Hm. The CZ has a double stack, single feed, factory, 10 round magazine. This is not aftermarket modification of a M14 magazine. It is not some gunsmith fitting bottom metal from a different source to a Remington 700.
I have had to go through 4 of the magazines to get two that work reliably. Those that are reliable are very reliable, at least IME. As far as inconsistent accuracy attributable to the magazine, the rifle itself is quite accurate, and I haven't *noticed* any shift of the POI with a change of the magazine... I will keep an eye out for it.
Too, I had a Remington 40x with clip slot which accepted every clip I fed to it without complaint. I don't remember any misfeeds either, but this is when I was shooting highpower back in the 90s, and my memory is not what once it was.
I have no reason to doubt Bart B 's observations, just that it didn't happen to me. Guess I am lucky!
'Course at the time most guys shooting "match rifle" were shooting space gun AR15s. I don't remember any other bolt gunners on the line when I was shooting.