The recoil spring is probably one of the most-often cussed and discussed
parts of the 1911 pistol, next to the extractor. Fails to go to battery? Stick a stronger spring in it. Short cycles? Stick a weaker spring in it. Worried about frame and slide damage? Stick a stronger spring in it. Limp-wrist malfunctions? Stick a weaker spring in it....ad nauseum...and folks would go around changin' springs willy-nilly because somebody told them that it would
make the gun "better"...and they did it without considering exactly what that spring does, and how it does it. The plain simple truth is that the gun was designed around a 16.5 pound recoil spring...or less. Get too far removed from that, and you're changing the timing of the slide.

Springs work both ways. Stronger slows the slide going backward, but speeds it up as it returns to battery. Move it too fast, and the slide will
outrun the magazine...usually on the last round or two. Weaker slows it
down forward, but lets the slide smack the frame harder in recoil. No
free lunches. Speaking strictly as to reliability, it's generally better to
underspring the slide than to overspring it. The feed/return to battery
phase of the cycle is pretty complex and consists of stripping a round from the magazine, pushing it up the feed ramp, getting the case rim under the extractor, breaking the round over to horizontal, and chambering the round.
All that takes time...The faster the slide moves, the less time the other parts have to perform their function. Timing! Timing!

The recoil phase is much simpler. All the slide has to do is travel
fully rearward with enough force to knock the case off the extractor hook
and kick it free of the port. Most pistols will do that with 25 or 30% more
recoil spring than "standard", given a firm grip on the gun and standard ammunition.

Overspringing the slide makes the magazine timing and function more critical. It gives the round less time to get under the extractor hook. It sometimes knocks the round ahead of the extractor, effecting a push-feed and forcing the extractor to climb the rim instead of getting it under it...and this ruins extractors PDQ. Overspringing also makes the gun more grip-sensitive. Other factors come into play with a gun that is prone to limp-grip malfunctions, but the recoil spring is the main one.

If the gun won't go fully to battery without overspringing it, there's something else wrong. It should go to battery reliably with a 10-pound spring. The gun should cycle reliably through a full magazine with the loosest grip that you can manage without the gun flying out of your hand.
If it won't...get it fixed.

The recoil spring has very little, if any, effect on the unlock timing of the barrel. The barrel and slide move rearward for a short distance...about one tenth of an inch.. before the barrel STARTS to unlock. By the time the spring has any real effect, the bullet is gone. Momentum completes the unlocking phase and carries the slide through the recoil cycle. The spring
that has the most effect on the initial movement of the slide and barrel is the mainspring. Unlock timing is also affected by the shape...the amount of radius...on the bottom of the firing pin stop. A smaller radius there
decreases the mechanical advantage of the slide against the hammer...
and increases the force necessary to compress the mainspring. You
can effect a slower, gentler recoil cycle by simply using a different radius on the firing pin stop with no other changes. The original design used
a firing pin stop with a very small radius at the bottom. It was changed
at the behest of the military to make the slide easier to rack with the hammer down...because the Army required that the gun be carried in Condition 2 until action was iminent. I suspect that before the change, the recoil spring was likely in the neighborhood of 13.5 to 14 pounds too...

Using a stronger recoil spring to offset frame to slide damage and wear is
counterproductive. It does reduce the impact shock in recoil, but it does so at the expense of the lower barrel lug and slidestop crosspin. The lower lug feet and slidestop pin absorb the brunt of the slide going to battery. Those feet are small. The slide's impact surface in the frame is much more able to withstand the shock than the barrel lug. You're not delaying breakage with a stiffer recoil spring...You're only changing where the gun will break. Neither are
you changing the amount of time of the complete cycle...You're just changing
the dwell time from one direction to another. The difference in total time, if any...will be so tiny as to be of no consequence.

John Browning worked out those spring rates carefully, and he really did know what he was doing. If everybody would just bear that fact in mind, the undeserved reputation for spotty reliability with the pistol would virtually
disappear. Of course...that would put many aftermarket parts suppliers
out of business...and several gunsmiths would feel the brunt as well. When
I was in the smithin' business...by far, the biggest volume of my work was
reliability tuning. Most of the time, reliability was returned to a problem child by returning the gun to original design parameters. I can't recall how many "Jammin' Jennies" that I've "fixed" by using a good magazine or spring, installing a lighter recoil spring and/or a standard 23# mainspring.

The occasional extractor tweak, and cleaning the guns properly also
brought them into line most of the time. Sometimes the guns came back with the same old problems...Why? Because the owner had decided that the slide was too easy to rack, and installed a stronger recoil spring. I'd stick a 16-pound spring in the gun and hand it back to him with the suggestion that he go out back and try it. When the test-fire session was done with no stoppages, I'd charge for the spring and advise that it be left alone. Some did...Some didn't. Ah well...

Remember the Cardinal Rule: Changing one thing rarely affects just one area. Anything that CAN be affected by the change WILL be affected
to some degree.

Cheers!

Tuner

Bravo, Tuner! I am tempted to post this message on several other "bulletin boards" where I have been reviled for advocating the use of lower powered recoil springs, but they don't deserve it. Let them suffer their own ignorance. BTW I have a .45 ACP Devel Gammon built by the late Charlie Kelsie. He used an over powered main spring and a bull barrel/comp which allowed the use of an eight lb spring for target loads and an 11 lb spring for bowling pins. The pistol has digested over 125,000 rounds with no apparent wear on the reciprocating parts.

1911 Turner,

Just read your post. Great knowledgable post. Thanks for the info.

I just dropped the spring weight in my Para P-16/.40 from 12lb to 10lb. After about 600 rounds the verdict is that muzzle flip is reduced and the shock buff is still in good shape. This is using IPSC Major (165 pf) loads. The gun is fitted with a Nowlin bull barrel which I believe retards the rearward motion of the slide, allowing the use of a light spring.