Hi! I'm Brian, I am a live audio visual production specialist, and I will be assisting you today.Unfortunately, the mount on the D3300 is completely different and is not compatible with the older FG lenses. I have seen converters that would allow you to use these lenses; however, I have never liked the quality when using these adapters, and they often cause problems with the newer cameras since the newer cameras are expecting to see certain electronic systems in the newer lenses (such as focus, stabilization, etc) that were not available in the older lenses. In many cases, you have to "hack" the new camera and trick it into releasing the shutter, since it does not like to release unless it can sense a lens is attached (and it can not detect the older lenses).I'm sorry I couldn't have better news for you! :(
Hugh, my name is***** am only a hobbyist photographer who works part time in a photography shop, I do have 30+ years of experience. I have to disagree with Brian's assessment. The FG camera uses type AI lenses (manual focus lenses with Aperture Indexing levers). These can be used on any D-SLR with few exceptions. In general, the higher end D-SLR's (such as the D5, D4(S), D3X, D3, D810(A), D800(E), D750, D700, D610, D600, D500, D300S, D300, D200, D2 and D1- series cameras) can meter with these lenses, but when used on the consumer cameras ( D5300, D5200, D5100, D5000, D3300, D3200, D3100, D3000, D80, D70, D60, D40, and D40X) the user will need to determine and set the exposure manually.
I am unable to verify at this time the type of lenses used by the Nikon 2000 series camera, but if it is indeed an AI lens like that on the FG, then yes, it can be used on the D3300, but again, you'll need to determine and set exposure manually.
You can read more about Nikon lens compatibility here:
I hope I’ve provided the information you were seeking. If I have, please kindly take a moment to rate my service, so I will receive credit for my answer. If you are not satisfied, please let me know so I can continue working with you or refer you to another expert. Please do not issue a rating until you have provided me with an opportunity to address any remaining questions or issues. Your complete satisfaction is my goal!