These days QC is suffering everywhere in just about every industry more than in the past simply because it costs less to do less and it's all about profits, especially as more and more gun companies become owned not by gun folks, but investment groups. Sometimes lack of QC is as simple as not having enough employees to do the job and make deadlines, sometimes it's a lazy/disgruntle employee, sometimes it's a rogue manager putting demands on those doing the work so they feel they cannot meet timelines unless they cut QC, sometimes it's simply the company deciding to cut it to save $.
The sad part is, manufacturers know that the vast majority of guys buying their guns, unless they are custom/super premium, probably can't shoot that well, at best might experiment with 2-3 different ammo types, doesn't handload, own a borescope or chrono, and will probably never shoot the rifle at a target longer than 100-200 yds. I still see guys every weekend at the range shooting 2-3" groups with a centerfire rifle off a road up jacket using factory ammo, and they are okay with it. Those of us that are disappointed a rifle won't shoot better than 1 MOA are still the vast minority of customers.
So when you factor all that in, you can cut a lot of corners and still not get many rifles returned, the few that you do get returned, you fix and move on.
We were talking about barrels the other day as I just had to send a new Wilson Combat 224 barrel back because the last 10" or so had what appears to be red corrosion and the gas port had chip outs / burrs in it from the factory. Now of course the corrosion could have happened after the barrel left WC, but the gas port issues sure didn't Kind of sad when you see WC's own video on barrel production where they show barrels being scoped twice, including at final inspection. There's no one way someone did that with this barrel you could feel the burrs as an obstruction to the bore scope when I looked at it. Even more interesting is they didn't replace the barrel they "brushed out the light discoloration, and cleaned up the gas port burrs". I'd be willing to bet what gets returned looks like crap.
However it's about math sadly, probably less than 1 in 100,000 gun owners owns a bore scope, even though they are now less than $100. Some break in and cleaning and maybe that barrel shoots okay for most, others might get frustrated and sell it, or trash it, but the vast majority will not be able to scope it and return it, especially when WC only has a 90 day warranty. Not to mention that most guys if they care about accuracy and don't own a borescope, they are going to buy $500 in ammo trying to find one that shoots really well in a bad barrel. So if WC sends out 100 barrels like that, instead of scrapping them, maybe they get 5-10 back tops, and if all they do is brush out the rust, and clean up the gas port and send it back out, they are $$$ ahead as opposed to making sure the barrel passed good QC standards before shipping in the first place.
The real sad part is we see tons of posts about barrels that look like crap inside, and it doesn't take long for people to come out of the woodwork and say "It doesn't matter what it looks like inside, how does it shoot?" However the bottom line is, given all things equal, a barrel that's got issues internally will never perform as well as one that doesn't. Gun manufacturers probably hate that bore scopes are now easy and cheap to obtain because it sheds a lot of light on how bad some of these barrels are internally, where 20 years ago even a lot of small gunsmiths didn't have borescopes.
