You're not the only one that's had accuracy problems with their 500 recently, but there are also a bunch of us that they shoot very well for, not fantastic, but you should be able to get 2" groups at 100yrs with it, that's what mine does with handloads. Make sure you've read the Handi 101 Basics , if you're good to go there and are still having problems, I'd contact H&R and ask that it be repaired, or just call em and make arrangements now, be sure to ask em to cover return shipping since it's a new gun, ask for a free trigger job while it's there if the trigger is over about 3½lbs.
Good luck,
Tim