Long story short, before 41F I the first timer submitted a few Form 1's. I have come to the realization that I may have entered the wrong info under Model in the "Line Item" section. My rifle is a Colt 6920. Under the model, I entered in LE6920. My received is stamped M4 CARBINE, and I realize this is what was should have been entered. My application is still in review. My question is, am I able to submit the change prior to review for approval? I have already sent in 3 emails to the "ask the experts" and have received no response. What are my next steps?

Wait.  If it gets approved you're good to go.  If it doesn't you'll have to resubmit under the current rules.  You don't have any other options at the moment.

ask the experts is about the only thing you can do. if they aren't responding to that, not much else you can do.

damn, thanks for the input guys

I did something similar a few months ago.  Fortunately I caught the mistake and withdrew the application before submitting another.