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Discussion Starter · #1 ·
As found
measurements and claculations to determine the force at battery and full recoil.  
these are basic spring calculations, with the assumtion of the highest strenght spring materil
i calc my used factory springs are 9.2#
the wolff 13 calcs at 11.8# and the stress in the wire is about 140% of factory
the wolff 15 calcs at 13.8# and the stress in the wire is about 150% of factory
the wolff 16 calcs at 16.4# and the stress in the wire is about 165% of factory
the stress at full compression is a factor in how many cycles are in the life of the spring.
The spread sheet for these calculations is below

First impression
the best findings for me was the solid lenght of all the wolffs are less than factory, thus the slide should hit the frame before the coils go solid.
Disappointed that the ends of the springs are not ground.  I can see the $1 OEMs just being closed, but for $8, they could have hit the ends with a grinder.  a few minutes with the file was able to flatten the ends.  the material is hard so a good file was needed

Trying them in the gun
one end of the inner springs are tighter than the other.  don't know if this intentional or the results of the coiling machine.  the tight end needs to go on rod first
the 13# feels pretty good just racking slide a few times
the 15# makes the slide more dificult to rack.  I consider my self experanced and can rack most any thing and this takes all of my effort.  however, I was not able to eject a live round
the 16# requires special hold on slide and push with grip hand.  the spring force is so great at battery that the friction on the barrel sliding up would hold it from going completely in.  Sling shotting slide helped
 

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Discussion Starter · #2 ·
Re: Wolff Spring calibration pack


chart explaination
'L1' would be the spring lenght at battery
'L2' would be the spring lenght at full recoil
'solid' would be the lenght of the spring when it is coil to coil, thus 'solid' less than 'L2' is good
'Load1' is spring force when in battery
'Load2' is spring force when at full recoil
'total load' is the sum of the inner and outer spring
 

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Discussion Starter · #3 ·
Re: Wolff Spring calibration pack

5 shots on each
Remington Green box 95gr MC L380AP

after only 5 rounds the springs free length reduced to about 85%.  as could be predicted, the higher stressed 16 reduced to 83%, where as the 13 to 87%
racking the slide and ejecting a live round was no problem even with the 16 now

recalculating the force now has
13 - 10.5#
15 - 11.9#
16 - 12.4#

the stress in the wire at full recoil is now down to about 125% of that of the used factory

as far as the flight of spent casings, holding the gun gansta style, they all landed 20' to 30' away, even with my worn factory, with the nearest being with the 16 and the farthest with the factory
 

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Re: Wolff Spring calibration pack Reveiw

WOW!! I do not know what to say except thank you very much for taking the time to accumulate all of this data, interpret it, and publish it in a way that even I can understand it.
 

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Re: Wolff Spring calibration pack Reveiw

+1. That's a lot of work to create and organize.

I'm wondering if using a higher strength spring creates a notable reduction in smilies? Did you happen to notice that when you ran the tests?
 

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Discussion Starter · #6 ·
Re: Wolff Spring calibration pack Reveiw

I didn't have a smiley prior (I have a little neoprine shim in the frame that forces the barrel to stay in contact with the slide)

I shot 2 rounds, check for smiley on the top magazine and the one chamber and did not see smiley with all 4 sets of springs  

Sorry but I don't have any indication the springs would help
 

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Re: Wolff Spring calibration pack Reveiw

Thanks JFB...super review...thanks again for all of your work and time on KTOG...much appreciated. :)

Boggs
 

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Discussion Starter · #8 ·
I've decided to carry with the 16# springs installed, even though I carry a mild round.  the BIG reason for me is the less solid lenght than factory springs, especially with the recoil rod guide nylon washer installed.

I popped of several rounds today with weak hand and no problems with limp wristing.

I would say the negative of the springs is clearing a live round from the chamber.  I can not throw the round clear, nor can I hold the slide at full recoil to shake the round in the slide palm.  I would think anyone having trouble loading a round could not use them.

the other would be that they MUST be shot for a couple rounds so they can take a set and loss a lot of thier installed force

the next concern will be their cyclic life.  I'm thinking there will be a rapid decrease till they yeild to allow working stress to normailize.  
 

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Tried the 16# out today and worked well, but beat up the cases a little bit. Noticeable gouging on the rim of the case from the extractor and dents/scrapes at the case mouth from banging on the way out. Still had a hard time finding my cases.

I'm not an engineer and still don't understand why there is a replacement firing pin spring. It sounds from your analysis that it is stiffer and thus will make it harder for the hammer to impart as much force on the firing pin, which I think would be undesirable for a Keltec.
 

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Discussion Starter · #10 ·
did you try to clear the chamber with the 16#.  It is all I can do ;)

I've heard the reason wolf provides the stiffer FP springs is to prevent slam fire since the slide will be returning at a higher velocity and the inertai of the fp could overcome the original FP spring.  :-/

I have though about testing to see how much inertia the FP could have, but not got around to doing any

edit to add a little testing

removed FP spring and shot 5 rounds, inspecting each chambered round. there was a very small contact mark on primer, but no slam fires. there is still more I hope to do if a get a chance, like cut FP spring to 0 force when installed and possibly making some wax or lead primer rounds

intertesting, after just 5 more rounds, the 16# wolff feel easier to rack :-/
 

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Okay, that makes since. I think I'm going to back to the factory or maybe the 13 pound. I definitely don't want a stronger firing pin spring in this gun.
 

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one end of the inner springs are tighter than the other. don't know if this intentional or the results of the coiling machine
The spring may be "progressively wound". This is a method used on some motorcycle fork springs that allows the spring to exhibit a progressive force when being compressed. A bit softer at first then getting harder as the compression increases. It is a way of getting a two for one characteristic out of the spring.
 

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Discussion Starter · #13 ·
380 Guy said:
one end of the inner springs are tighter than the other.  don't know if this intentional or the results of the coiling machine
The spring may be "progressively wound".  ...

It was only the end "closed coil" and less than 0.003" on the OD.  I didn't even use that resolution for the active coils (0.18") in my force calcs since that OD significance would be less than 0.1 pounds.

the coil pitch was constaint up to end 1 [sup]1[/sup]/[sub]2[/sub] coils where they were closed.  the "progessive wound" effects for closed coil ends was taking into consideration in my calcs
 

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hard to clear round

did you try to clear the chamber with the 16#. *It is all I can do ;)

I've heard the reason wolf provides the stiffer FP springs is to prevent slam fire since the slide will be returning at a higher velocity and the inertai of the fp could overcome the original FP spring. *:-/

I have though about testing to see how much inertia the FP could have, but not got around to doing any

edit to add a little testing

removed FP spring and shot 5 rounds, inspecting each chambered round. there was a very small contact mark on primer, but no slam fires. there is still more I hope to do if a get a chance, like cut FP spring to 0 force when installed and possibly making some wax or lead primer rounds

intertesting, after just 5 more rounds, the 16# wolff feel easier to rack :-/
i too have a hard time clearing a round the slide is sooooo hard to rack with a round in chamber , but not w/o one in chamber, it has (p11 9mm ) the org , spring in it , what do you suggest # spring that i could use. to correct this problem. ,
thanks
 

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ok, i know i am not the sharpest tool in the shed sometimes. so i am going to ask. unless you are trying to tune your gun to operate with extra power rounds, what is the purpose of changing the springs? i thought these kits were to tune your gun for +p loads.
 

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A heavier spring will give less felt recoil and also is easier on the firearm.I run the 16 lb. spring and the felt recoil is better.I put the 13 lb. spring in my wifes LCP and she loves the difference in recoil.Factory LCP spring is a lighter spring than P-3AT due to slide being heavier.Both guns still function flawlessly with stronger springs.
 

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thanks doublebarrel2. since i have both guns, i will put a calibration pack on my wish list for next time i place an order.
 
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