Individual results with an individual gun do not tell us much about the average of quality of that type of gun manufactured. Pick any respected product and you will, with a little research, find folks who had bad luck with that product. No manufacturer is immune from the occasional lemon. Cooper is a respected gun maker that by and large produces a very good product.
With all that said, I had the bad luck to come up with a lemon in my purchase of a Jackson Squirrel made in 2012. I purchased the gun second hand from an older man who was selling it at the Tulsa gun show. The gun had very nice wood, had box and papers, and looked ANIB. Close inspection showed little wear to the bolt mechanism. Since I had always wanted a Cooper and since the price was reasonable I purchased it. First test firing off my bench at fifty yards yielded the results below:
To say I was disappointed is an understatement...very poor accuracy and a lot of failure to fire incidents. Before someone mentions I needed better ammo or that I needed to practice more, I will say that I have been shooting off the bench for over forty years, and have won my share of matches. As to the ammo, all lots shown above gave good performance out of my Winchesters, Anschtuz, and CZ rifles. I was certainly hoping the Cooper would shoot at least as well as this little CZ 452 FS shooting mid grade ammo - all five shot groups:
But I didn't give up, I tried some lots of Eley match and some Midas +:
No joy. After much investigating I finally figured out the following problems:
a) the floorplate was inletted into the stock too far forward resulting in misalignment of the action screws and the barreled action. When tightened, this put abnormal stress on action and screws.
b) the firing pin was too short and the the bolt had excess headspace resulting in poor strikes and the ftf incidents.
c) when slugged, the bore opened up slightly at the muzzle....not a good thing.
There were some other issues, but the ones listed above easily explained the poor accuracy. I corrected the short firing pin with a new one and corrected the headspace. This resulted in an improvement in accuracy to the point where many folks might have been satisfied with it.....but not me.
The reason I was prompted to post here is due to the discussion about test targets and because of the test target that came with my gun:
I can't imagine how they got that gun to fire that test target considering everything that was wrong with the gun. I'm convinced the gun came that way from the factory based on it's near pristine condition when I purchased it. As I said, Cooper makes some excellent firearms, and I have no beef with the fact that I got a lemon....it happens. I would definitely try another JSR under the right circumstances. Bad luck on that gun though.
But I'll leave it to you to explain how that gun left the factory with that test target.