Boy, this thread sure has gotten slow after grauhanen got snowed out of his range for the season

Do y'all remember this jovial fellow?
I got my tuner back from being bored out for my barrel just after Christmas, and today was decent enough to go out and test it, 3C calm winds but foggy. Got my ammo order last week with more Lapua Polar Biathlon, some SK Biathlon Sport, SK Rifle Match, SK Standard Plus, and a couple tins of SK Magazine (great "bulk" ammo

). I used the Purdy PRX to set the tuner for the 7th harmonic, being setting 273 on my Harrell's tuner with a heavy weight ring attached. First couple targets I explored above and below the calculated setting, since it is just a starting point and one cannot expect to be in tune at the calculated setting, but it should get you in the zone + or - 30 clicks in either direction. After shooting 275 rounds I settled on setting 268 and proceeded to thoroughly vet this setting. I was not disappointed.
Rifle: CZ 455, Custom Lilja 3-groove straight 0.850" 24" barrel, Boyd's Pro-Varmint stock, Fly Trigger
Scope: Leupold Competition 45x, EGW 0 MOA rail, Burris Signature High rings
Ammo: SK Biathlon Sport
Caldwell Rock front rest, medium front bag, Caldwell rear bag
Groups: 0.293", 0.349", 0.278", 0.186", 0.349", 0.322", 0.338", 0.312", 0.395", 0.271", 0.205", 0.254", 0.376", 0.394", 0.395", 0.269", 0.291", 0.353", 0.384", 0.307"
20 group average = 0.316"
Yeah, I'd say it shoots 1/2" all day.
The inside of the red circle is 0.480" for reference
Well, I didn't get the 25 groups demanded by alberta guy, but it's pretty obvious after 20 groups that there ain't no "getting lucky" on this target. Come spring once the temps are above 10C, and North Sylva gets more RWS R-50 in stock, I have ambitions of getting this rifle into the 1/4" club. This wasn't bad for cold weather shooting with mid-low grade training ammo, but I'm sure I can get it doing better. I'm not even sure it's properly tuned yet, maybe it'd be better at a different setting, or perhaps the 9th harmonic instead of the 7th I used? More weight, less weight? So many variables to test, but the rifle definitely would not have done this without the tuner, no way, no how.