17# Mainspring too light??

[jlgone]

I purchased a Fusion mainspring housing with the mag well, and a Wolff 17# mainspring was included with it. I was not intending to change the spring, I just wanted to add a magwell.

My question is should I swap the mainspring form my factory housing into the new Fusion housing or use the new lighter Wolff spring. This is a range gun - never carry, and it is full size Kimber in 9mm if the caliber makes any difference. My understanding is Kimber 45's use a 21# mainspring but I don't know if the 9mm would have different one.

I'd appreciate hearing any advice. Thanks!

[grendelbane]

Lots of people get by using a 17# mainspring in their .45s, so I certainly wouldn't worry about using one in your 9mm. The trigger might be a touch sweeter. I use 23# in my .45, and a 25# in my 10mm, but that is just me.

So, I would say it is simply a matter of personal preference. Possibly, you might run across some hard primer 9mm, I have before. My Colt would always set it off, but a Browning Hi-Power I had at the time would not reliably fire it. There is not much of the old 9mm surplus floating around any more, so this may not be a consideration.

My advice is not to worry about it. If you change, and don't like it, you can always change back.

[mbuzha]

I went through a phase where I tried 17, 19, 21, 23# mainsprings just because I have a tendency to tinker and have trouble leaving things alone. I've since gone back to stock 23#. I can tell you I definitely had problems with a 17# in my Springfield when using cheap ammo (ie monarch at academy). many many light strikes. Never had any trouble with a 19# spring and above but keep in mind changing the mainspring changes everything...the entire gun works as a system. As they say, if it ain't broke...
Also, if your trigger breaks cleanly as it should using a lighter mainspring probably won't make a huge difference in trigger weight anyway. But if you are inclined to tinker (as I was) I would recommend AT LEAST a 19# from my personal experience anyway.

[wichaka]

It's easy to get safe 4.5lb glass smooth trigger pulls with 23lb main springs.
I personally don't use anything lighter than 20lbs...but most semi-custom makers like Wilson & Nighthawk use 18lbs regularly.

[log man]

The 17# is fine and used often , but don't expect good performance with a titanium firing pin as Springfield comes with.

LOG

[jlgone]

It's easy to get safe 4.5lb glass smooth trigger pulls with 23lb main springs.
I personally don't use anything lighter than 20lbs...but most semi-custom makers like Wilson & Nighthawk use 18lbs regularly.


Is there any benefit to reducing the mainspring to < 21# if I am keeping the factory trigger as-is. Does Wilson use such a light one for all theri 1911s or just competition?

The Kimber spec for trigger pull is ~4.5, and I am happy with it. It is cycling nicely so I wouldn't want to throw things out of balance. I haven't heard a good reason to use the lighter spring, so unless someone has a compelling reason to use a light spring, I'll just switch the springs when I install the housing and magwell.

Thanks for the advice!

[mbuzha]

Yeah, lighter mainspring will make the trigger a little lighter, but for me it wasn't a big enough difference to justify using an alternate spring weight...but for you it might be. Like Wichaka said, most of the big semi-custom guys (wilson, baer, brown) use lighter (less than 23#) mainsprings. I have heard most use 19# but this might not be necessarily true. Try a 23# and a 19# and see if there's enough of a difference to you to use the 19. Again, I personally wouldn't go lighter than 19# as I have had trouble with light strikes when using 17# springs.

[Frank]

Remember that the weight of the mainspring will affect rearward slide velocity, since the slide moving backwards under recoil must work against the mainspring to cock the hammer. In a full sive 1911, I personally prefer the standard set up of the 23# mainspring and 16# recoil spring.

DVC

[wichaka]

Really the best way to get a good smooth trigger pull, is to try the "Poor man's Trigger Job" first. Check out tech section for the instructions.

Have been doing something similar for years, and just didn't know it, til I saw it on here.

If one were to smooth all the contact surfaces on every part of the firing system, you would find in a lot of cases, where you would not need to purchase other parts.

I find without doing anything else to the firing system, but changing out the spring...there needs to be a drastic drop in spring weight to notice anything. A good 4-5+lbs.

And as Frank noted, it will change the way the gun recoils.

You change one thing, it affects many other things.

In just about every Wilson I have taken apart...and haven't had a new one apart in the last 3 years, they had 18lb main springs in them. Those guns had a 3.5lb trigger pull.

If you want a sweet feeling recoiling 1911...drop the recoil spring to 16lbs and add a square bottom firing pin stop. I run 14-15lb recoil springs in all my full size 1911's, and the recoil is even a bit better yet.

[1911goldcup]

I have a series 70 GCNM all original. Does anyone know what mainspring these came from the factory with ? Mine was mfg. 1981.