Simply put, no maker can account for ALL the possible variables in every gun, everywhere.
That's true best everyone can do is try to stick to standards, not load light, and try to stick to a reasonable set of bullet profiles for target use.
some of the calibers date back so old they did not account for the wild JHP profiles on the market today (9mm, 45acp). I've heard of 1911's that choked on anything but G.I ball, and others that could load empty cases (impressive)
New guns I think account for defense rounds even if the gun in question is of older origin.
-My personal philosophy is 300 flawless rounds of FMJ + 100 flawless carry ammo, then it's suitable for carry.
Some will say 4-500 rounds of carry ammo but that gets expensive quick (I know whats my life worth right?)
Magazines are marked and tracked for malfs, usually no more then 3 mags
I may have more mags but they're kept for reserve use.
Often the mag can be the problem so marking your mags is very important imo
I will rotate which mag is carry in the gun after range trips.
I will also say try to use good quality mags, if not factory then Mec-gar is my goto trusted brand.
If you go cheap then give it extra scrutiny before you trust it.
This is just what makes "ME" feel comfortable with a new gun, ymmv