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Discussion Starter #21 (Edited)
I'm a recent mechanical engineering grad. I did spring design for car door handles (torsion springs specifically) during a summer internship, so I learned more about springs than most people would care to :p

You won't be able to much of anything about the hammer spring. Square wire springs produce much more force than round wire springs, and are less economical to produce.
Did you say (won't be able)....:eek::p I'd hate to have to grab the low E flat wound guitar string off my Strat and make one.

OK, just what we need...a spring expert. I understand that flat/square wire is the best for torsion springs. Where I am going with this hammer spring is in the trigger job thread. My concern is that the existing hammer spring places unequal pressure on the hammer since the leverage is off center. What do you think about that idea? Then take the double torsion spring that is fitted to the trigger/trigger bar and imagine a hammer spring of that shape but of the proper length, coil diameter, width, etc. I have no idea how you measure the torque it takes to wind one leg of the P22 hammer spring from free rest to the position the cocked hammer moves it. I do know that hooking a Lyman trigger pull gauge to the hammer requires 8 lbs of pull to cock the hammer with a new spring. I have purposely overwound these springs to a new set but didn't do this scientifically....like mearsure just how much rotation I did to acheive a new at rest angle. I just did it by feel. At 7 lbs everything is fine. At 6.5 lbs.....light firing pin strikes begin to occur.



Off center pressure.....real or not with the P22 torsion sprin? I'm concerned about this regarding hammer and sear work. Below is a Walther manufactured double torsion spring in a P38. It appears to be of round wire. If it was good enough for a P38, it would be more than good for a P22. So can something like this be fabricated for the hammer spring so the forward pressure is even on the hammer and frame? Glad to have you join in this discussion. I'm a landscape architect and have no engineering background at all. I do know what passivation is thanks to MG Mike using that big word. Had to look it up.... M1911
 

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Discussion Starter #22
Sosumi, I also think you should get out your calipers, CAD thing and design a shorter but fully funtional recoil spring both a constant rate one and one that gets stiffer at the base. One for Mini Mag energy and another spring for lighter subsonic and target loads. Then you should design a double hammer spring that will work inside the narrow space of the P22 hammer. We took a vote and you get the job. Thanking you in advance. :) Oh yeah....there have been some issues over the years with the trigger bar spring becoming overwound. Could you look at that too. What would really be great is if you could design a hammer spring with built in mechanical advantage for the cocked hammer. The current problem is that the torsion spring presses the hammer face up against the bottom of the breech block with 8 lbs of drag as the slide moves over it. And....hate to bring it up....but the little v spring that holds the stop arm down is really easy to lose. I'm thinking a magnetic one that sticks to zinc would solve that issue. M1911
 

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Ok, quite a few things to address here. I'll cover the big picture things first.

First, I believe the off-center hammer torsion spring thing to be a non-issue. The hammer is supported equally from both sides thanks to the dowel pin; unless your hammer and pin have noticeable play, the amount of binding produced by the spring should be negligible.

Second, measuring the torque on a torsion spring is not so simple. It depends where along the leg the force is applied. Also when a torsion spring winds, the number of coils increase slightly, and the lever arm changes as well. There is no such thing as a constant force torsion spring. (Not to be confused with a constant force spring like in a lawnmower pull start). I'm by no means a spring expert :eek:

Haha, well I do use SolidWorks at work... Like torsion springs, compression springs do not produce a constant force. The closest thing would be a multistage spring. I want to say that some Glocks use this concept???

In my opinion the biggest problem with the P22 is that the hammer rides on the breech block. Perhaps the best way to go about coming up with a new recoil spring is to determine the minimum force required to chamber a round? i.e. strong enough to strip a round and push the extractor over the rim and hold the slide forward.

If you can find something with about the right diameter this would be a cheap way to experiment.
McMaster-Carr

FYI the P22's braided wire compression spring seems quite unique to me (again not a spring expert though). It was designed that way for a reason. Probably to get a higher force in a shorter package.

Lastly, zinc is not magnetic :p Also I no longer have access to the spring design software...
 

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First, I believe the off-center hammer torsion spring thing to be a non-issue. The hammer is supported equally from both sides thanks to the dowel pin; unless your hammer and pin have noticeable play, the amount of binding produced by the spring should be negligible.
Looking at mine the hammer and pin have noticeable play (pictured)



 

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Man... 10,000 CCI .... what you thinking...

Dang 1911,

You must think I'm the federal government....10,000 rounds !! :) At any rate, what you and Sosumi have going on , springs, tension, lbs. of torque, spring constants, etc. ... man, at the very least, you have MORE than taken on my challenge.

It seems that your experimentation with the removal of spring coils, and now with the assistance of one who has studied springs, and their properties, such as square springs as opposed to round coils, springs that might consist of coils ie, the recoil-compression spring on the P22 (which I almost shot across the yard today, but luckily found this afternoon).

Anyway 1911, although you posted this thread as my challenge, I am glad you have made some progress toward making this little pistol more adaptable to firing OTHER ammo than what is normally associated with it, such as the CCI mini mags or the RGBs. I really found your experimental findings with this gun extremely interesting. You certainly know your way around the P22, and maybe even through this "challenge" you learned some things about adapting it to fire other ammo, as stated previously.

You know my friend, after your findings with this challenge, perhaps someone should add a chapter II to the P22 bible. Without a doubt, what you have discovered during the course of your work on this project will be helpful to some P22 users, including myself, now and in the future...since once I go out and purchase 10,000 rounds of CCI, others will have to settle for "other" ammo. They will need your spring-modifications in order to shoot whatever kind of ammo is available.

Now, do you think you could put your findings in plain English for those of us who might want to make clips to our springs, and apply some of your other findings in order to fire what I will term "generic ammo", which will include those Remington Subsonics you showed in your pic, (which I have 3 boxes of), as well as any other loads that usually FTL, FTF, or FTE.

Without a doubt, your work helps to educate us all. If none others before have before me, I really thank you for that work and especially for you freely sharing it with us. BTW, I really don't live too far away from Indian Springs, as the ride from the Montgomery area is mostly Interstate ... so when I show up at your door, expect me to have my P22, and some ammo, but not 10,000 rounds of CCI ( but we can ALL dream, can't we) ... Take care my friend, and keep posting.
 

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Discussion Starter #27
Summary huh... The first thing I would suggest is to get some of the actual ammo you are wanting to test before doing a lot of mods. That is easier said than done these days though. The purpose of this thread was to make the P22 cycle Remington SubSonic ammo. Not having any ammo led me to remove probably too many coils. Had I had some actual ammo to test I think it woudn't be necessary to remove as many coils.

The first thing I would do is take a clean pistol and try the SubSonics. If the spent case won't extract or if it extracts but the slide doesn't move far enough rearward to pick up the next round....then the ammo isn't powerful enough and the spring can be shortened. I removed full coils, less than this amount can be removed. Then I would remove coils until the pistol cycled properly.

What I think is that we need two springs. One for regular high velocity ammo and one for weaker, target and subsonic rounds. Here is why and what I found shooting this weekend. The weaker recoil spring allows the slide to be blown fully rearward....this works fine as long as the pistol is pretty clean and still lubed. What I found happening after a couple of hundred rounds of Federal 510, not plated, is that the weaker spring would not always close the slide fully. A round would be stripped but the slide didn't chamber it nor could you fire it. Clean the chamber just a bit and it would return to 100% for four or five mags. The stock spring has enough energy to close the slide but is too strong for weaker ammo. Snappy ammo and the stock spring make for the most reliable pistol.

This is why I would recommend testing with the ammo of choice. I had no issues cycling Rem subsonics and believe I could have left one or perhaps two of the coils on the spring. This would go a long way toward alleviating the spring being too weak to close a dirty slide. The good news is I fired several hundred regular hv rounds and the slide still didn't break. This is on an old P22.

Then, I measured out 82' and tried my hand at Crete shooting. The distance isn't as far as I was thinking but hitting the 10 ring is sure difficult. I did that shooting with the Q model. I hven't cleaned it and will check the trigger pull before cleaning to see how it is holding up. That short barrel sure isn't a rifle but a man size target is very easy to hit. I didn't work at it too hard, two days of bush hogging, mowing, cleaning, hauling stuff off and it was hot and humid. Got back to B'ham at 1:30 AM.....ahhhhh, ready for a concrete pour this morning. We got that in.

Two springs would solve the issue for those that want to shoot subsonics. I'm still sticking with RGBs. I'll put up a picture of my target as soon as I drag it out of the I Phone. :) M1911
 

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Discussion Starter #28
Crete, therein lies the ultimate problem with a zinc frame. It might be the angle but there appears to be a larger gap between the left side of the sear and the hammer hook. I suppose some very thin shims could be added to each side of the hammer to tighten it back up in the frame. I'm assuming the hammer's pivot pin and hammer hole haven't worn. If the frame is worn...I don't know what you do about that. M1911
 

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Just a quick question 1911. You think it would be feasible to simply find a different spring....say one that has the same dimensions as the stock spring, such as matching diameter, perhaps even the same length, but not as strong?

What I am getting at here is that some supply places such as Grainger or some other similar supply place, sells springs. Suppose one took the p22 spring in, or at least the dimensions, and got a somewhat weaker spring .... Like a single coil ( single wire ) wound spring, as opposed to the helical-type coils used in the stock p22 spring.

Do you think something like this idea would serve the same function as cutting coils off the stock spring, like you did? I mean, removing coils like you did seems to only give a weaker spring. Or perhaps you need the initial blowback "energy" to begin the process of snapping the slide rearward as opposed to it having to begin its "initial" rearward snap without any kind of forward pressure that a spring would exert.

With the stock spring shortened from the removal of coils, the slide begins its rearward snap without anything pushing or holding it in the forward position. I wonder if it needs this "free" rearward snap before contacting the shortened recoil spring in order to complete the cycle, or would the be enough blowback pressure for it to complete the cycle with a weaker, but full-length spring in its place ..... Hmmmmmm !! There's some food for thought.

Can't wait to hear from you, or "Mr. Spring man" ie. Sosumi.

All the best.
>>Chemrat22
Stupidity is the most abundant element in the Universe. ... Frank Zappa
 

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Discussion Starter #30
Yes, I think any combination of springs might work. The spring needs to be long enough and strong enough for the intended purposes. Walther has installed a spring that they feel best serves the pistols for world ammo varieties. Wheter or not something can be found on line or at a spring store isn't known to me. The Ruger SR22 spring is much shorter but operates as very similar slide. The Ruger probably won't cycle target or subsonic rounds reliably either. Other than trial and error a spring manufacturing co might be able to assess the P22 spring and supply springs in various weights and lengths. Outside and inside dimensions will need to remain similar. Walther also uses a wound strand spring and I don't know what the advantages are with that.

It will be important for the spring to exert enough force to reliably close the slide. Wolff.......where are you? M1911
 

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Could using a stock catalog spring be a feasible replacement? The answer is yes, if you can find some with appropriate ID and ODs. I posted a link to McMaster compression springs earlier. (Grainger is fine too, probably harder to find your size though).

The guidelines are as follows:

For springs with the same free length and wire diameter, more coils=weaker, less coils=stronger

For springs with the same free length and number of coils: smaller wire diameter=weaker, larger wire diameter=stronger

I don't know for sure, but the twisted wire spring is probably to increase the force to size ratio of the spring. It may also improve durability.

M1911, Do you know how much the original spring compresses? For this spring length is there room to add more coils? We want to avoid fully compressing the spring (bottoming out so the coils touch one another).

It may help to refer to the following common terminology (which I just made up):

Free position - condition of the spring when removed from the gun, this is the free length, the spring exerts no force
Home position - condition of the spring when the gun is ready to fire, spring slightly compressed, spring exerts light to moderate force
Compressed position - condition of the spring when the slide is locked rearward, spring greatly compressed, spring exerts highest force here
 

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Discussion Starter #32
The O ring thread goes into full compression of the spring and pictures of slide position. In normal operation there is room for a couple of additional coils as I recall. The issue is when the slide is removed. The slide has to be moved far enough rearward for the slide to clear the frame rails. There is room for an O ring which still allows the slide to move rearward enough for ejection and the slide stop to catch. Pulling the take down lever down allows more room to pull the slide rearward but you are approaching a solid spring. This is easy to test. Somewhere I have the dimensions of the fully compressed spring.

I have also stretched a stock recoil spring to the point that mini mags and RGBs won't cycle the slide. M1911
 

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Discussion Starter #33
I'm thinking we need a ballistic chart out of the P22 barrel of a wide variety of ammo. Energy is based on velocity and bullet mass. Most of what I'm seeing posted on various ammo might be correct for a 20" or 24" barrel but pistols don't achieve that velocity. So the energy of the round is less. I'm not sure what is going on here but on paper some of these rounds have the same velocity and energy. Out of a 3.4" barrel they obviously don't. Does it have something to do with the speed the powder burns?

If we developed an accurate chart, like By The Inch, did for a few rounds fired through the P22 we could calculate accurate energy of rounds in the P22 and get a clearer picture of where the breaking point is for when rounds are not quite powerful enough for the stock P22. I think the recoil spring could be manufactured with a bit less strength which would allow weaker rounds to cycle the slide but it is a two part process especially with the breech block dragging over the hammer. There has to be enough spring energy to close the slide. Four coils clipped off the stock spring will allow the pistol to cycle weak subsonic ammo but eliminates the pistol being able to reliably close the slide when the pistol get dirty from my tests,......which are very limited I'll admit. More new stuff and I will refine it. M1911
 

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Hey 1911. I have been watching and keeping up with your work and data on reliably firing sub-sonic ammo and find it all very interesting. What do you think about some kind of "double-spring" setup, much like those use in the Kel-Tec pf9, for instance (I own one of these, and man is it sweet) ? Anyway, and I am no spring man, nor am I anywhere near as knowledeable about the inner workings of handguns as you, but perhaps a shorter spring inside a longer one would provide enough "spring energy" to send the slide back to accomplish full battery....heck I think I might be gasping for air as I am likely showing my true ignorance; but I guess if I throw it out, someone with the knowledge will either take it and build upon it, or else completly disregard it. Errrrr, do I still gotta come up with 10,000 rounds of CCI ?

>>Chemrat22<<
 

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Discussion Starter #35
Fork em over.....I'm planning on being at the Wetumpka blues festival this weekend. Friend will be playing in the Dixie land band. He is the banjo player but can play anything and play it well. Meet you there, bring my wheelbarrow full of ammo. I don't know anything about springs either. I think a number of set ups would work. Whatever, the spring must be weak enough to let a .22 round to blow the slide all the way back. It must be balanced with stiff enough to close the slide and it must err on the stiff side due to wear and tear. I know that my P22s hammer back pretty hard with the breech block mod and moly. The slide still has to cock the hammer though and that noticeably slows the slide action that I once saw in a slo mo video someone posted at RFC.

I need one of those million frames per second cameras so I could look at the blowing out case on the rim. How they hit the ejector, what the extractor is doing, what the slide is doing. Bet Walther doesn't even have one. I know where one is, digital, I might ask to borrow time on it. The problem will be the shooting part. I'm not sure this testing lab will buy that part. They let me use some of there stuff....Rockwell hardness tester, microscopes.....I wasn't allowed to use the scanning electron...All I saw was an on off switch.

I think a lighter hammer spring would work....I should say....I know one will work. They could drop from 8 lb to 7 lb. Would help with pressure on the slide too and frame rails. Some pistols come with two springs. Regular HV and a target ammo spring. I still think one or two coils could be removed to weaken the spring and it will still have plenty of length and strength to close the slide...particularly if you don't run an extremely dirty pistol. Mine with 4 cut coils was a little weak on closing when playing with it dirty but it cycled fine for the 300 or so rounds I fired. I didn't clean it and they were the Federal somethings after I tested the subsonic ammo.

The subsonic ran fine. A little more than powerful enough. When I was cutting coils I didn't have any ammo except some old target stuff that apparently was really weak. Much more so the Rem Subsonics. And, the Wolf stuff was almost cycling. I bet newer Wolf match target would work. I will get more springs and find out. Documenting some of this stuff is what is important for future work. Documenting the pull required to move the slide to a certain point is necessary to compare spring strengths for future work. I could also measure the compressed length and then make a device to very accurately measure the weight it takes to compress a spring to that length. Oh well, enough rambling. Give me back my boolitz. M1911
 

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Discussion Starter #36
There are two groups that could sort the springs in short order.. Walther and Wolff Gun Springs. I've contacted Wolff before and they weren't interested. I'm not sure spring are hard to make...oh sure if you are making 10 million of them you need a fancy spring making machine. There are some good videos of springs being made. Pretty interesting. Springs are essentially bent metal and there are thousands of shapes. Round wire, square wire, flat wire, etc. Perhpas there is someone at Wolff that would lend a little off the record advice. McMaster didn't have any that were even close from what I could see.

M1911
 

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Discussion Starter #38 (Edited)
Compression Spring Calculator

http://www.acxesspring.com/spring-measurements-specifications.html

http://www.acxesspring.com/spring-calculator.html

On-line compression and double torsion spring calculator with blueprint. Now to take some measurements and count some coils. Measure deflection on torsion leg. I found several of these, some associated with spring companies. 10 or 12 different choices of wire. Wouldn't have a clue which is the best wire. Haven't seen any wire like Walther uses for the recoil but the hammer spring appears to be square, passivated stainless. Could be wrong, prolly am. M1911
 

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Discussion Starter #40
Hammer spring, it's magnetic, 0.0385" dia. square wire, 0.98mm; 0.2615" o.d. of coil, 3 coils, bottom leg 0.8535" long and rear leg, 0.428" long. Subtract 0.0385" x 2 from o.d. for i.d. 128 degrees arm to arm. But, this may be an over wound one??? I don't remember.

Now, someone apply that to the spring calculator and see if something similar exists.....get a blueprint too while you are at it. What kind of steel...??? I plucked one and couldn't get any kind of a note out of it and certainly not any Hendrix....so I'm thinking it is not guitar string. M1911
 
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