1911 recoil

1911 Recoil Spring Information

Back in the day, there was only one spring for the 5-inch 1911 pistol…and it wasn’t identified by “pounds.” Neither was it the now-accepted standard 16 pound spring.

Sometime in the last 30 years, 16 pounds came to be standard, and everybody accepted that figure…because it was close enough for gub’mint work.

Then, along came Bill Wilson’s mandate that we should “tune” the gun to the load by using the strongest spring that would reliably allow the slide to lock…assuming that was an assurance of full travel rearward in recoil….which is wrong, because the slide doesn’t have to reach the impact abutment in order to line up the slidestop with the stop notch.

Not only is hitting the impact abutment an important part of the function, it has to hit hard enough to rebound and give the slide a jump start. If all there is available to accelerate it forward…it may not provide enough speed and momentum to feed and return to battery if all isn’t just so with the feeding phase. The same can be said of the shock buffer, which dampens rebound.

In 1949, Colt introduced the Commander Model. It appeared to be no more than a Government Model with a short slide and barrel…but there are other subtle differences that aren’t apparent to the untrained eye. Most notably, the rails and impact abutment are machined .100 inch further rearward.

This regains a little of the lost slide travel, runup, and space available in the spring tunnel…which is very important because the available space was also reduced on the other end…when the spring is fully compressed by the slide. Too many coils, and the spring stacks solid before the slide is stopped by the impact abutment…which transfers the shock to the barrel bushing through the spring plug…which breaks things in short order…sometimes including the slide.

Colt had to do some slick engineering to get the Commanders to run. One of the things that they did was to wind the spring a little differently, which resulted in a slightly higher rate, allowing space in the tunnel with fewer coils. Although the springs were no different in structure or materials…the slightly wider space between coils allowed enough oomph without the danger going solid…aka “Coil Bind.”

Because of the reduced space with the slide in battery…it also resulted in a heavier preload of the slide than the GM had…which results in increased felt recoil.

Many believe that the Commander’s recoil is sharper because the less massive slide hits the impact abutment harder than the 5-inch slide…but it doesn’t. In fact, with the slightly heavier spring, it hits with less momentum and impact.

Why is that?

Because slide and bullet momentums are assumed to be equal.
The lower mass is moving at a higher speed…but the momentums are the same. Momentum being a function of Mass X Velocity. The increased felt recoil in a Commander is the result of lower weight and higher spring rate. The difference is much less noticeable in the steel-framed Combat Commander…but it’s still there due to the spring.

It’s also become widely accepted that the Commander and Combat Commander “standard” spring is 18 pounds, despite the fact that after testing many hundereds of new pistols over nearly 25 years, I have yet to find a Colt Commander with a spring that tests at 18 pounds. Nor have I been able to find a Colt Government Model spring that tests at 16.

A lot of this reasoning comes from the idea that if we don’t run a high-load spring in our guns, we’re destroying the frame every time we pull the trigger…but that just ain’t so. The recoil spring’s function is returning the gun to battery…not buffering shock. That it does do that is incidental.

A question that often comes up is:

“Can a GM spring become a Commander spring by cutting it shorter?”

The answer is…yes and no. It can be substituted, assuming that the Commander has a standard design recoil system…but because of the wind and the different rate…it won’t be exactly the same. Cutting a GM spring to the Commander’s standard 22.5 coils will result in a spring that’s shorter in free length…which cuts down on the preload in battery somewhat…which really isn’t all that important as long as the spring doesn’t go to free length before the slide is fully in battery and it has enough punch to feed the round and place the gun in battery.

The solution is to cut the spring to 24.5 coils, which leaves enough space in the tunnel without danger of spring bind in every Commander I’ve used it in. Because of the decreased preload space and the tighter compression at full slide travel…the resulting spring load at full travel is right around 16.5 pounds…or about a pound less than a Commander-specific 18 pound spring.

I’ve done this for years, in dozens of my own Commanders…steel or aluminum alloy frames…and in dozens tht belong to other people…without ill effect, and I haven’t bought a “Commander” spring in over 30 years.

One caveat. Be sure to check for coil bind before firing the gun. Specs can vary. Although I haven’t had it happen yet, that doesn’t mean that it can’t. As the wisdom goes: “I only know what I can measure.” A quick test is to install the spring and hand-cycle the slide briskly but not brutally, letting it hit the impact abutment. If you hear a sharp metallic noise…it’s probably good to go. If you hear and/or feel a dull thud or a crunch…it’s in coil bind. Trim a half coil and retest.

So…it won’t be the same spring…but it can be substituted.

This applies to Colt Commanders and faithful clones with 4.25 inch slides and standard recoil systems only.

I stated in my previous post on the topic that the purpose of the “recoil” spring is returning the slide to battery. This seems to cause a little confusion due to Bill Wilson’s advice to use different spring rates to “tune” the gun to the load…with the criteria being to use the heaviest spring that will allow the slide to lock consistently…and the yardstick being how far the brass flies on ejection.

I don’t want to pick on the old watchmaker unduly…but this very often leads to grossly overspringing the gun. There are too many factors involved in ejection distance than just the slide’s velocity when it hits the impact abutment.

Another cry that I hear is that, when firing hot-rod +P ammo, that a heavier spring is needed because of the pressure…or to protect the frame from damage…neither of which has any basis in reality. Like the ever-present shock buff…this seems to be marketing. People who are in the business of selling springs want to…well…sell springs.

To wit:

Convince the customer that he “needs” it…and then sell it to him.

By overspringing the gun, you really aren’t keeping it from breaking. You’re just changing what breaks. Remember that springs work in both directions. A stronger spring means slower rearward, and faster forward. Faster forward….faster than necessary…increases momentum and impact when the slide slams home. That places more impact stress on the lower lug feet…the slidestop crosspin…and the holes in the frame that the pin mounts in. While a good slidestop should endure…sometimes the holes and the lug feet don’t do so well. The impact abutments are designed to absorb impact. The other areas mentioned aren’t. Slip the slidestop pin through the barrel link and swing it to the in-battery position and take note of the tiny area of the lug feet that bear on the pin. That’s what is involved in actually stopping that 18-ounce slide and barrel assembly…driven by the spring.
I’ve seen oversprung Colt LW Commanders egg-shape those holes and crack the frames adjacent to the holes in the bottom with as little as 1500 rounds.

Overspringing also makes the pistol more grip sensitive. That is…more prone to limp-wrist failures to eject unless the gun is gripped firmly. A properly sprung pistol should function when cradled in the hand, barely supported with the thumb and index finger, with maybe the pinky lightly keeping the butt stable. If it won’t function when gripped in that manner, it’s a range queen…not a defensive sidearm.

Overspringing also increases felt recoil rather than softening it. I’ll get into that in Part 3.

Cheers, ladies and laddies.

11 thoughts on “1911 Recoil Spring Information”
  1. John truly is a wealth of knowledge of the 1911/Government Model. I learn something every time I read one of his articles. I truly appreciate this online gun magazine

  2. Nice to see John’s writings again, the man is a 1911 genius. Like Frank, I have learned tons from him. Thanks John!

  3. I’ve recently bought a para SF-45A compact I can chamber a round and fire it everything cycle’s just fine but if I have a live round left in the chamber and rack the slide back to eject the round the slide is like it doesn’t want to come back it will take everything you have to get it to can anyone help me out with this or recommend something

    1. What sort of ammo are you running? It sounds like you are having trouble clearing the pistol when ejecting the live round from the chamber. Out of spec ammunition, too large, or a small chamber can cause the unfired round to stick in the chamber.

  4. Very interesting article! So what springs would you recommend? I’m running a 16 lb recoil spring and a 22 lb mainspring in a 5 inch Kimber. I had tried to “tune” the pistol with an 18 lb recoil spring and 19 lb mainspring but was getting FTF. It’s running good now, but would you recommend and lower pound recoil spring?

  5. My BUL commander size 1911 has a GI style guide rod and a bull barrel. So the spring can not go out thru the barrel bushing due to the reverse plug end cap upon assemble. The spring seems to be all jammed up when assembling the gun. Am I hurting the recoil spring. Should I forget the GI style rod and reverse plug and go back to that dreaded two piece guide rod and take down tool? After I assemble the gun it racks well and all seems to be OK.
    Thank you

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