With factory ammo only, I would doubt you will see much improvement in accuracy with a different barrel. If you reload, then you would likely get better accuracy from any barrel from load development and testing.
One option you did not state, was testing more brands of factory ammo in with your current barrel. My CZ, with the heavy varmint barrel, likes the Federal American Eagle 20 grain more that Hornady 20 Vmax. I know some insist those are both made by Hornady, and they might be, but perhaps to slightly different specifications, and not identically produced. There is also Winchester, which my buddy's Savage likes better than Hornady 20 also. I know it will be virtually impossible to get all three brands to test, but eventually you should try them all. Even from lot to lot of the same ammo, it varies, so that might be a factor to keep in mind. If you find a brand and load of factory it likes, see if you could buy a volume of it of the same production lot.
Reloading the 17 Hornet is not an easy "starter" project in my experience. It's picky, and you have to be very precise on charge weights and seating depth, primer selection, brass prep. Some insist you must neck turn the Hornet brass (only brand available of unfired brass), so sticking with factory offerings makes sense if you don't want to invest in the equipment and learning curve. Though it's nearly impossible to get any 17 Hornet ammo, (or brass, or primers, for that matter) right now.
If you've got the funds to change, sounds like a fun idea. If it were me, I'd try my best to figure out exactly how well my current barrel shoots, under ideal condition (little to no wind, solid bench rest, decent temperature, yadda yadda) and test with the Hornady, Federal and Winchester brands. You might be happily surprised that one of those 3 shoots better than the rest, and give you tiny little groups.
And after you get the new barrel, and do a little break-in, then try to test under the same "best conditions" as the factory barrel, and see if you actually have more accuracy with any of the three brands. You'll want to know which of the factory ammo shoots best from your new barrel also, so you can buy what it likes. If you have a real nice new barrel, and ammo it doesn't like, it would be a waste of money without the full benefit. Which is what you apparently are seeking, reaching its full potential.
