There always is chargeback risk even in person buying with Chip+Pin Visa/MC cards. If somebody enterprising wanted to do Visa->Bitcoin they would have to:
Get chargeback insurance protectionhttp://www.cashrun.com/prodsolutions/cashshield
Sell Bitcoin as a commodity/good instead of 'currency' so Visa/Mc don't blacklist you
Keep $10k in liquid funds lying around to instantly buy coins while waiting the 3-7 days for the payment gateway to settle funds to your bank, or have a ton of coins you're willing to speculate on and hope they don't drop in price to $2/ea again
Cap it at $40 or something per transactions
Use a service like this to dropship a registered code in the mail for further protection, if taking over $40 or so, or ship 'paper coins' to them, or something you think up like a printed login to get coins out of an online wallethttp://www.send-certified-mail.com/
You would have to charge at least 10% to make any profit from this, and no doubt gamblers would make your life hell constantly charging back, claiming their kids bought the coins or some other lies to screw you.
If you live in Ukraine/CIS you can use Liqpay.com to sell Bitcoin (if you advertise it as gaming commodity) but lately even a $60 charge from any card that isn't issued in CIS they take forever to authorize. The gold companies selling up to $5k in gold have plenty of insurance, and they're also ripping the customer off so they make extra money.. look up Glen Beck's old touted company that was shilling supposedly rare gold coins at 4x the price before the feds seized it.
Bitinstant is such a good service credit cards no longer needed. Now somebody needs to clone their system in Europe/Asia/Uk
Also DGC companies in Canada sell LR for Amex/Discover at a decent price, but Visa/MC is 22% and up