H&R is just now switching over to 1:9" twist rate on all .223 barrels except the fluted model which became 1:9" last year sometime. If your rifle was made in 2005 or earlier, in will probably have a 1:12" twist rate, look in the FAQ to find out how to check mfr date and also how to check your twist rate. That said, the Winchester whitebox ammo shoots great in either twist rate, so give it a try, $14 for 40 at Walmart, less at other sources.
Tim