17 WSM Ammo Lots that are better/worse than others?

A lot of the issues I've seen about the BMag seem to be ammunition related. Has anyone found certain ammo lots work better or worse than others?

Been through about 6 boxes with my gun and I haven't shot any that I felt were any better than the others. They are all gonna screw your groups with a flier or two every time unfortunately. I know there are people that claim 1/2" @ 100 but I just don't see it. The gun wants to do it but the ammo won't allow it in my opinion.I have shot some nice 3 shot groups and a few nice 5 shot groups but I don't feel like that paints a true picture. I could cherry pick some impressive looking targets to brag about but the truth is that my gun is about 1 1/2" @ 100 on a good day with the ammo thats available.Wish some other manufacturers would start making ammo for this gun soon. Might take some time though.

Not necessarily with the B mag but I've had a couple of bad lots of Winchester ammo. One was the bulk pack 333s and had a lot of duds (about 15%) that wouldn't fire even though I tried them in 2 different rifles and a handgun that I'd never had problems with. seemed like a priming problem because they all had good dents but just wouldn't fire.
Then there was a box of 115gr 9mm that keyholed at 15-25 yards out of my G19. Took it across town to the G factory for a checkup and the armorer looked at me like I was crazy. Shot the same ammo out of my G17 with the same result. Whether it makes sense or not it was definitely an ammo problem.

Something else to keep in mind was when AMT blamed "ammo" for the issues with the 22 mag automags....