If you have credit card debt...pay it OFF. Don't get stuck in the trap of paying those high interest rates. In fact, even if the interest were zero forever (will never happen), it is unwise to owe on things you have already purchased (and in many cases, already consumed like food, clothing, gas, etc.).
Why would you want to take out an 19.8% loan on a $25 meal at Chili's and pay it out over 12 months?!?!? That's what you do when you have credit card debt.
The .50BMG will not increase in price at the same rate as your credit card debts...so pay it off!!!!!!!! You'll feel the monkey slip off your back when you do. How can you plan for retirement when you aren't paying THIS month's bills off?
Once cards are paid off, buy the .50!!! Your son is old enough to buy his own toys!