No the end of the world, but if you bought a jeep and it was only 3 wheel drive you would want to find out if there was a fix, most of the time it's no bother but when you need it then ( do some 10 round competitions) then it's handy to have.

would opening the lips up slightly increase the size slightly as only amm or so off being able to get the 10th round in. Or would that mess up with the magazine feed?

had same in .308 with ppu. Bit tight closing bolt of new rounds. Once fired, trimmed and reloaded the problem went. No problem with other brands.

says 10 round mag in adverts.  :-