Alrighty, got my MecGars today.
Factory mag spring measures .045" thick and is uniform in width throughout it's length. MecGar measures .051" and is mag width for 3/4 of the length up to the 'pinch' in the mag body. Spring feels much stronger, definitely more than the 10% Wolff spring I had years ago.
Look, my first CZ was a 75bd. It would try to extract factory FMJ while feeding a fresh round and jam on the case rim. CZ couldn't fix it, so I got some MecGars and it cleared up.
My 527 had the rounds feeding at a 45 degree angle. Turns out the mag body had burrs from an improperly designed cut. CZ sent me two new mags with the same burr and refused to listen to my fix.
The follower isn't anti-tilt, adding to the issue.
I just accept that every new CZ I buy will need 'tweaks'. No biggie, love the guns.