second-class citizen) a librarian will show you to databases of magazine articles, non-fiction histories of weapons and small arms, and yearly publications of various gun aficionadoes.
I'll make one small suggestion: AK-47 vs. AR-15 is a pissing match, and not a good topic for an English research paper. However, the evolution of the modern assault-style rifle from the full battle rifles of WWII would be an excellent analytical paper, with copious amounts of available data.
Now if you don't get an A, I'm taking this as a personal insult as an Arfcommer and English Teacher.