UPDATE:
Went shooting today, firing 225 rounds of Federal Champion bulk and 225 rounds of CCI AR Tactical. I had cleaned the gun last time with Eezox, wiping all excess off, and added no other lubricant. The resultant failure to ejects were:
Federal: 11 FTE
CCI: 6 FTE
So, CCI was better than Federal by almost 2:1, but even 6 FTEs in 225 rounds is IMHO way too much.
More concerning, one round when fired felt different after feeding, so I checked the bolt and saw that the bolt had not gone into battery, but was about 1/8" to 1/10" out of battery. Thank goodness I didn't pull the trigger! I ejected it, removed the mag, and inserted it back in manually. It didn't go in the full way. Releasing the slide ended up with it again 1/8" to 1/10" out of battery. I thought at the time it was one of the Federals (wanting to blame the cheaper bulk ammo), but kept the round for measuring and realized after I got home it was one of the CCIs.
I've measured the case and bullet of the round that would not go into battery, as well as others, and found that while the cases seem about the same, the bullet diameter of the round that would not go into battery was about 0.004" larger in diameter (0.227"+ vs 0.223"). And I really do NOT like the idea that the 15-22 would have fired the round that far out of battery. That bothers the hell out of me (and would have done more than that, had I fired it).
So, I've lubed with a quality lube, not over-lubed, tried quality ammo, and still have a problem. 17 FTEs in 450 rounds is not acceptable to me. Time to contact S&W?