I did similar testing to get "possibilities" for most of the rimfires I've owned after my yourth of having to shoot whatever I could get on the ranch. Usually a couple of 10 shot groups from a clean barrel, sometimes more on those that looked the most promising. After narrowed to the 2-3 I'd probably be using I got more into shooting long strings to see what set in the a barrel best. Then I set about sorting the ammo by rim thickness, later sometimes even weight and concentricity as well depending on what it was going to be used for (although not the 5mm) for the best consistent accuracy. Buy rim was more than enough for even long range hunting. Sometimes I went the extra for match shooting, and I started buying rimfire ammo in very large quantities all from the same lot number. While I shot a lot of match, hunting was my game for the lions share of all the shooting I did all my life with all firearms, much of it long range. So only by rim became mostly standard on the rimfires, "my" sorted lots used accordingly for what I needed the most of for their uses. And it carried over into all the 17HMR and 17HM2 firearms as well. It was really worth the time and effort when I started buying custom barrels with custom chambers especially, but by rim helps any rimfire even with a SAAMI chamber. I saved a lot of extra cash from the "target" ammo I had been buying when I could improve almost any ammo myself, even bulk pack, and it would shoot as well or more than good enough for a fraction of the cost. I did the extra for all the cernterfire I loaded, so the RF's deserved the same to me, so did the game shot.