I have a pair of old mil spec 1911s. One has a lighter, cleaner trigger pull. If I wanted to keep the slide and frames together, what parts could I swap between the two that would give me the better trigger pull on the other gun? Trigger, hammer, mainspring? I can start by process of elimination, but figured I'd ask since there's a hundred combinations.

Just take your gun to somebody and have them do a trigger job. It's a simple process for a decent gunsmith and they can clean it up nice and set it where you want it within reason with the factory parts. Then you have two guns with a very nice trigger pull

They also might not be compatible. I don’t think you can swap a series 70 and series 80 trigger group. I could be wrong though.

They're both WW2 guns

It's really just trigger weight - not creep or takeup or anything like that

If it's trigger weight, you may can just take out the spring and bend it a little bit. It's not hard to do and if you don't want to do it to the original spring you could buy a new spring for a few bucks. But it's always reversible anyway

But having somebody who knows what they're doing can do that and stone the hammer and sear can sure make a lot of difference. If you ask around people you know, somebody made the stuff and can do it for you for basically free. I've got a friend who does mine for me. I've done the sear spring bending on a couple and it'll help, but stoning and such can make a real difference

Usually polishing and spring does the trick…. Recommend you take it to 1911 Academy in McKinney.

I'll second this.

Personally, I wouldn't mess with either. Just shoot them and enjoy what you have.

If you want to trick around with a 1911, buy a TISAS. They are well made and affordable.

This is bad advice. No reason to mess with Turkish crapper wear when a simple trigger job is the answer🤣🤣

Go to a professional and have a trigger job done. If the gunsmith is worth his salt then you can specific what weight trigger pull that you want. It is worth the $ paid.

There are some caveats to that. You can't go too light if you're trigger is physically heavy. That's the way it is in a 1911, not going to guarantee it's that way in every other gun. If you want to get down to that sub three pound range, you probably going to have to start using a lightweight trigger, especially on something like a 45 that has a fairly heavy recoil spring. That's why on a lot of things like STIs the trigger is made out of plastic. I don't know what the lightest weight solidly functional trigger you can do on a mil-spec trigger is. But I'm betting a clean crisp 4 lb trigger, or maybe a little less with mil-spec components will be pretty simple

You'll have to explain that one. Why would the trigger's mass itself matter?

Inertia.

With a heavy recoil spring like in a 45, the slide goes forward fast. When it hits the end of its travel, it drives the frame forward with it. If the trigger itself is heavy, like some of the steel ones, it wants to sit still. So when the slide hammers forward it effectively makes the trigger move backwards (because it doesn't move) and can cause Hammer follow if you don't have enough sping tension to keep the trigger from moving. You can get usually away with lighter trigger weight all else being equal on something like a 9 mm because the recoil spring is generally much lighter. But usually three and a half pounds or so is pretty doable even on a 45 with stock components

That's why you see lightweight aluminum or composite triggers for 1911s and 2011s

Interesting, I never considered that as an issue.

which spring in a 1911 affects trigger weight? Mainspring?

The main spring does a little bit, but I wouldn't mess with it as that can affect reliability of lighting off primers. The sear spraying will have the most effect on trigger pull

https://youtu.be/J_UAQ4SzQUI?si=8UdzDsj9CnXddoeL

Here's a video from Atlas on adjusting the sear spring

Thank you!