I generally figure I'll have one or two fails within a box/bag of 50, no matter what brand, until I get to premium brass like Norma, Nosler, Lapua... For Win, Rem, Starline, Top Brass, etc, I figure on a couple percent as failure - but I do NOT figure on a "few" percent as failures.
I will say - I'm disappointed in Winchester's processes for customer service. Their service is great, but their processes are silly. I found a bad batch of Winchester 243win brass, I had bought 2 bags, and out of 100 pieces, 57 of them had problems with the flash holes. One additional piece had a crumpled shoulder, and another was badly enough gouged such I wouldn't feel safe loading it, so a full 59 out of 100 of them were defective. I returned to the store and examined the other 3 bags they had - same lot LF41 - and even through the clear window, I could see several of the flash holes had the same issue. I found more of the same lot at another store in a different state - more of the same issue.
So I called Winchester, they sent me a return mailing authorization, and agreed they'd fully refund my costs... And here's where my problem with their process starts... They said the refund would be a physical check, mailed 2-3wks after receipt of the returned brass. So we're talking a MONTH to refund my expense. I would have rather had them send me new brass anyway, and I certainly would have preferred to NOT take a full month to rectify the problem.
It's 2017 - mailing a physical check and taking a full month to process a return just doesn't make sense.