Did you start ammo selection on a new barrel, or did you "season" the barrel with a certain number of rounds before selecting your preferred ammo?
If you started on a new barrel, have you retested any of the ammo you rejected to see if it shoots differently?
Started with a new rifle.
Put 200 rounds through it just to see how it shot, and get the scope, etc sorted. Used SK Rifle Match and Eley Club. Both shot to same POA so that was OK.
Put another few 100 rounds SK and some RWS through to season the barrel (well I just used what I had and shot lots of practice rounds while I decided what front rest, rear bag, etc I wanted)...but I do clean the barrel about the 50-60 rounds mark. I'm ex military and I like a clean barrel!
Had a few fliers with the SK, and a few FTF with the Eley Club. The RWS Rifle match was fine...but then could find no more here in NZ.
The SK would shoot fine but the odd flier ruined a few targets for me. Could actually hear the difference in the 'bang' as the shot fired. So the ammo is not consistent (but what .22 ammo really is?).
The Club I sorted by doing the firing pin mod, and polishing the firing pin flat surfaces. Polished the bolt including all the little inlets, grooves, etc.
The bolt is so slick now it feels like it runs on well oiled rollers.
The Eley Club was my main ammo for just over a year but still I felt I could do better (I'm retired so I'm not into buying Tenex at nearly $NZ40 per box).
The Club was adequate for the start of my benchrest adventure (I have shot a lot of prone but got too old to get down on the floor and get back up again!).
So...enter the Norma Tac-22. Tried it, shot a 100.2, thought that's OK, and have now many times shot 100+ with the Tac-22 ammo.
Could do that now and then with Club but not target after target.
Have now sold my stock of Club, and SK ammo and just kept the Tac-22 and a few remaining boxes of RWS.
So yes, seasoned the barrel with Club and SK.
Continued shooting both up until a few months ago when the Tac-22 became available locally.
I held the Club round up beside the Tac-22 round and my eyesight tells me that the Club has a slimmer nose profile. The Tac-22 looks to be 'fatter' at the nose.
But could be 76 year old eyesight of course. I think the Tac-22 is a different profile anyway, and my rifle likes it.
Now I have used the bolt shims it's possible that the Club would be fine in my rifle (if I added another 2 thou shim maybe would help?).
I have fine tuned my gear too of course. Slicked up a Farley co-axial 2 front rest with UHMW tape and low friction grease. Made a better rear bag slider.
Little by little I am inching to that 100.10 (10 shots dead centre) and it's not all about the ammo.