Many guns will tolerate the hybrids well, but fewer are fully happy with the parallell lip mags, or at least
I can tell a difference in feed smoothness with dummy rounds and no spring, hand cycling the action.
But there are a bunch of 1911s out there that will feed dead reliably from pretty much any of the modern,
decently made, lip shapes. A tribute to the guns, that so many will run with way wrong mag lip setups, which
are unfortunately pretty much the standard these days.
Interesting side note....a friend has a Springfield Armory (modern) 1911 that he won in a match some years
ago which has always been a PITA feeder, but it is in 9mm. We recently took this one as a project. Examination
showed that the mags he has, the high build quality Bill Wilson mags are pure parallel feed lip designs, and some
other brand (I forget the brand right now) had much earlier release point. All of them jammed quite frequently,
and my first comment was the unkind.....'so wadda ya expect from 9mm in a gun designed for .45?" Of course, others
have had 9mm that ran fine in the 1911. I took one of the Wilson parallel lip mags and very carefully refiled the lips
to a long tapered, rising round design, more like the original 1911 GI mag lip shapes.
This let the round (tapered round, too) come up quite a bit, maybe 1/8th inch over the travel from full rear to where
it pops out of the lips. This mod fed 40 rds flawlessly in initial testing. Too little to prove much, but a definite good trend
when it wouldn't get a full mag clean before.
I was heading back to the origin JMB concept of controlled round feed and rising cartridge.
An added screwup factor is that the tapered rounds want to curve as they are stacked, so in a straight mag, they
tilt nose down. The second round in the mags are way clear of the first round, except at the base, so little support
for the feeding round to not nosedive, which is what it was doing. Letting the round rise as it came forward let it
hit the feed ramp much higher and it went up and in, not down and stop.
My friend was going to run a lot more ammo through it and then try his hand at filing another one of the Wilson
mags to match the one I did.
Bill