ES13Raven Posted January 21 Share Posted January 21 Several 2011s can run a really light (7-8#) recoil spring, still cycle fast, feed reliably and return to POA. CZ Shadows running 130pf loads - most competitive shooters run an 11# recoil spring. How are the 2011s able to run reliably with such a light recoil spring? Slide weight? The 2011 design? Are CZ Shadows capable of reliably running a 7-8lb recoil spring? What modifications would that take? Link to comment Share on other sites More sharing options...
tt350z Posted January 22 Share Posted January 22 (edited) Probably because 2011’s run much heavier mainspring, like #7, 19, 21. Most Shadows commonly run #11.5 to keep the DA pull weight down since their being used in DA/SA divisions. Edited January 22 by tt350z Link to comment Share on other sites More sharing options...
GeneBray Posted January 22 Share Posted January 22 (edited) 23 hours ago, tt350z said: Probably because 2011’s run much heavier mainspring, like #7, 19, 21. Most Shadows commonly run #11.5 to keep the DA pull weight down since their being used in DA/SA divisions. Think your comment is spot on. A typo on the #7 main spring? {Edit: Corrected "stop" to "spot". I can't proof read very well either.. } Edited January 22 by GeneBray Link to comment Share on other sites More sharing options...
tt350z Posted January 22 Share Posted January 22 22 minutes ago, GeneBray said: Think your comment is stop on. A typo on the #7 main spring? Sorry yea. Meant to say #17 Link to comment Share on other sites More sharing options...
ES13Raven Posted January 22 Author Share Posted January 22 16 hours ago, tt350z said: Probably because 2011’s run much heavier mainspring, like #7, 19, 21. Most Shadows commonly run #11.5 to keep the DA pull weight down since their being used in DA/SA divisions. I thought there wasn't a correlation between the hammer spring and recoil spring weights. Doing a quick search - it looks like the CZ factory hammer spring is 20#. Are you saying a very light recoil spring (7-8#) is possible with a heavy hammer spring? Link to comment Share on other sites More sharing options...
tt350z Posted January 22 Share Posted January 22 A heavier hammer spring does take more energy for the slide to start moving back. So in theory, you could lighten the recoil spring and not batter the frame. Again, I’ve never scientifically tested this, just my guess. Link to comment Share on other sites More sharing options...
GeneBray Posted January 22 Share Posted January 22 (edited) On a 1911, the recoil spring and main springs are compressed on recoil. Additionally, friction and inertia of the slide and hammer and its associated parts are over come, but IMO those forces are really too small to play much of a role in how the slide cycles. There is also the issue that the hammer spring is not directly loaded under recoil. There are some levers involved in the linkage of the hammer and strut to compress the hammer spring. It would take detailed drawing with measurements along with a refresher course in my physics classes from 55+ years ago to figure out how much force is applied to those parts. My guess is there is some mechanical advantage or disadvantage in the design. How much? No idea, but more or less than just the force needed to compress whatever pound spring is installed. Probably not significant with regard to the overall behavior of the slide. Except for a very small movement until the sear engages the hammer hooks, the hammer spring also affects the slide return to battery. How much? Very little IMO or less than that. What do those comments mean? The recoil spring is the primary force for returning the slide to battery. The hammer spring and recoil spring work together to control the rearward speed of the slide. Proper tuning of a 1911 to you as a shooter for a particular load (weight of bullet. bullet velocity, and powder brand and amount) may require changes both springs. I had an uncle (passed away years ago) who shot 1911s in bulls eye matches when in the Army during WW II and the Korean War. If my memory is correct, his competition pistol had one set of springs (hammer and recoil) for hard ball and another ofter wadcutters. I also believe separate barrels for both disciplines. Don't recall if he used separate hammer and sear wad cutters and hard ball or not. Would not surprise me if he did. Edited January 23 by GeneBray Edited typo in 1st line of last paragraph Link to comment Share on other sites More sharing options...
shred Posted January 22 Share Posted January 22 Lots of the geometry is different between the two-- how and how far they lock and unlock, slide weights, recoil lengths, etc, etc. Seems unlikely to be just one thing responsible. Link to comment Share on other sites More sharing options...
zzt Posted January 23 Share Posted January 23 Most 2011s running 7 or 8 lb. recoil springs are Open guns. Most 2011 slides are heavier than CZ slides. The lighter the slide the heavier the recoil spring for the same PF, everything else being equal. Link to comment Share on other sites More sharing options...
ES13Raven Posted January 23 Author Share Posted January 23 32 minutes ago, zzt said: Most 2011s running 7 or 8 lb. recoil springs are Open guns. Most 2011 slides are heavier than CZ slides. The lighter the slide the heavier the recoil spring for the same PF, everything else being equal. Staccato XC, VooDoo Priest come stock with those recoil springs and are not Open guns. Everything I’ve read is the opposite: the lighter the slide, the lighter the recoil spring (in general). Link to comment Share on other sites More sharing options...
shred Posted January 24 Share Posted January 24 The geometry is different. It's like asking why you can't put the same shocks on your VW Golf as a Ford Mustang. Plus the Stacatto XC has a comped barrel. Comps and barrel weights require lower recoil spring weights because that's a thing too. Vudoo is a custom gun with a bull barrel by default. CZ's mostly have skinny barrels. Link to comment Share on other sites More sharing options...
yigal Posted January 24 Share Posted January 24 5 hours ago, ES13Raven said: Everything I’ve read is the opposite: the lighter the slide, the lighter the recoil spring (in general). In which book did you read such things? Link to comment Share on other sites More sharing options...
ES13Raven Posted January 24 Author Share Posted January 24 2 hours ago, yigal said: In which book did you read such things? Lighter slide = less reciprocating mass. Less mass = less spring force needed to slow/stop the rearward moving slide in recoil. Less mass = less spring force needed to close the forward moving slide. Link to comment Share on other sites More sharing options...
yigal Posted January 24 Share Posted January 24 3 hours ago, ES13Raven said: Lighter slide = less reciprocating mass. Less mass = less spring force needed to slow/stop the rearward moving slide in recoil. Less mass = less spring force needed to close the forward moving slide. The whole theory is only about forward direction. Just forgot to mention that with a small mass and a weak spring there is a chance to get the broken slide in the face due to strong recoil. Don't forget to include in this theory also the negligible thing called impact. MV/T. Link to comment Share on other sites More sharing options...
zzt Posted January 24 Share Posted January 24 6 hours ago, ES13Raven said: Lighter slide = less reciprocating mass. Less mass = less spring force needed to slow/stop the rearward moving slide in recoil. Less mass = less spring force needed to close the forward moving slide. Only your first sentence is correct. All else equal, a lighter slide will be driven rearward at a higher velocity than a heavier slide. More effort is required to arrest the slide in the space available. More effort equals a heavier recoil spring. Here is an easy to understand example. A 1911 firing a load that requires a 16 lb. recoil spring. Tap the slide to mount a Picatinny rail, then mount a tubular red dot such as those used by bullseye shooters. You have added several ounces of weight to the slide. You have to drop to a 12 lb. recoil spring to get the now heavier slide to function. Another example. The slide of my Open gun was lightened from 13 oz. to 10.5 oz. Firing my 115 JHP @ 1520 fps major load requires a 10 lb. recoil spring. Firing a 115 @ 1150 fps factory load requires a 6v recoil spring. Link to comment Share on other sites More sharing options...
ES13Raven Posted January 25 Author Share Posted January 25 Do a Google search for: "slide weight" recoil spring You will find multiple sources that say lighter slide = lighter recoil spring. This article is an example: https://pistolwizard.com/guides/slide "Anytime you change the weight of the slide, experiment with different recoil springs so the pistol continues to function reliably. A lighter slide usually means lighter springs, and vice versa." Link to comment Share on other sites More sharing options...
GeneBray Posted January 26 Share Posted January 26 (edited) To me that doesn't seem correct. If every thing stays the same and you lighten the slide, the force exerted when fired remains the same and the forces to be overcome decrease and the mass moved is less. That means slide acceleration increases. Velocity is distance traveled divided by time. With faster acceleration and the distance traveled remaining the same, then velocity has to increase. Higher slide velocity may you need to increase the recoil spring weight. There are a lot of variable that come into play for the proper answer, but they all start with how much weight is removed. I know a lighter recoil spring in all my pistols results in brass being ejected further which is an indirect measurement of the slide velocity. The converse was also true -- the heavier the spring the close the brass ejected to me. Adding an optic to a production pistol required a lighter recoil spring to function. Until the recoil spring was lightened 1-2 lbs. or more there were frequent FTF. As the recoil spring was lightened, the FTF improved until the pistol cycled normally. Added: This mass and velocity which mean forces causes the muzzle flip since in most pistols the slide and barrel are above the hand(s). The above only discusses recoil. Assuming nothing changes but slide weight, when the slide stops and recoil spring starts pushing the slide forward the lower weight (meaning mass) of the slide will accelerate faster and to a higher speed then come to a fairly abrupt stop when the slides goes into battery. AKA muzzle dip. The control of muzzle flip and dip very shooter to shooter and, I think if studies with enough high speed video, may vary shot to shot. If you change the slide weight (i.e., mass), then the recoil spring may need to adjusted to the shooter preferences for how "snappy" the recoil feels, how much muzzle flip and dip the weight change made to the pistols behavior. There may be rules of thumb for which way to go. What I've discovered is make the change, shoot the firearm and see what happens. Then, if you decide you need to change the recoil spring, attempt to decide lighter or heavier. Change, and test. Note what you think worked best and then make changes in the other direction to see if like that better. Once you find what works, keep it make a records of the change(s), why, and you subjective, and objective reason(s) for making the change. If you change something else, then the process starts over again. Edited January 26 by GeneBray Added addition info since first entry did not address return to battery. Link to comment Share on other sites More sharing options...
zzt Posted January 26 Share Posted January 26 On 1/25/2024 at 1:47 PM, ES13Raven said: You will find multiple sources that say lighter slide = lighter recoil spring. That doesn't mean they are correct. They are not. Link to comment Share on other sites More sharing options...
yigal Posted January 27 Share Posted January 27 6 hours ago, zzt said: That doesn't mean they are correct. They are not. exactly. This theory is more suitable for Parker pens Link to comment Share on other sites More sharing options...
Sarge Posted January 27 Share Posted January 27 On 1/24/2024 at 9:50 AM, zzt said: Another example. The slide of my Open gun was lightened from 13 oz. to 10.5 oz. Firing my 115 JHP @ 1520 fps major load requires a 10 lb. recoil spring. Firing a 115 @ 1150 fps factory load requires a 6v recoil spring. Please define “requires” . I run 115’s at 1500+fps with lightened slide and run 8# variable spring Link to comment Share on other sites More sharing options...
zzt Posted January 27 Share Posted January 27 (edited) 11 hours ago, Sarge said: Please define “requires” . I run 115’s at 1500+fps with lightened slide and run 8# variable spring "required" to tune the gun properly. 10 lb. recoil spring, 18 lb. mainspring and 'open' radius on a Cheely firing pin stop contribute to a perfect return to zero after each shot. The gun wears a custom 3-chamber, 6-port comp with two 3/16" poppels in the comp in a V2 configuration. Load is 10.8gr AA7 under a 115 JHP. Added later: slide action with 7 and 8 lb. springs is too violent. Plus, the muzzle returns high. Edited January 27 by zzt Link to comment Share on other sites More sharing options...
Sarge Posted January 27 Share Posted January 27 2 hours ago, zzt said: "required" to tune the gun properly. 10 lb. recoil spring, 18 lb. mainspring and 'open' radius on a Cheely firing pin stop contribute to a perfect return to zero after each shot. The gun wears a custom 3-chamber, 6-port comp with two 3/16" poppels in the comp in a V2 configuration. Load is 10.8gr AA7 under a 115 JHP. Added later: slide action with 7 and 8 lb. springs is too violent. Plus, the muzzle returns high. Ah. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now