Re: New to this, but
No idea of the best one for 223.
It's not a license, it's a tax. 200 dollars may or may not be "that bad", but yeah, I think 600 dollars (which is about what a high-powered rifle can would cost) is kinda high.
No, you don't need to tell ATF anything, unless you moving to another state. There is a form for "temporarily exporting to another state", like when you go to another state to a match, or something like that. That's required for machine guns and SBS or SBR, but not for AOW or silencer. ATF "suggests" you get one for any NFA, but there is no law saying you have to. If your question is, "I'm gonna go out and shoot it - do I need to tell ATF?", no you don't. Carry your paperwork. Actually, make copies of your paperwork, and put the original away safely. Carry a copy with you whenever you take it out. Legally, you are only required to show your paperwork to an ATF agent. If your local town cop/deputy sheriff/state trooper/FBI guy thinks it's illegal, and wants to see your paperwork, legally you can tell them to take a long walk on a short pier. Realistically, however, they will then arrest you and you will stay arrested until you can prove it is legal by showing them your paperwork, so might as well have a copy with you whenever you take the can out.
Meddle not in the affairs of dragons, for thou art crunchy, and taste good with catsup - George of Lod, Year of Our Lord 297
I always take precautions.
Beware the Evil Bullet Fairies.