Don't be so quick to dismiss your 12 gauge. I bought one an 11-87 with a cantilevered barrel for turkey. I got a rifled choke in case I wanted to use it for deer. After I mounted a scope I took it to the range. I decided to shoot some old-fashioned rifled slugs before shooting some much more expensive sabots. They cloverleafed at 50 yards. They did great to 100, the maximum at my club. In the field the gun has never failed me. I have taken deer to 100 yards with it.
Now I am not dismissing the sabots. But I am not sure the extra money is worth it. A few bucks a box is a lot cheaper than 10 or 12 bucks a box. You may be better served by using your money to shoot more.