Look for one of the newly made Weaver "Classic" K scopes. They may have stopped making them a year or so ago, but there are alot of them out there, nib, and they are as sturdy as tanks. I think they came in 2.5 and 4 power. Very compact, very well suited to heavy recoil, so should be great for your carbine. You may have to pay $125 to $150 to get one though. I have two, on hunting rifles, and I highly recommend them.
Regards,
Mannyrock