Replacing Hammer Spring

[govtcheez]

Someone in another gun forum suggested that I try a lighter hammer spring to lighten up the heavy DA trigger pull.

Anyone here have experience with this? If so, which weight did you go with? I want to go with the lightest possible without risking any issues.

Also, I was suggested this site:
http://www.gunsprings.com/Semi-Auto%20Pistols/CZ/75%20Series/cID1/mID16/dID91#838

Please let me know if you have any others that you think is more reliable/better.

Thanks in advance.

[Stuart]

13# or 15# ususally work across all the brands of ammo/primer
CZ Custom usually has them in stock

[hoot-]

Would anyone be able to answer a few quick questions for me?  I'm a pretty new handgun owner and I'm trying to figure out some of the mechanical basics.  From what I understand:

Recoil Springs
1) Recoil springs absorb the energy from the recoil (obviously), using that energy eject the spent cartridge, pick up another round from the magazine and push it into the chamber.
2) If one were to use too heavy of a recoil spring, the slide may not go back enough to pick up another round.
3) What happens if the recoil spring is too light?  Does the slide hit the back of the frame too hard and cause damage?  Are empty casings not ejected as reliably?  Is there not enough energy conserved to push the next round into the chamber?
4) Bullet grain plays a huge factor in appropriate recoil spring weight, right?  The lighter the ammo, the lighter the recoil spring?

Hammer (Main) Springs
1) Hammer springs dictate how hard the hammer strikes the primer.
2) Heavier hammer springs cause the hammer to strike the primer with greater force, increasing the chance that the primer will ignite.  The tradeoff is that the DA action will be heavier.
3) Lighter hammer springs, conversely, result in a gentler hammer strike, making it more likely for a round to not go off.  The DA action will be lighter.  Do longer firing pins just increase the chance that the primer will ignite?

Misc.
1) If the hammer is cocked, only the recoil spring has to do with how hard the slide is to rack.
2) If the hammer is decocked, both the recoil spring and hammer spring play a part in the force required to rack the slide (since racking the slide pushes the hammer into a cocked position.
3) What determines the pull weight of the SA?
4) Is there a reason that Wolff doesn't sell 13 lb. hammer springs?  Are they too unreliable?

Thanks in advance

[mkd]

 hoot you have the basic idea how these pistols function down pretty good.the recoil spring absorbs the energy of the spent case.too light the slide travel is more abussive to the pistol,too heavy and the case may not clear the pistol and load another cartridge.ideally one recoil spring will work for all loads of shells but that is not the case so they try to match the spring weight so that it will do a fair job at all of them.i for one have no intentions of running +p ammo in my 9mm.by elliminating the most demanding  cartridges you narrow the parameter that the pistol has to function in,thus you can fine tune the pistol for a less demanding working enviroment.i have owned my p01 for about 4 months and the first thing i did was lighten the hammer spring to 15lbs.i have on order a three piece spring kit that will lighten the hammer spring to 13lbs,and have a reduced power firing pin return spring,and firing block spring.in essence it will lighten the double action firing trigger effort even more.i also ordered a reduced weight trigger return spring that will lighten sa/da pull by approx 8oz.these modifications as well as the action being polished will lessen the effort needed for discharge as well as smooth out the feel while the trigger is being cycled.the recoil spring weight controls the energy from discharge,the hammer spring and related parts controls the strike to the primer,and the trigger and  action related parts control the weight,smoothness  and feel of the effort needed to discharge the pistol.  for now i have left the recoil spring stock even though the hammer spring being lighter weight will actually lessen the demand on the recoil spring itself.i have read her that you can judge the recoil spring weight you need by the distance it throws the spent cases after discharge for a particular load.

[hoot-]

mkd,

Thanks for the response.  This, of course, leads to more questions 

1) Does the trigger block in a CZ work like the one in a Glock?  Does the block move up when you depress the trigger, allowing the firing pin to make contact with the primer?

2) Will the 13 lb hammer spring be too light for igniting rimfire .22 ammo?  I plan on getting a Kadet kit in the future and want to make sure I don't go too light.

3) Did you get the three piece spring kit from CGW (SPGK-1)?  What is the difference between this and their Ultra-Lite DA Kit (UL-DA)?  Is it just the addition of an additional spring and the lengthened firing pin?

4) What is the significance of the different hammers from CGW?  Are they just machined to be buttery smooth?  Is the shape changed in any way?

[mkd]

hoot! the best advice i can offer is call david at cgw (schmecky here on the forum) or send him a private message.i was asking the same type questions not too long ago and he knows the answers.there are other places as well but schmecky is who helped me out.i also got the solid trigger pin for easy takedown, hardened firing block pin, and the slave pin and punch for the sear cage.he also was more than willing to tell me where to get the best bang for my buck on polishing the action.

[hoot-]

mdk,

I have indeed spoken with David of Cajun Gun Works.  He was very pleasant to speak with and answered all of my questions.  I ended up going with a 13 lb. hammer spring, reduced trigger spring, trigger pin, and decocker installation kit.  I asked to slightly alter my order (I had originally wanted a firing pin spring, as well) but, as testament to his speed, he had already sent it out.

No problem.  He threw in the spring for free and waived the shipping on the second half of my order.  All in all, it was a very pleasurable experience.  David is definitely a gentleman that I look forward to working with in the future.

[myles]

You'll need a 17 lb hammer spring or so to reliably ignite .22 LR.  A 15 lb may come close but you'll have an occasional failure to ignite - a second strike has always worked for me with a 15 lb spring and Federal Champion ammo.

I keep a 8 lb CGW hammer spring in my 85b and feed it only Federals.  Switching out the hammer spring when I put on the Kadet Kit takes only a couple of minutes - I keep a small screwdriver for the grips and a punch with the Kadet Kit.

[govtcheez]

I just received my hammer and recoil springs. I noticed that the recoil spring came with a firing pin spring as well.

Do I have to replace the firing pin spring, or can I just replace the recoil spring without having to worry about that? This is a fairly new pistol with about 600 rounds through it.