This is an extremely old cartridge originally loaded with black powder. Little has changed during its life and still many potential problems related to accuracy still exist. Users of this ammunition are totally at the mercy of the ammunition factories unless careful measurements and sorting are accomplished. Measuring and sorting require specialized tools and much dedication. Many think this is unnecessary and can be avoided by purchasing high end and costly brands. They are perhaps lucky, but wrong and at risk.
I own a Winchester model 52C with a bull barrel that I have had since high school. It is mostly a factory rifle with a glass bedded wood stock, Canjar 2 oz. trigger and a 2″ Unteral 36X Ultra Target scope. Originally it was equipped with Redfield Olympic and International Globe sights. It has never liked anything but Eley. The gun is capable of under 1/4″ groups at 50 yards. More than once I have had a flyer ruin a perfect group. Until I started sorting. Even with the best Eley, I can afford, I always found 1-3 different cartridges in a brick/case of 500. Appears these always showed up at a match. Now when I make a bad shot, it’s usually me or the wind and not an inconsistent or different cartridge. This is a big confidence builder in my equipment and it’s worth the effort.
My measuring and weighing tools evolved when I purchased several boxed of the highest-rated and costly 22LR ammunition I could find. I wanted to find out why they shot better. My research resulted in only one thing “CONSISTENCY”. But there was more, specific weights and dimensions were more accurate than others. Once I found the best performing ammunition for my target rifle, there was still an occasional flier or short round. So again I went after the answer. Even with the best ammunition, I found, sometimes there was one or two that were different. Identifying these and test firing them against the consistent rounds displayed there was always a problem. Not so much for the average shooter, but too much for the match competitor. Even if the cartridges weigh and are of the same size, they may not be the best for your firearm. It is a tedious task, but a surprise at a match can be avoided. Your other option is $0.40 per shot, trusting the manufacture and hoping for no surprises.
For years I have wondered about the claim that Eley Tenex has about “Patented flat nose bullet”. For those like me that cast and shoot lead bullets know that flat-nosed bullets are more accurate than round or sharp-pointed bullets at lower velocities The great 1958 Lyman Handbook of Cast Bullets displays hundreds of flat-nosed bullets I have not read the patent, but perhaps it pertains only to 22-40 grain target bullets. For over a hundred years flat-nosed bullets have been the standard for accurate target shooting. Why aren’t they adapted by other manufacturers? Flat nosed bullets are not reliable for feeding in semi-automatics, but is rapid-fire more important than accuracy?