Obviously, be sure to declare it, but once you do, watch your luggage get extra special treatment – apparently it’ll be handled extra carefully, won’t get lost, and will be the first on the carousel.
However, we REALLY don't recommend doing this without knowing the local legislation. If you happen to end up in a state with strict gun laws (like New York, California, Hawaii, and Illinois), you could end up going to jail.
6. Acquire shopping bags. Avoid overweight fees
Go to any airport gift shop and ask for a big shopping bag. Then throw all your extra crap in there, and strut on board; since it looks like you just bought this stuff, airlines can’t charge you for an extra carry on.
Alternatively, look into whether buying a cheap new bag and checking it as a second bag ends up being cheaper than paying overweight fees. If so, do that.