Twist rate of Howa heavy barrel varminter .223?

Here is the best way to find out without asking the company that made it. Take your cleaning rod and get a tight fitting jag with cotton patch. Mark your rod with a piece of tape with one dot on the tape to track what position your rod is in. Then run the rod down the barrel until you see the dot do a full 1 revolution. Put a piece of tape on the rod where the end of the barrel was when the full revolution completed and then withdraw the rod. Measure the rod's distance from the tape mark to the jag's contact point and then you will know your twist rate per inches. So if your rod traveled 9 inches down your barrel from the muzzle before it rotated once then its a 1 for 9 inch twist.