I havn't bought a new Handi lately, but have shot some good 223"s, one just a sporter barrel that shot great with 52-55 gr, it was the older twist. Then the 1-9's shot well too, well some of them with 68-69 gr.
So, if the Handi has a 1x7 or a 1x8 twist now, it is news to me. But, with so many Handi guys responding and no mention of twist, I guess it got by me perhaps.
It's common knowledge that the 1-9 is too slow with the 77 grain. Sierra says the following: "With this cartridge, we recommend a 1x10 as a minimum for the 69 Matchking, and a 1x8 for 77 & 80 grain Matchkings". I personally have never seen a twist slower than 1x8 shoot the 77SMK well at 223 velocities.
My RRA AR shoots the 77SMK better than any other bullet.