I recently (April) purchased 4 magazines directly from CZ.
Last week, I was loading up a few magazines with my carry ammo, when one of the feed lips broke along the length of the feed lip. I contacted CZ Warranty Support, and received this reply...
"We have an updated polymer that we started using about 4 months ago and we have eliminated the stress fracture issues. I can Only exchange out your damaged mags but not the other ones you have that aren?t broken. So if by chance the feed lips on your other magazines break before you send them in then I can replace them as well. Let me know if you have further questions."
I told them I found it interesting that just two months ago I ordered these magazines from CZ, and now find they changed the polymer four months ago to correct this issue, but are still sending out potentially defective products.
So - they DO have a issue with these mags, but they seem to be willing to replace any that have a problem. I plan to have several load/unload session this week to see if others will have issues.
Happy Monday,
Bob S.