re:
Several reasons why they chopped 1911 variants tend to be finicky, and some of those things can't be "engineered out" with any consistency. Physics are still physics and mass is still mass...and springs...even though they have a singular purpose...still work in both directions.
The recoil spring's purpose is accelerating the slide...not decelerating it. Whatever else it happens to do is incidental and irrelevant.
The instant the slide starts to move forward, outside forces are at work trying to stop it. Those forces must be overcome in order to provide reliable feed and return to battery. That's the basic operating principle of the self-loading pistol. Firing, and setting itself up to fire again. Everything that happens between those two events is no more than a series of needful functions aimed at firing and automatically resetting the gun.
In order to overcome those outside forces, a certain amount of momentum is required. When mass is reduced, the velocity must be increased in order to provide that momentum. Heavy springs are the only source of that velocity.
The problem is that springs work in both directions, and heavier springs work to decelerate the slide...and the heavier the spring, the more rapidly it decelerates, making a firm grip on the gun more critical. The slide's rearward travel is already compromised. If the slide doesn't make full travel...even by a fraction of an inch...it may not uncover the next round, and a rideover misfeed or a stovepipe failure to eject is the likely result.
The shorter travel and runup makes magazine function more critical. If the magazine spring isn't up to the task of getting the round to feeding position in time to meet the slide...a bolt-over base misfeed is in the offing with the lower rounds. Upping the magazine spring's rate usually solves that issue, but at the expense of higher drag on the slide in recoil on the top rounds.
On the issue of increased slide velocity rearward and the concerns of frame damage...that's just so much sheep dip. Propaganda from people who make money selling springs and shock buffs. There is so little difference in slide to frame impact between a 5-inch gun and a Commander...and between a Commander and an Officer's Model...that it can be ignored for all practical purposes.
Remember mass and momentum. The slide impacts the frame with its mass and its conserved momentum. Lower mass and higher speeds are really neither here nor there. The impact momentum is the same...even with equal spring rates...and even with no spring at all.
Assuming equal outside force, the slide's momentum is equal to the bullet's. Assuming equal ammunition, the momentums of the different slides are theoretically equal...regardless of their velocity. In actuality, the shorter slides have less momentum than the 5-inch slides because the bullet's velocity is reduced...and so is its momentum. The slide's momentum can't be greater than the bullet's. One is moving a little faster at impact. The other carries greater mass. Flip a coin.
