if your tax return showed that you had say $40,000 in income from a job, and you 'made' another $1000 buying and selling guns, then as a percentage, the 'gun income' is a very small percentage of your overall income.
Including the sale of guns from your C&R collection as income on your taxes? WOW never heard of that one. If you do, you are basically admitting you are selling guns as a business, and therefore acting as a dealer. Which is not allowed by a C&R licensee.