I think that 22 Mag ammunition has gotten better over the past five or ten years. I have 350 CCI Maxi Mags here. I sorted 250 by rim thickness tonight and I'll test some next week. Random versus sorted.
250 cartridges
1. 3/250 - 1.2% (44.0)
2. 68/250 - 27.2% (45.0 to 45.5)
3. 168/250 - 67.2% (46.0 to 46.5)
4. 11/250 - 4.4% (47.0 to 37.5)