That is almost impossible. I have not seen a 25 or 26 inch bat that does not say T-ball. 25 and 26 inch bats are for t-ball. My son is playing machine pitch and has the Rawlings Quatro 26 inch t-ball bat. We are using a hard ball and the bat has been great. We do a lot of hitting outside of games and practice and the bat has held up well. It is the most expensive USA t-ball bat out there, but it has a big barrel and is very light weight. It has a lot of pop and hits the ball pretty far. I read something online one time that said if you can use a larger size barrel why wouldn't you. So I suggest getting the larger barrel bat.
That's what I have found as well. Hope they reconsider rules - forcing 5u and small 6u kids to swing a 27 inch bat is silly. Anyone know of another organization that does not allow 5u and 6u to use USA bats stamped T-Ball even if hitting a normal baseball?