Mahindra 7520, Mahindra 3215HST, Case 580 extendahoe, Case 310 dozer, Parsons trencher, Cat D6,
You may want to post your question in the Kubota forum instead of the Kioti forum. You could also probably take a look at the Kubota website and find out there.
0.49 cu ft or about 0.18 cu yards sounds about right, a heaping scoop is probably a little closer to a 1/4 yard.
For comparison, the CK20 KL120 with a 50" bucket is rated at 5.56 cu.ft (0.21 cu yds) and 7.76 cu ft (0.29 cu yds) heaped. So around about a 1/4 yard per scoop.