Here's what I have against factory ammo, last fall I had a guy call me and was convinced his 300 win. Mag had a problem he said it was shooting great but now it would only shoot 2" groups at 100. I told him to bring his gun and ammo I would have a look at it. He comes to my shop I look it over can't find anything wrong, so I set up a target at 100 and told him to shoot a group sure enough about 2" hes frustrated shows me on his phone where sure enough could put 3 you could cover with a dime at 100 with the same ammo, hornady 180 gr. I believe there superformance ammo. Then he tells me a couple days ago he was trying a different scope and he got a sticky bolt lift after he shot a round, I told him wait a minute let me set up my chrono before he shoots again. He fires a round 3175 fps!! I told him there's your sticky bolt lift I was expecting 3000 + for factory he let's another round go 3075. *** 100fps difference so I told him there's nothing wrong with his gun hes got an ammo issue. He said he had just bought 2 more boxes before he came up so I told him I wanted to look at his empty cases he had just shot he handed me the whole box of ammo I was looking for flat primers and lo and behold in that box of 20 there was 3 with brass colored primers and the rest silver. I told him that's B.S he said he had the other box in his car he went and got it and in that box there were 6 brass colored primers and the rest silver. Needless to say he was furious and was taking the ammo back were he bought it from think he said he paid 68.00 a box for it.
He didn't have any idea how much primers made a difference until I went got 3 rounds of the cheap 180 gr Remington core lok ammo and he shot those into a 5/8 inch group.
I guess if that's quality ammo then so be it.
My point is when you walk into a store and buy factory ammo you have no idea something has changed until you go through something like this guy did, that's why I started loading my own 30+ years ago.