To quote a great man.....and it applies to 1911 mags very much.
It only matters if it does.
Many 1911s will feed from essentially any magazine. Others need a specific type.
A root part of the problem is that most guns that we are familiar with have only been made by one company, the
company that invented the design. The 1911 has been in production for over a century and there are currently
about 20-25 different companies turning out their version of the design. Many have DESIGN changes included, and
I will bet that very few are built to the original blueprints, unchanged.
So, "A 1911" isn't "a 1911" --- it is a Kimber or a Colt or a S&W or a Ruger, etc.
This complicates things. And the fact that there are three separate, grossly different styles of magazines, with
at least 20 different styles (many WILDLY different) of followers, and most of them were NOT designed by the
gun designer.
What could possibly give you inconsistent results from that?
I have had excellent results for decades with the Metalform mags with this kind of
follower.
But then again, most of my 1911s are not particularly picky about mags.Only my carry Colt Commander tells me it wants original Browning design (GI style) mags.
Bill