If 250 is the minimum amount of developer needed, and you're diluting 1:3 you need a tank that can hold 1 L, otherwise the film doesn't have enough developer available.
If the tank only holds 295 ml, there is not enough developer available to do the job, even though the ratio of what's there is 1:3.

To the OP, what are you looking to accomplish with the 1:3 dilution?