In the [test report of 2004][1] according to Ursack:

> Bears carried inadequately-secured Ursacks short distances suggesting that users should be able to locate most bags that might get carried off by bears. Distances carried during the four tests were 0.3m, 1.6 m, 5.8 m, and somewhere between 41 and 67 m.

In those cases, the sack did prevent the bear from getting to the food in the sack.