Oh, im playing with a new 25-06. Formed some brass off 30-06 cause I heard you could. Stuffing them with 57gr of imr 4350. The load groups about .6" when I do my part. I tried the load in some new 25-06 hornady brass i bought, the hornady brass is 125fps slow, and an inch lower than the fed / rem mix. Also the weatherby / howa has a 6" vertical shift with & without the dead air primal.
Also messed with a cortina v3 tuner on my 223 heavy varmit, it shifted groups around but didn't noticeably improve them. That being said it's a new barrel & i don't have a ton of data on the rig. Initial results were not dramatic.