Need advice on replacing 1911 sear spring


June 30, 2013, 08:48 PM
Hello - I have a Springfield Armory 9mm 1911 that I'd like to lighten the trigger pull on. The trigger is crisp, but just a bit too heavy for my taste.
I bought a Cylinder and Slide "Light Pull" sear spring that I'd like to put in. Based on customer reviews of the part on Midway, it appears to be a drop-in. From what I have been able to gather, I only have to remove the mainspring housing and then the sear spring will come out. (Let me know if otherwise.)
My question is whether there are any particular precautions I need to take, or whether this is pretty much a "remove and replace" operation. I don't plan to do any spring bending if possible.
Also, although I have searched Youtube, any links to good instructional videos on how to do this will be appreciated.

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June 30, 2013, 09:52 PM
Yes remove MSH tilt your grip safety up and replace. Just remember that your grip safety must be depressed in order to put the MSH back on.

June 30, 2013, 10:09 PM
Military manuals describe this process pretty well. I suggest finding them.


June 30, 2013, 10:10 PM
After the install, check the trigger pull weight. Lighter than 4lbs may be a problem. Really depends on the hammer/sear engagement.

July 1, 2013, 09:45 AM
Pay attention to what I call the "fingertip" of the spring and make sure that it rests against the bottom of the sear/disconnector.

July 1, 2013, 11:23 AM
Its easy to do, but save your old sear spring just in case. Make sure after you install the new sear spring that the gun passes all safety checks.

I had a Les Baer that was safe at 1.75lbs but that was way too light for me. I put a Wolff spring in and took it right up to 3.5.

July 1, 2013, 12:28 PM
Stop the press! If your Springfield has the ILS internals, there are further precautions. An ILS (Internal Lock System) has no main spring cap retainer pin. You must therefore: cock the hammer and slip a pin (or small drill bit) into the hole to retain your MSH guts then decock the hammer. If not, tapping the MSH retainer pin out will allow your housing and its contents to jettison across the room.

Now would be an excellent time to confirm what you have and how to detail strip your 1911.

July 1, 2013, 01:30 PM
I don't plan to do any spring bending if possible.That was your first mistake.

You could have easily adjusted the stock spring in the gun in about 5 minutes to arrive at the same result.


July 1, 2013, 01:43 PM
If your Springfield has the ILS internals
The main spring has nothing to do with the sear spring. The sear spring is the 3 fingered leaf spring the mainspring housing holds in.

Buy a quality sear spring (leaf) install it and test your functions and trigger pull. You are good to go.

July 1, 2013, 02:10 PM
It does if he intends to take the mainspring housing out to replace the sear spring.

As Skylerbone noted, the Springfield ILS mainspring housing doesn't have a pin to make the Mainspring housing and it's inner parts a captured assembly.

If he punches out the mainspring housing pin without pinning the mainspring first, the internal lock system will be flying everywhere.


Jolly Rogers
July 2, 2013, 05:47 AM
Yep. Many threads about "Springfield forgot to install a pin in my MSH..." or " I lost a part of my gun" or the like.:cuss:

July 2, 2013, 06:42 AM
Yes remove MSH tilt your grip safety up and replace.

That's a good way to NOT get your sear spring in correctly. The chances of getting the left leg on top of the sear are iffy at best.

Just remove the thumb and grip safety and make sure that the left leg is on top of the sear foot. Slip the MSH partway in to capture the sear spring...and proceed.

After it's back together, if you find that the hammer won't cock...the left leg of the spring is under the sear. Take it back apart and start over.

July 4, 2013, 12:58 AM
you are getting good advice but no one has mentionrd the mainspring. the factory mainspring runs about 28 lbs.--ouch. why not replace it with a 19.5 lb. spring since you want a lighter trigger and you already have the gun apart. i took my ILS out and used a stock mainspring cap with the 19.5 lb. spring and the Nowlin sear spring, arguably the best one out there. whatever you do keep it safe and have fun personalizing your gun.:evil:

July 4, 2013, 07:39 PM
Use a Colt sear spring.

Sent from my ADR6425LVW using Tapatalk 2

July 5, 2013, 08:29 AM
Thanks all, lots of good info here but I need some clarification on a couple things. I've done further research and looked at some videos, and am "getting there" but am not quite there yet.

1) Regarding the ILS on my gun. First, thanks a million for pointing that out. I think several of you are saying my MSH doesn't have a pin to retain the mainspring, like other 1911s. I do see the hole you are talking about near the ILS, and of course there is no pin there as you note. I realize the pin normally holds the mainspring cap in. I am guessing the ILS does the job of the pin in retaining the mainspring cap. See this link:

So ... you are saying to: a) Have the ILS in "unlocked" position, b) cock the hammer which will compress the spring, c) insert a pin, drill bit, nail, etc. into the hole to act as a substitute pin, d) then decock the hammer to uncompress the spring, and the drill bit acts as the retainer pin, e) then remove the MSH as normal. (And reverse to re-install.)

Makes sense, so tell me if I have it right.

As an experiment, I did take a 5/64" drill bit and cocked the hammer (on my unassembled gun) and I did notice that the drill bit dropped down further into the hole after I cocked the hammer. Then I uncocked the hammer and the drill bit was "captured" in the hole (it doesn't fall out when shaken) and the hammer came to about half-cock position and was a bit floppy/loose. I assume this is normal and what you are all talking about.

Here's a photo from Midway which seems to show what you are all talking about:

2) I think I am getting some differing advice here on what I need to remove -- other than the MSH -- to replace the sear spring. Will I also need to remove either the thumb or grip safety, or can I simply slip out the current sear spring and slide the new sear spring in? And when sliding the sear spring in, do I need to push down the grip safety somewhat or fiddle with anything else?

Thanks again.

July 5, 2013, 08:37 AM
You pretty much have to remove the thumb safety and grip safety to make sure that the sear spring is installed properly.


July 5, 2013, 09:24 AM
Thanks. This is an ambidexterous thumb safety, so you know what my next question is: How to remove it. It seems you simply pull the right side off first, then the left side as normal. Correct?

July 5, 2013, 11:09 AM
Remove right stock (grip panel), cock hammer, insert pin in MSH, slide thumb safety to mid-position, remove TS being careful not to loose plunger spring and detents (these will fly rearward when removing thumb safety: now is a good time to add a kink to the spring if none is present), decock hammer, tap out MSH retainer pin, slide off MSH, remove grip safety, remove sear spring.

Replace sear spring with left leaf "hook" over sear leg, middle leaf on disconnector bevel, bottom of spring retained in slot. Slide MSH partially into place to hold sear spring, slip GS in to place, slide MSH fully up being careful to align the hammer strut with the MSH cap and the GS groove, replace MSH retainer pin, cock hammer, replace TS, replace right stock.

If you're going this far, may as well clean up the extractor and channel and the sear and disco as well then lightly oil them. Again, watch for flying parts under spring pressure such as the firing pin which could also do with cleaning.

July 5, 2013, 12:02 PM
I've never had to remove the thumb or grip safety when replacing sear springs. Just pay attention to the tips of the fingers. I use a dental pick to make movements or change the positioning of parts. Takes me about 5 minutes to do. But I've never had a Springer with the ILS, so maybe that makes it more difficult.

July 14, 2013, 01:36 PM
Thought I would circle back with everyone. This turned out to be an easy job and went exactly as Olympus notes above. I simply removed the MSH (after putting a pin in the hole to prevent the mainspring from escaping), jiggled out the original sear spring and jiggled in the new Cylinder and Slide sear spring. No need to remove the grip safety or frame safety, and I didn't even remove the slide. I did no bending to the spring, and didn't want to. Looking at some Youtube videos helped a lot.
Dry-firing, the trigger weight has dropped from ~ 5 1/2 lbs. to ~ 4 lbs, which is fine with me. I haven't live-fired it yet, but it passed all the dry-fire safety and function tests. Took about 15 minutes.
Best $8 I ever spent.
Thanks to all for your advice.

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