In 80s I did extensive tests with American made 22Lr ammo. The purpose being to show that buying match grade ammo to hunt small game with run of the mill rifles was a waste. A good selection of popular 22 rifles were used. All shot from rest with 4x scopes. Certain rifles like certain ammo, no big surprise. Remember this is in 1980s and all US made 22s were tested from premium to bulk packed. Only Winchester Wildcats were inaccurate across the board.
I just watched a YouTube video of a test made for same purpose, from different angle.
The test was made with a 10/22 and Marlin 60, fired offhand open sights. A Chrony was used and the actual deviation in velocity was recorded. It was a good bit and the match ammo was no better than standard. The groups fired off hand didn’t allow for a good comparison.
The bottom line is that today’s rimfire ammo looks to me like the QC has drifted. I had large supply of 22lr from pre panic days. The little amount of new ammo I’ve shot has produced many duds, hang fires and groups 2 to 3 times the groups from old test. The original worst ammo in 1980s tests, Winchester Wildcats, were due to powder charges.
When firing in semi auto they sounded like a posse was firing different guns. No failure from priming compound. When I say no failures with any rimfire means if there was any it was a fluke not ongoing problem.