With a twist rate that fast you won't be able to load the hornet to its full potential, but you should easily be able to match 22 mag speeds with 55 - 60 gr. bullets.
Some hornets are easy to achieve very good accuracy with cast bullets, others aren't. It all comes down to the chamber and throat design, SAAMI Hornet chambers don't really have a throat and are difficult to work with. Hornet chambers like Thompson Center cut have a nice throat design and can really be made to sing with lead.
So, make a cast of what you actually have and that will tell you what bullet design you should be looking for. With that fast twist you could shoot up to 70gr. with no problem so you will have a pretty good variety of mould designs to choose from. Of course if this is a magazine fed rifle you'll be limited by overall length if you want to use it as a repeater so keep that in mind as well.