10mm Witness recoil springs

[Rokkyt]

Good Day All-
Long time fan of the CZ platform here (75BD, 82, 2x52's, & a IMI baby eagle in 9mm).  I recently purchased a new 10mm (full size) Witness in wonder finish.  I've been doing a bit of research & I'm a little concerned with all of the reports I've been reading of cracked slides on the 10mm Witnesses.  I haven't had the gun out to the range yet, but I have purchase the Wolf springs calibration pack & installed the 22 lb spring. 
My question is - Am I making a mistake by installing this heavier spring?  Some of my reading here on the CZ forum indicates the the brunt of the recoil forces are in the barrel lug & locking pin & that adding a heavier recoil spring could potentially increase the chance of cracking the slide by increasing the force at which the slide returns to battery.
Any information or suggestions anyone could pass on would be greatly appreciated.
Thanks-
Bill

[Gary1911A1]

Although it would increase trigger pull weight a stronger mainspring would help slow the slide without slamming the slide close.

[todd f]

I too just installed the #22 wolff recoil spring. I haven't had a chance to fire it but wow it takes a firm grip to rack the slide. I read allot about it before making the decision to install the #22 spring. I haven't heard of any ill affects from doing so. I hope others will chime in. Thanks

[schmeky]

I have a question. . . . how is it Tanfoglio can build a really nice pistol from the ground up. . . . and can't get the recoil spring right?  Installing a too stiff recoil spring can cause problems. 

In an ideal world, the recoil spring would absorb all the recoil forces without transmitting the torque to the frame/slide stop pin just at the moment of full reward travel.  When returning to battery, ideally, the recoil spring would supply just enough momentum to quickly strip off the next round, allowing enough "rise" time for the next round to raise sufficiently for being contacted by the bottom leading edge of the slide.  Increasing the spring rate will alter the "dwell" time of the slide when it comes to a full stop in the full ejection mode.

Think of the recoil forces acting on the rounds still in the mag.  Some of this force acts on the column of bullets and can slightly depress the mag spring, when the slide has traveled fully reward.  Now it's a matter of timing; is the next round in the full up position before the slide begins it's forward return?  If not, you'll get failures to feed and rounds sticking up and getting caught between the breach face and barrel face. 

You also get an accelerated slide speed on return to battery that puts more stress on the frame and slide stop pin.  The frame is now absorbing more torque when the slide closes with a higher recoil spring rate.  I could go on, but I think you can see there is a lot going on.  If anything, I would reduce the recoil spring rate by a pound or 2, or better yet, leave stock recoil spring.  A lot of engineering went into the springs rate, number of coils per inch, and overall length. 

Lastly, a heavier recoil spring will increase percieved recoil.  Some folks falsely believe a heavier spring absorbs recoil.  This is negated on return to battery when the slide "rocks" the pistol forward at full lock up.

[todd f]

I have a question. . . . how is it Tanfoglio can build a really nice pistol from the ground up. . . . and can't get the recoil spring right?  Installing a too stiff recoil spring can cause problems. 

In an ideal world, the recoil spring would absorb all the recoil forces without transmitting the torque to the frame/slide stop pin just at the moment of full reward travel.  When returning to battery, ideally, the recoil spring would supply just enough momentum to quickly strip off the next round, allowing enough "rise" time for the next round to raise sufficiently for being contacted by the bottom leading edge of the slide.  Increasing the spring rate will alter the "dwell" time of the slide when it comes to a full stop in the full ejection mode.

Think of the recoil forces acting on the rounds still in the mag.  Some of this force acts on the column of bullets and can slightly depress the mag spring, when the slide has traveled fully reward.  Now it's a matter of timing; is the next round in the full up position before the slide begins it's forward return?  If not, you'll get failures to feed and rounds sticking up and getting caught between the breach face and barrel face. 

You also get an accelerated slide speed on return to battery that puts more stress on the frame and slide stop pin.  The frame is now absorbing more torque when the slide closes with a higher recoil spring rate.  I could go on, but I think you can see there is a lot going on.  If anything, I would reduce the recoil spring rate by a pound or 2, or better yet, leave stock recoil spring.  A lot of engineering went into the springs rate, number of coils per inch, and overall length. 

I wondered the same thing. I only bought one because others have posted that they thought the recoil spring being of inadequate strength somehow caused the slide to crack. I installed the one I bought and I will tell you what, I don't like the feel of it while racking the slide. I don't plan on shooting heavy loads in this pistol. I dont shoot heavy loads in any of my semi auto's. I think I am going to take your advice and try the stock one With moderate loads and see how it functions. Your response is appreciated.

[Rokkyt]

I have a question. . . . how is it Tanfoglio can build a really nice pistol from the ground up. . . . and can't get the recoil spring right?  Installing a too stiff recoil spring can cause problems. 

In an ideal world, the recoil spring would absorb all the recoil forces without transmitting the torque to the frame/slide stop pin just at the moment of full reward travel.  When returning to battery, ideally, the recoil spring would supply just enough momentum to quickly strip off the next round, allowing enough "rise" time for the next round to raise sufficiently for being contacted by the bottom leading edge of the slide.  Increasing the spring rate will alter the "dwell" time of the slide when it comes to a full stop in the full ejection mode.

Think of the recoil forces acting on the rounds still in the mag.  Some of this force acts on the column of bullets and can slightly depress the mag spring, when the slide has traveled fully reward.  Now it's a matter of timing; is the next round in the full up position before the slide begins it's forward return?  If not, you'll get failures to feed and rounds sticking up and getting caught between the breach face and barrel face. 

You also get an accelerated slide speed on return to battery that puts more stress on the frame and slide stop pin.  The frame is now absorbing more torque when the slide closes with a higher recoil spring rate.  I could go on, but I think you can see there is a lot going on.  If anything, I would reduce the recoil spring rate by a pound or 2, or better yet, leave stock recoil spring.  A lot of engineering went into the springs rate, number of coils per inch, and overall length. 

Lastly, a heavier recoil spring will increase percieved recoil.  Some folks falsely believe a heavier spring absorbs recoil.  This is negated on return to battery when the slide "rocks" the pistol forward at full lock up.

Thanks Schmeky - That was very much the type of response I was hoping to get. 
But, back to the original problem - Has anyone heard much about the cracked slides on the 10mm?  Has this been on full sized or compact guns?  Stock or heavier springs?  Wonder vs Blue finish (Possible embrittlement of the slide?)? Factory or handloaded ammunition?  I notice that the slide on my gun appears somewhat "lighter" built than earlier Witnesses - It appears to be more rounded in profile than the earlier "slab sided" slides. 
Any thoughts folks?

[Rod Slinger]

schmeky.....Your understanding of the auto-pistol is excellent.  In fact (on this topic) you are where I  was in the early 80's, that's 1980's,  I was building guns for my own use in  pin and combat matches.  Back then everyone wanted light hammer springs and light recoil springs.  Two things happened to bring me to my current way of thinking.   I started seeing guns with damaged barrel and slide locking lugs, and battered frames.  The second and most important event was meeting the pistol smith who was to become my best friend and mentor.  Much of what you read that I post is a direct result of his teaching.

schmeky You asked "how is it Tanfoglio can't get the recoil spring right"  The answer is that the recoil spring they install in their pistols is exactly right for there needs.  Lets look at the 9 mm.  Tanfoglio needs their 9 to be able to function with a 90 gr. bullet moving a 1100 vel.  with this same spring the gun will function with 147 gr. bullet moving at 1300 vel.   By doing this they keep down the number of guns returned do to failure to feed.  I hope none here think that shooting this 9 with 147 gr. +P+ ammo is a good idea with the factory spring.

Slide cracking.  As for as I can tell all of the slides that have cracked on the new Witness were using factory springs.  If I am wrong on this please let me know.  I doubt that increasing recoil spring weight would have saved any of these slides from cracking. 

schmeky please allow me to expand on your explanation of the auto pistol.   There are four springs that come into play in the cycling of the pistol.  Hammer spring, Recoil spring, Firing pin spring and Mag. spring.
Upon firing the pistol the recoil spring, hammer spring and to a lesser extent the mag spring all help to slow the slide down in its rearward travel.  In forward travel the mag spring and ammo being striped aid in slowing down the slide as it is returned to battery.  The main reason why it is a bad idea to continuously drop a slide on an empty chamber.

schmeky You quoted "Some folks falsely believe a heavier spring absorbs recoil."   Well I happen to be one of those folks.  The shooters hand, wrist, the rest of the body will absorb the force of the slide regardless of what weight recoil spring is used.  The heavier spring will spread out that force making it more of a push than a slam.  This is one reason people believe automatic shotguns kick less than there fix breech guns even when the auto weighs less. 

I believe you should use the heaviest recoil spring that will give you 100% reliable feeding for you grip and ammo.  The key word is 100%.  Only by experimenting will you know what weight spring is the right one for you. 
I install a lot of Wolff recoil spring,  In fact Wolff has me on dealer pricing.  Many of my guns have 10s of thousands of rounds through them and no one has come back to me with a recoil spring related problem. 
I guess as long as it is working so well I will keep doing what I am doing.   R S
  R S

[schmeky]

R S,

I respect your input.  I have been proven wrong many times, and I have always made it a point to never treat an opinion as a fact.  I agree when you state the frame/slide would have cracked regardless of what recoil spring was being used.  You don't have to look long to see cracked frames in virtually any auto loader, Glock, S&W, Colt, Springfield, CZ, etc.  Quality control is only as good as the person(s) overseeing the process and metallugy, proper hardening/surface treatment, and machining (sharp edges can produce stress risers), reloaded ammunition, all enter the equation.  Sometimes things just happen.

If memory serves me, it seems most of the Witness problems are with the 10mm, which is a very high pressure round.  I need to look up the SAAMI operating pressures for the 10mm.  The 10mm is offered on the same platform as the 9mm.  I have a feeling Tanfoglio should have built the 10mm on a more robust frame/slide.  Browning increased the slide thickness and beefed up many components to go from 9mm to .40 in the Hi-power, and the .40 is basically a "10mm lite".

As far as the heavier recoil spring reducing felt recoil, I gleaned this from "1911 Tuner", a well respected gunsmith that posts on the High Road Forum regularly.  I'll see if I can dig up some of his posts on this matter.  He provides a really good detailed step-by-step analogy of the forces a to heavy recoil spring imparts on felt recoil. Not saying your right or wrong, I just need to back up my alligator mouth to cover my hummingbird b_tt.

Your points are valid and I'm glad you mentioned dropping a slide on an empty mag; a big no-no.  Your comments are excellent.

[ReloaderFred]

I have never cracked a slide on any of my Witness pistols, but they are all the older models.  Some have had Sprinco Recoil Reducers installed, and some haven't.  I did shear a slide stop in one of my 10mm Witnesses with the factory spring installed, and no buffers, etc., which is one of the reasons I started installing stronger springs and Sprinco units in my guns.  For the 10mm, I've settled on 20# recoil springs, and that works for me.

I believe the factory has set up their 10mm pistols for the factory ammunition that is being loaded these days, which is really just barely above .40 S&W ballistics.  If you're going to shoot ammunition that is in the same catagory as the original Norma loading, then you're going to have to increase the power of the recoil spring, use a buffer or Recoil Reducer.  A fully loaded 10mm has a lot of energy, and the machine surrounding all that energy has to be configured properly to contain and function with it.  In my humble opinion, the factory springs aren't up to handling fully loaded 10mm rounds on a continuous basis.

Hope this helps.

Fred

[vstromrider]

Can any one tell me what lbs the factory recoil spring  in the 10mm full sized polymer weapon is.

[jwc007]

Can any one tell me what lbs the factory recoil spring  in the 10mm full sized polymer weapon is.

The Factory Recoil Spring for a full sized 10mm Witness is rated at 18 pounds, when new.

[Gary1911A1]

Can any one tell me what lbs the factory recoil spring  in the 10mm full sized polymer weapon is.

The Factory Recoil Spring for a full sized 10mm Witness is rated at 18 pounds, when new.

I believe you, but mine didn't feel that strong to me. It felt like they used the same spring they used for the 9MM.

[jwc007]

I believe you, but mine didn't feel that strong to me. It felt like they used the same spring they used for the 9MM.

That would definitely be undersprung for full power 10mm Ammunition, but not too bad for the 10mm Lite Factory Ammunition that prevails.  I would run at least a 16 pound Recoil Spring even for Factory 10mm Ammunition.

[RBSmitty]

I don't know about the new Witness pistols, but the .45 and 10mm pistols I bought 4 years ago or so had a larger frame than the 9mm/40's did.  There are separate conversion kits for the 2 different frame sizes for 9mm & .40 cal.

[hardluk1]

 I had a factory shooter tell me to use a short piece of stock 1911 recoil spring to cut down an slid into your stock spring to slow down the rear motion an to keep from over powering forword movement ,for me it was to control brass ejection distance but it also does the samething youall are working at with out slide or frame damage from a heavy spring. Start with a stock 1" piece of 1911 sring and keep cutting and try it till you can pull the slide and chamber a round. My 40s&w ended up with a piece of spring about 1/2" long and so far works real well at reduceing ejection of brass from 20 to 10 or 12 feet and has made for a softer shooting pistol. I put the piece of spring right in front of the recoil lug on the recoil spring would stop at full compression. I do keep my wire cutters with me in my range bag so if a have a feed problem i can cut a bit more off till it has no problems . I have shot about 100 round with it in and like it.