1911 Main spring in Gunsmithing Questions Forum

RSS
Email

0 Points

Forum Jump

1911 Main spring

Author	Comment
Trunkmnky	1911 Main spring	Lead	[-]
Posts: 137 Apr 30 12 7:30 PM Reply Quote More My Recent Posts	Tags : None Hello all, I was wondering is someone may answer a question about lighten mainsprings. I am currently shooting a STI Spartan V 9mm. I was wanting to lighten the trigger. I was thinking of changing the main spring to 17lb. I understand stock is normally 23lb. I have polished the Sear and hammer and still not quite satisfied with the trigger pull. So outside of bending the sear spring I was wondering if the lighter mainspring would be affective. One other part is will it affect the strike on the primer if say I am using a soft or hard primer. As all I want positive ignition. Jeff H. SO - A47095

MTSCMike		#1	[-]
Posts: 62 May 1 12 7:41 AM Reply Quote More My Recent Posts	I use the 19# mainspring in all my 1911/2011 pistols and have no ignition issues. My trigger pulls are between 2 and 3 lbs Mike Maples IDPA # A00640 SO/SO Instructor
jblackfish		#2	[-]
Posts: 341 May 1 12 7:48 AM Reply Quote More My Recent Posts	Jeff, Have you measured the weight of your trigger pull? I'd be curious to know how light you want to make it and advise you that IMO less than 3 1/2 lbs is not advisable. Depending on your experience level - shade-tree gunsmiths excluded - if you're wanting to lighten the trigger pull weight, you'd be better off to make a slight adjustment to the sear spring and leave the 23# mainspring unaltered. You can lighten the trigger pull by bending the middle leaf of the sear spring back a little (bend forward to increase) but be aware that the middle leaf also operates the disconnector so carefully function check your pistol after adjusting anything...and more carefully test fire it after adjustments!!!!! Going to a lighter mainspring would lighten the trigger somewhat but it would also lighten the hammer strike which, as you indicated, might have an effect on performance depending on the primers you're using. I'm sure you realize that the full-size production 1911 was designed for a 16# recoil spring and 23# mainspring and, although it'll work with changes to the springs, I'd be very careful (and perhaps hesitant) to make changes to that. When you make a change to one item you usually impact several other areas so tread lightly and good luck. John - A38716 What goes around comes around.
RickL		#3	[-]
Posts: 742 May 1 12 9:05 AM Reply Quote More My Recent Posts	One thing to remember, the mainspring and recoil spring impact each other. Tinker with one to solve a perceived issue and you may cause a new issue. People working to get their balance of hand loads and minimum felt recoil go through many malfunctions to find what they like. And the 9's are even more delicate than the 45's. What John cautions above is mostly true, only it is the left leaf of the sear spring that makes contact with the sear. You can lighten or stregnthen trigger pull. Just remember this: When you play with these, you are also introducing a risk of doubling or worse so you have to function test the pistol after playing around. Make sure there is no hammer follow when you drop the slide and load your first mag with one or two rounds to test your adjustments. Gradually increase the rounds to be sure you dont become the center attraction at a floor show. Rick A27521
jblackfish		#4	[-]
Posts: 341 May 1 12 10:05 AM Reply Quote More My Recent Posts	Rick, It's correct that the left leaf of the sear spring contacts the sear but it's the middle leaf, the one that contacts the disconnector, that affects the trigger pull increase or decrease. Secondly, changing the mainspring will have a small effect on the trigger pull but more on hammer cocking and hammer strike. John - A38716 What goes around comes around.
Trunkmnky		#5	[-]
Posts: 137 May 1 12 6:04 PM Reply Quote More My Recent Posts	Thanks guys, I have been around the auto 45's when people were lightening the springs. I was trying to avoid that. :-) As it is definitely not a good thing and that person was the floor show for sure. I have 3 kimbers ( all in 45 ) and all are set to approx 4lbs. I would have to guess as I don't have access to a trigger pull gauge that it is ringing in around 6lbs. As is I stated I don't want an issue with ignition with different primers. The load I am using is good and rings in at 1098 on chrono. 4.4grs win-231 and 124gr rn. I have a few sear springs. So maybe I will try to adjust one. Just not found of the idea. Never seem to get it right normally to light. ( Thank god no doubles yet on any 1911 ) Thanks for all the info and quick responses. I really appreciate the assistance. Jeff H. SO - A47095
jblackfish		#6	[-]
Posts: 341 May 2 12 8:01 AM Reply Quote More My Recent Posts	Nevermind. I just noticed that we're talking about a 9mm - I had .45 in my mind. John - A38716 What goes around comes around. Last Edited By: jblackfish May 2 12 9:29 AM. Edited 2 times.
RickL		#7	[-]
Posts: 742 May 2 12 1:43 PM Reply Quote More My Recent Posts	If you have a couple springs, keep one on hand so you can compare the geometry in case you bend too much one way or the other. It really just takes a little to make a change. But you should also have a guage on hand to measure the amount so you are not guessing. Tweek the left finger back very gently. Just enough to give you a perceived bend. Make sure the surface that is making contact with the sear does not have a sharp edge to it. Polish it some. I do the same with the cooresponding surface on the sear. Put a 2000 grit emory cloth on a piece of wood. You can find them at auto stores for wet sanding. Makes surfaces appear to be like glass. Do the same with the back side of the trigger bow since, that is what pulls the sear back. You will see where the contact points are. Rick A27521
RickL		#8	[-]
Posts: 742 May 2 12 2:05 PM Reply Quote More My Recent Posts	Here you go, I went through a library of pics. This shows the three fingers on the sear spring. You can see the contact with the sear on the left. The middle finger contacing the disconnecter gives upward pressure to re-engage when the slide is out of battery. A very important task regarding safety. Rick A27521
Trunkmnky		#9	[-]
Posts: 137 May 2 12 8:04 PM Reply Quote More My Recent Posts	Thanks for the great posts guys. I have it at 4lbs not and man does it feel nice. :-) Function tested it today with about 150 rounds and worked flawless. Though I still have one question. I bent the middle spring to accomplish this. Did I bend the wrong spring. If so can anyone explain why this lightened the trigger. Jeff H. SO - A47095
Gregg Kratochvil		#10	[-]
Posts: 986 May 2 12 9:12 PM Reply Quote More My Recent Posts	Trunkmnky wrote: If so can anyone explain why this lightened the trigger. The total trigger pull is made up of many things that each contribute to the overall pull. The center leaf that you bent not only pushes up on the disconnector but also pushes forward on the trigger bow so that is why it got a little lighter. Working on everything to have a proper balance would be preferred. Working on half of the parts usually ends up with a half @$$ trigger job. Understanding how everything works together is important. Jack Weigand wrote a very good article for Brownells on trigger jobs that is very much worth reading and understanding. 2 1/2 lb Trigger by Jack Weigand

RickL		#11	[-]
Posts: 742 May 3 12 9:31 AM Reply Quote More My Recent Posts	Jefff, you are fine. As Gregg mentioned, the pressure on the disconnector is also the pressure for the trigger reset and pretravel. When you relax them in concert with each other, you can raise or lower a couple pounds without polishing or stoning anything. With the caveats mentioned. The document posted is a good primer on triggers and a way to do trigger jobs. Just remember, Brownells is selling that fixture which is featured in the article. WHile it is a good fixture, it does a lot more than 1911 triggers and is priced accordingly. It sounds like you are happy with the adjustment of the sear spring. You probably saved yourself other grief ( or bench work) by leaving the mainspring alone for now. Rick A27521
Gregg Kratochvil		#12	[-]
Posts: 986 May 3 12 10:05 PM Reply Quote More My Recent Posts	Jeff To answer your original question. I have run well over 100K in 1911's with a 17 lb ISMI mainspring and never had a light strike. I don't know how it would work in something like a Springfield with a Ti firing pin but with a standard steel firing pin I had no problems. Keep in mind that changing the mainspring not only changes the hammer spring rate but it will also change the way the gun recoils as the mainspring is one of the things the slide must work against to cycle the pistol. So not only will the mainspring change the hammer fall and trigger pull but also the way the gun feels while cycling.
Trunkmnky		#13	[-]
Posts: 137 May 4 12 4:18 PM Reply Quote More My Recent Posts	Greg, So with the above being said Changing the main spring could possibly work against you in the hammer fall would be slower ( not that I am fast enough to notice ) However, cycling could be faster as less tension to push against. So one could possible even out the other. Thank for all the info gents. Keep it coming. Sounds like you al have been were I am at and passed. Nothing can be experience. :-) other then a lot of headaches and time at the bench. Jeff H. SO - A47095
Gregg Kratochvil		#14	[-]
Posts: 986 May 4 12 6:28 PM Reply Quote More My Recent Posts	Jeff Yes, on paper you could say that the hammer fall may be slower. I don't think that anyone would be able to notice but technically if the lock time was slower you could get it back by installing a lighter skeletonized hammer that would have a faster lock time. In the run and gun games I don't see where anyone could possibly notice. You will often hear someone say that they were waiting on their gun because the gun runs slow. Keep in mind that the average machine pistol runs about 1000 rounds per minute or .06 splits. To have to wait on the gun you would have to be able to pull the trigger faster than .06 splits. I don't know anyone capable of shooting less than .06 splits. If you have to wait on your gun it either has something seriously wrong with it or you are the fastest individual on the face of the earth. It is interesting the number of things that can change the way a 1911 feels under recoil. There are a lot of different combinations to experiment with. Small things like the amount of radius at the bottom of the firing pin stop can change the way it runs. I have killed my share of parts learning and playing around with different combinations with the 1911 but have learned a lot and enjoyed all of it. I think many of us have the "I must tinker" illness, just be safe while doing it.
Cody Ray		#15	[-]
Posts: 125 May 10 12 9:22 AM Reply Quote More My Recent Posts	ISMI 19# main spring, short radius firing pin stop, Ti firing pin with heavy firing pin spring, ISMI 15# recoil spring in all .45 1911s. Greg tinkers more than me. Cody "An APPEASER is one who feeds the crocodile hoping it will eat him last" Winston Churchill Cody Ray A03452 Last Edited By: Cody Ray May 10 12 9:25 AM. Edited 1 times.
Gregg Kratochvil		#16	[-]
Posts: 986 May 10 12 10:24 AM Reply Quote More My Recent Posts	Cody Ray wrote: ISMI 19# main spring, short radius firing pin stop, Ti firing pin with heavy firing pin spring, ISMI 15# recoil spring in all .45 1911s. Greg tinkers more than me. Cody Yes I like to tinker but you are running one of the best combinations I have tinkered with plus I really like the ISMI springs. Got to love a sweet running 1911.
Trunkmnky		#17	[-]
Posts: 137 May 10 12 1:55 PM Reply Quote More My Recent Posts	Hahaha, I think Greg said it best a few posts back. "I think many of us have the "I must tinker" illness, just be safe while doing it." Still tinkering with mine to get some better accuracy. Tighter bushing helped a some. Not sure if I want to get a match barrel. May sell it and just get something better and start again with a few more upgrades. Maybe go with a Kimber or Springfield. Sell the STI Spartan V. Unless..... drop some more accuracy ideas now. Slugged the barrel and it is .355 I have tried .357 but no better actually worse. Keep me tinkering. :-) Jeff H. SO - A47095
RickB		#18	[-]
Posts: 325 Aug 28 12 6:39 PM Reply Quote More My Recent Posts	STI's higher-end guns come with 15# mains; is the Spartan different? A buddy has had considerable trouble trying to ignite Russian primers with his STI Edge.
RickL		#19	[-]
Posts: 742 Aug 28 12 7:43 PM Reply Quote More My Recent Posts	Hammer drop is a function of the mainspring. But the Russians might be trying to seek revenge on us 'mericans. Rick A27521

<< Previous Topic Next Topic >>

Yuku free message boards

1911 Main spring

1911 Main spring