I was reciently involved in instructing our departments newly formed Patrol Rifle Program. We had 77 students fire in the neighborhood of 53 k rounds of Winchester Q3131 and about 2 K of Q3131A.
Rifles were 16" Bushmasters. I was present on the firing line for all 5 two-day classes.
Out of all rounds fired, I am only aware of only 5 bad rounds of ammunition. We would have between 2-3 K open and out of the box, but the bad rounds appeared to come out of the same case.
Of the 5 bad rounds, 4 had a slightly crushed case mouth which protruded just enough to prevent the round from fully seating into the chamber. One round had what can only be described as the shoulder being "squished" abit, causing the unfired round to get stuck in the chamber.
Over the years, our department has used various types of training ammunition, especially in 9mm. Our staff is always in contact with other agencies Firearms Training staff from around the country. All agree that EVERY manufacture can at times let ammunition slip through the QA process. The average citizen shooter might never see it. A department ordering 1 million plus rounds a year probably will.
I still would recommend the Winchester Q3131 ammunition. To have only 5 bad rounds out of about 55,000 is pretty good. It was as accurate as could be expected, more accurate than many of the shooters were.
Just my .02 worth,
Beat Trash