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CZ PISTOL CLUBS => CZ Polymer Pistols: P10, P-07, P-09 => Topic started by: Larry F on January 17, 2023, 01:29:39 PM

Title: CZ P-07/09 OEM Hammer modification question
Post by: Larry F on January 17, 2023, 01:29:39 PM
I'm in the midst of upgrading my CZ P07 pistol, and have shied away from doing anything with the hammer beyond polishing and assumed the only practical upgrade is a CGW or CZ Custom race hammer. 

However, ref http://www.brazeauracing.com/firearms/p0xhammers.html.  Anyone have experience with this particular OEM hammer modification and can provide meaningful input?   Thks, Larry

Title: Re: CZ P-07/09 OEM Hammer modification question
Post by: Earl Keese on January 18, 2023, 05:43:28 AM
 If you want to modify your P07 hammer, you don't need to build consensus,  just do it. Then, when it wears out quickly and becomes unsafe, you can replace it with a Cajun hammer.
Title: Re: CZ P-07/09 OEM Hammer modification question
Post by: Wobbly on January 18, 2023, 07:43:37 AM
If you want to modify your P07 hammer, you don't need to build consensus,  just do it.

True. The hammer doesn't care at all about consensus.
Title: Re: CZ P-07/09 OEM Hammer modification question
Post by: M1A4ME on January 18, 2023, 08:19:30 AM
I worked on one hammer, decades ago, for a Combat Commander.  Came out pretty good.  Zero issues afterwards.

But, it's not an easy thing to get right depending on exactly what you're doing.

A shorter shelp/notch where the sear sits should make for a crisper/shorter trigger pull.

It doesn't look/sound like you're going to be filing/stoning/polishing the surface where the sear contacts the hammer.  Just shortening that area to reduce the necessary distance the sear moves to release the hammer.

You'll need to be careful to insure the patch you leave, where the sear sits against the hammer is even from one side to the other.  You don't want it to be angled.

While the hammer surfaces are heat treated to make them hard and improve wear/increase the life of the hammer I have not idea if removing metal from the front of that surface will effect that corner where the untouched surface (sear notch) meets the vertical surface you removed metal from will wear quicker.  That's another thing you need to keep an eye on when you're done and using the pistol.  If it starts to round off or get burrs on it you'll need a new hammer.

The aftermarket hammers are made with that short shelf in that notch so the sear doesn't have to move far to release the hammer.  So the surfaces are heat treated where the sear contacts the hammer and that corner is heat treated on the vertical side above the notch/shelf.

Factory P07 hammer above and P07 hammer from CZ Custom below.

You can see the differences between factory vs. the other one.  Looks like what you're wanting.  The CZ Custom hammer will be properly heat treated where a modified factory hammer would not be - both sides of that corner where the sear slips off the hammer when you pull the trigger.

(https://i.imgur.com/SXF9Djkl.jpg)

Title: Re: CZ P-07/09 OEM Hammer modification question
Post by: Larry F on January 18, 2023, 08:59:50 AM
SCORE so far: 1 constructive comment and 2 Fanboys 2 cents worth. 

I'm pretty experienced in wear on parts and am really only interested in real user experiences in reworking their OEM hammers.  Thks, Larry 
Title: Re: CZ P-07/09 OEM Hammer modification question
Post by: Earl Keese on January 18, 2023, 09:51:24 AM
SCORE so far: 1 constructive comment and 2 Fanboys 2 cents worth. 

I'm pretty experienced in wear on parts and am really only interested in real user experiences in reworking their OEM hammers.  Thks, Larry
You mean one comment that said what you wanted to hear. Like I said, you wanna mod your hammer...mod your hammer. If you're as experienced as you say, what's stopping you?
Title: Re: CZ P-07/09 OEM Hammer modification question
Post by: Grendel on January 18, 2023, 10:12:51 AM
SCORE so far: 1 constructive comment and 2 Fanboys 2 cents worth. 

I'm pretty experienced in wear on parts and am really only interested in real user experiences in reworking their OEM hammers.  Thks, Larry

1. If you don't want to read contrary opinions, don't post your question in a Forum.

(Forum: a medium for open discussion)

2. No one here is privy to your level of expertise unless you tell them in your OP.

3. 23 posts and snarking off to other long time members and an administrator is unlikely to win you many friends here.
Title: Re: CZ P-07/09 OEM Hammer modification question
Post by: Larry F on January 18, 2023, 10:34:02 AM
Message recieved and accepted.  I generally research the effects of a possible change before beforehand to minimize redo's.  Inputs like M1A4ME's are very helpful and appreciated.  Other intuitively obvious observations are less helpful even to a novice CZ user such as me are less helpful and sometimes frustrating in cutting to the chase on an issue.  I overreacted and apologize to those affected, here and in prior postings.   Thks, Larry
Title: Re: CZ P-07/09 OEM Hammer modification question
Post by: Grendel on January 18, 2023, 12:03:40 PM
Thank you.

Hammer geometry and sear engagement is crucial. If you are confident and careful, with stoning and/or filing, it should be okay. Go slow and check often, I think is key here.

In my case, I would probably make sure I had a spare hammer on hand just in case I banjoed the original.
Title: Re: CZ P-07/09 OEM Hammer modification question
Post by: Wobbly on January 18, 2023, 01:28:11 PM
....just in case I banjoed the original.

Score so far, 1 offensive 2 cents worth.

This Admin owns a banjo and I am highly offended by your callous and insensitive comment. I'm a card carrying member of LBM (Loud Banjos Matter) and we just might serenade you tonight with 200 choruses of Dueling Banjos if you're not careful.

Larry, hope you sleep better tonight knowing you're not the only one suffering these indignities !
Title: Re: CZ P-07/09 OEM Hammer modification question
Post by: Larry F on January 18, 2023, 03:58:45 PM
Grendel - I buy your comment on how sensitive the sear and hammer engagement to change is. 

My first lesson learned was early on when I blued the hammer and sear mating surfaces and saw they were not fully engaging. I found the leading edge of the sear was cantilevered across it's face.  The guys at CGW indicated that this is common with the OEM sears and they true the leading edge of the sear and replace the sear pin as standard practice in their upgrades.  I did the same and the hammer roll back increased and the the trigger bar started catching on the disconnector.  CGW's input was that the action timing was right on the edge when the pistol was built and I had thrown it out.  My roller OD was measuring .218" and going to a .225" roller put it back to working right, i.e. a little change one way or another can have a big impact.

What I'm trying to accomplish with this particular pistol is to understand how CZ pistols work and decide if I want to replace my older 9mm Sig P228 pistol for the more powerful 40 caliber P07 as a carry gun or to pass it on to another party.  It's not a fair technical comparison as I had first hand support from Robert Burke (The Sig Armorer) in tuning the Sig pistol and and am working from distance in tuning the P07.  Sorry for upsetting of your regular posters as, as while I'm sure they were well intended, they were short on technical explanation.   Thks, Larry
Title: Re: CZ P-07/09 OEM Hammer modification question
Post by: M1A4ME on January 18, 2023, 06:23:12 PM
Larry, seems like I remember, a few years back, several members bought P07/P09 pistols that had "leaning hammers."  The hammer was not straight /perpendicular to the frame/slide.  Evidence was the hammer rubbing the slide of the notch in the back of the slide and just looking at it.  That might also cause an issue with the sear and hammer not being "square" with each other.  Something to take a look at when buying a P07/P09.

Grendel mentioned go slow and check.  While it takes some time to do and gets darned aggravating it results in a good outcome.  When I changed hammers in my CZ75 Compact I had the left side safety lever out of the frame to stone the cam on the shaft that blocks sear movement and back in to see if I'd removed enough metal to make it work without being sloppy right at 24 times.  I was getting so tired of it but the result was a safety that absolutely locks that sear in place with no slop between the cam, the sear at all.  Like they say, you can take metal off.  Putting it back on is darn difficult.

Good luck with it.
Title: Re: CZ P-07/09 OEM Hammer modification question
Post by: radagast on January 18, 2023, 07:13:14 PM
   Frame/hammer contact was just one of the problems I had with my 07, but at rest everything appeared normal. there was pressure pushing the hammer portside during the DA cocking sequence, so I followed the frame sanding process I found here in the forum to correct it.
   The improvement I got through polishing and sanding were so dramatic, I never felt the need to change any parts at all ! Now I'm anticipating replacement of the trigger return spring and the FP retaining pin since it's well over 5000 rounds.
Title: Re: CZ P-07/09 OEM Hammer modification question
Post by: Larry F on January 18, 2023, 07:56:23 PM
My hammer and sear seem to be pretty square with the frame and with each other.  I tried to check the sear pin and hammer pin separation distances on both sides of the rear insert and didn't measure much difference, the hammer looked to be sitting straight and doesn't show side wear, and the front of the sear ledge showed contact rubbing on about 3/4 across it's width.  I did smooth the sides the hammer and the insides of the frame per the tips from users. 

I talked with the guys at CGW and learned the leading edge of the MIM sear isn't machined and cants from one side of the sear to the other.  They stone the cant square on the upgrades they perform as well as on the pistols they sell.  They also change sear pin with one that reduces the sear's side to side play.  I did both but took too much metal off the sear's leading edge in getting it trued up with the hammer face and knocked the action out of time.

One of the reasons I've haven't installed a CGW hammer yet is, while it's a better design and material, I don't have a good feel for how much change it's going to make compared to how well I got the gun setup now.  What I didn't like about the SA trigger pull was it was too easy to trip the sear and fire a round before I intended to.  I've changed the OEM sear spring twice and I can ride the trigger without tripping the sear and the feel is closer to what I've been used to and the measured trigger pull weight is under 3.5#.  CGW has a new stiffer yet spring I'll check next.  I'm on about the 10th teardown and reassembly - not close to your record.

Also the CGW and CZ Custom hammers are used with the OEM sear which has a rounded edge and, at least in my mind, it may not live up to it's reputation as a fix all solution to my problem.  I've read that you have one and have a standard hammer build in another pistol that worked as well.  Can you expand on what your experience has been?  Thks,  Larry
   
Title: Re: CZ P-07/09 OEM Hammer modification question
Post by: M1A4ME on January 19, 2023, 08:55:29 AM
Larry, if you mean me:

I have two P07s (.40 DUTY and a 9MM new model) and two P09's (9MM and .40 S&W).  Only the P07 9MM has a replaced hammer.  The other three are still stock except for CGW reduced power firing pin block springs and trigger return springs and some stoning on the P09 9MM.

The P07 DUTY .40 came out of the box with a nice clean/crisp 3.5 lb. SA trigger pull and around an 8.5 DA trigger pull.  It is now down to just above 3 lbs. on SA and I haven't measured DA as I never use it.

The P09 9MM came next and had a pretty decent trigger out of the box.  Pull weights were similar to the P07 DUTY but not as crisp in SA.  I did some stoning on the sear and it helped some but didn't make it identical to the older P07.

The P09 .40 was next and the trigger is okay (don't remember the pull weights) but not as clean/crisp as the first two plastic Omega pistols I bought.  Not as accurate as the P07 either, close though.

The P07 9MM was last and had the worst trigger of the bunch.  Rather than do a bunch of spring changes and polishing, etc. I bought that CZ Custom hammer.  It helped but is still not as nice as the first P07 or the first P09.  Better that factory.  Good enough I never attempted to change out more parts or do more polishing. 

None of the four are as good as two of my steel framed CZs I replaced hammers in.  Nothing fancy about those two hammers but they are different than the stock factory hammers for a B model pistol.  They are the "repro" spur hammers sold by CZ USA   I have a Pre B CZ85 and like it.  I wanted to make my CZ75 Compact like a CZ85 and bought the spur hammer and CZ85 ambidextrous slide release levers and safeties and did some frame work to install those.  The notch in the hammer for the sear is really small/short/sharp comparted to the factory hammers.  No idea why but it makes for a 3 lb. SA trigger pull (with factory sear in the Compact and CGW adjustable sear in the CZ75B .40) so crisp the only way you can make yourself believe its really 3 lbs. is to do a few trigger pulls with a trigger pull ga.  Really, awesome trigger feel/pull.  The only thing I have lighter is the CZ Tactical Sport .40 (which is too darn light to carry and I have to be careful at the range with it, too).  The CZ75 Compact and CZ75B .40 have the factory hammer springs in them and still have a wonderful 3 lb. SA trigger pull.  I don't need anything lighter because (I now I keep saying it) it's so crisp it feels lighter.  It is the crispness that counts, for me.

The Omegas are different than the CZ75s inside and I really have not worked on my Omegas like I have the CZ75 types.

One more thing, while working with other brands/models of pistols the last 8 or 10 years I've found that my belief that a nicer trigger makes a gun shoot better groups really hasn't been true for me.  But I still appreciate/like a nice trigger.
Title: Re: CZ P-07/09 OEM Hammer modification question
Post by: Larry F on January 20, 2023, 04:43:57 PM
Thks, good input.  Helps firm up my opinion on how much better the CGW will work in Polymer Frame CZ's.  I've had quite a bit of interaction with the CGW guns on the changes I've made, problems I've run into, and problems I've created in improving my P07's action.  What I know about their hammer, relative to the OEM hammer, is:
-it's high carbon thru hardened (52 rockwell C) steel and more precisely machined compared to the OEM MIM, 45 (rockwell C) hammer with rougher surfaces and duller edges.
-the hook depth is shorter, the hook engagement angle was not changed, nor was the hammer pin's pivoting location
- they are used with OEM sear, with it's as-cast leading edge to be trued and the face roughed up rather than smoothly polished
-1911 performance projections are meant to be relative to other mass produced Polymer Frame and 1911 pistols.  They aren't claiming comparable performance to CZ's metal frame pistols, which can be even further improved with a custom sear, or to high end 1911's
-the custom sear has a different hook to sear face engagement but still keeps the original radiused secondary angle.

Most seasoned CZ users already know the above but I didn't.  My thoughts and opinion for what it's worth at this point are:
-I've made my S/A trigger break feel firmer and sharper and reduced my fear of firing a round before I intend
-CGW's hammer will further firm and sharpen the feel
-these changes will move my trigger action's feel from poor to good to better but not comparable with that of a good 1911 pistol.

I going to used my pistol as reconfigured for a while before adapting the CGW hammer.  Thks, Larry
 
 
Title: Re: CZ P-07/09 OEM Hammer modification question
Post by: M1A4ME on January 20, 2023, 08:05:35 PM
There's more to trigger pull than SA and DA pull weights.

Let me say up front, I don't pay attention to what I call slack - the distance rearward distance between where the hammer rests and where the rearward movement reaches a point where easy rearward movement stops.  My finger/brain work together without me thinking about it.  After the pistol fires my finger allows the trigger to reset the sear and then takes up the slack till rearward movement stops again.  In my P07 DUTY there is no creep/drag, etc.  The rearward movement stops and anymore rearward movement makes it fire.  After shooting other pistols the P07 is usually a surprise when I shoot it again.  I got really lucky when I picked that pistol up off the table at that gun show.

You've done the polishing of parts and that seems to help a lot with most pistols.  The Omegas haven't been around as long as the CZ75 pistols.  They haven't been thought of as being as accurate as the CZ75's.  Many people don't like the plastic framed pistols or trust them.

If you get a chance, look up some of Joe's video's on shooting his P09 9MM at 100 and 200 yds.  The P07/P09 can be very accurate.  They're just not pretty.  Even if the trigger pulls are not as customizable as the CZ75's they can shoot like them.

My M&P 2.0 5" 9MM taught me that a super nice trigger (Apex) doesn't make a poor shooting pistol shoot better.  Feels better?  Absolutely.  Shoot better groups?  Nope.
Title: Re: CZ P-07/09 OEM Hammer modification question
Post by: Larry F on January 21, 2023, 10:53:57 AM
I buy into what you're saying - the P07 feel is different from what I'm used to.  My interest in pistols started a few years ago when my wife suddenly got caught up in the concealed carry for self protection wave and wanted a pistol.  It caused me to sell one of my better shotguns and buy 2 Glocks.  Being mechanically minded, I progressed to Sigs and Walthers, doing some tuning on each, and finally to a Les Bear 1911, which I've left alone. 

My perspective of a good trigger pull has been that it be relatively light and have a sharp break. The P07 break is light but I think it will have at least some creep regardless of how much you tweak it because of the sear configuration and eccentric hammer rotation.  I'm confident I'll get used to it over time unless one of my kids pirate it.  The CGW guys have been particularly open and helpful as I've blundered along.   

I suspect what happened with CZ's Polymer pistol line is that they recognized the Polymer pistol wave and their business model target for this line is higher volume - lower margin rather vs the higher margin - lower volume philosophy of their Metal frame line and they have controlled major manufacturing capitol investment thru using current design technology and common or slightly modified parts - probably smart thinking.  However, it causes avid tuners to spend as much on upgrades as the paid for the pistol. 

P07 action parts don't line up, stay lined up and interact as well as they would in a rigid metal framed pistol and tuning becomes as much art as science.  Your, along with other experienced users, insights help as I grind thru a new learning experience.  Thks, Lary
Title: Re: CZ P-07/09 OEM Hammer modification question
Post by: M1A4ME on January 21, 2023, 12:22:02 PM
If you're one of those people that fall into this category:

The more you do, the more you learn.

You're in a good place.

Every time I think I'm getting "good" something I've not run into before pops up and smack me in the face.
Title: Re: CZ P-07/09 OEM Hammer modification question
Post by: Larry F on January 22, 2023, 11:04:55 AM
M1AME has me pegged-I am a learn by doing guy.    Didn't, and still don't, know much about CZ pistols when I got my P07 in a trade.  I thought it was a pretty rough gun but but only had a set of dust gathering golf clubs invested and thought I could make it function better without spending more than I could get out of it.  CGW's marketing info leads you towards being able to make it work like a 1911 pistol along and most forum postings are supportive of the claim.

I'm also a trust but verify guy.  I have yet to find a P07 or P09 using a race hammer locally do understand how well they really function.  The CGW guys have been pretty open when pressed about their 1911 claims - I have a mass produced Polymer pistol and can make it it comparable to comparable mass produced 1911's.  Dave at CGW says the shorter hooks on their hammer, truing the sear and roughing the sear face will make a real difference but I shouldn't expect to turn a sow's ear into a silk purse.  My local gun shop guys don't carry CZ's but have been interested enough to help me do a hands on comparison with their stock of 1911 pistols - mostly midrange Springfields and Tisas.  My DA is better than the Tisas and pretty comparable to the stock Springfields but the SA isn't as good.

I'll probably adapt a race hammer eventually but for now I'm going to use my gun with the modifications I've made and let it's performance settle on me while continue trying to find a fully modified pistol to check out.  I do apologize to other forum regulars as I've taken some of their inputs as opinion based and pressed for more detail on their hands-on experiences.  Thks, Larry
Title: Re: CZ P-07/09 OEM Hammer modification question
Post by: SI VIS PACEM PARRABELLUM on January 22, 2023, 11:36:20 AM
I would not even consider comparing the da/sa lockwork of a CZ or ANY other da/sa pistol to a 1911. They are 2 ENTIRELY different worlds and you will never be able to tune the slack that will be present in the da/sa system out. That is just a simple fact. The 1911 being sa only can be tuned to have nearly all take up and overtravel removed along with pull weights of sub 3lbs. Guns like CZ's Beretta 92's and their variants hammer fired Sig p-series guns and the like can definitely be dialed in far better than they come from their factories but 1911 ish? Never.
Title: Re: CZ P-07/09 OEM Hammer modification question
Post by: Earl Keese on January 22, 2023, 02:03:49 PM
There are 1911 triggers... and everything else. That's just the way it is. Trying to equal a good 1911 trigger with anything else is a fools errand. Like German Shepards and Belgian Malinois...you may prefer the shepard, but it will never match the Malinois.
Title: Re: CZ P-07/09 OEM Hammer modification question
Post by: Larry F on January 23, 2023, 10:26:49 AM
If I were to buy a new hammer fired polymer pistol I'd probably pick a 1911 Rock River Poly but I've got to work with what I have in hand - a used CZ P07. 
 
I'm OK, even with the obvious warts 1911 guys point out, with how P07 action functions now with the exception of how the trigger feels when I trip it in the SA mode.  I've used forum inputs in polishing and replacing parts, and tweaked a Wolfe mainspring to shift more of the DA stacking feel to the front half of the trigger's travel.  The SA break is still a rolling release but it's firm enough now that I don't inadvertently trip the trigger before I intend to.

I think there's 3 things left to move the needle on how the SA break feels before I sign off on upgrading this pistol:
- CGW's Red sear spring which was just  released.  It's their stiffest yet.
- Roughing the sear face as CGW recommends.  I've shied away from doing that up to now because I trued the leading edge of
  the sear early on and knocked the action out of time and I didn't like the basic idea of a rough sear surface.
- A new race Hammer.  I've held off because I don't have a good feel on what it will do.  I haven't found a modified P07 or
  P09 locally to check out first hand, The geometry differences with 1911's, and I have a general practice of not investing more
  into guns than I can get out of them. 

  What I have now is a better functioning pistol with adjustable sights, it's case, 2 extra magazines, and some spare springs. 
  What I've invested is a set of used golf clubs which I hung onto when I couldn't get a decent trade in allowance on a new set,
  $150 in parts, $35 in postage, a fair amount of elbow grease and buying a new hammer will put me over what I think the gun
  is worth in the market place.   

I'd appreciation any other suggestions.  Thks, Larry
Title: Re: CZ P-07/09 OEM Hammer modification question
Post by: SI VIS PACEM PARRABELLUM on January 23, 2023, 06:51:49 PM
I recently finished the mods on another P-07. I mount my sears in a fixture and only "square them up" so I don't generally run into timing issues. I have tried the CGW sear springs including the recently released red spring and I find I do not like them and the factory sear spring coupled with the CGW hammer and 18lb hammer spring give me the optimal da/sa pull or at least I get the trigger feel that I personally like. I always add the short reset kit as well. 
As to spending more on a gun than you can get for it if you buy a new gun like buying a new car you've already spent more than you'll ever recover. Hopefully you can continue to trade you less loved items and save a buck that way.
Title: Re: CZ P-07/09 OEM Hammer modification question
Post by: Larry F on January 23, 2023, 10:19:04 PM
Good info.  What problems do you run into when you install the short reset kit?  I've shied away from it because David at CGW indicated I probably wouldn't be satisfied after using Sig's short reset kit plus I don't know what else may be required to make it work right. 

I am a pretty frugal guy and I've continued driving my 1998 Pickup since new - to each his own.  Thks, Larry
Title: Re: CZ P-07/09 OEM Hammer modification question
Post by: SI VIS PACEM PARRABELLUM on January 24, 2023, 05:22:19 AM
No problems installing the SRS kit at all. Pretty much drops right in without issue. No it isn't the same as the SRS in a Sig but the Sig action is also totally different. I had many Sigs at one point and yep their SRS is outstanding but the Sigs didn't hold a candle to any of my CZ's as far as accuracy nor reliability-my own experience. The Sigs are gone and the CZ's remain.
I'm frugal as well my car will be 30 yrs old this year but I like to go all in modding my guns.
Title: Re: CZ P-07/09 OEM Hammer modification question
Post by: M1A4ME on January 24, 2023, 06:20:29 AM
I had many Sigs at one point and yep their SRS is outstanding but the Sigs didn't hold a candle to any of my CZ's as far as accuracy nor reliability-my own experience. The Sigs are gone and the CZ's remain. 

And that is why I'm still carrying that old DUTY P07 .40 after buying 14 or 15 other pistols since I carried it home.  I think the CZ75B .40 could give it a run for the money but the P07 carries better.
Title: Re: CZ P-07/09 OEM Hammer modification question
Post by: Larry F on January 24, 2023, 12:46:59 PM
I'm not an avoid shooter but the accuracy I'm seeing with my Duty P07 .40 pistol is better than I expected.  The pistol came with adjustable sights I've adjusted so the POA and POI intersect at 20 yds using 165 gr HST JHP ammunition.  I'm getting 3 shot bench rest groupings of 2.5" - 3.5" at this distance.  My reworked Sig P6 is identical and Sig P220 is only a bit better (2"-3") with carry ammunition on a good day.

My only quandary left is that it's SA break stills feels soft to me but isn't bad enough to kick the gun out of bed over.  Frankly, forum inputs vary enough that I'll find a tuned P07 or P09 pistol and make a direct comparison before I change it much more.  I live in the GSP SC area and have call back requests in at our local range and several gun shops.  Thks, Larry       
Title: Re: CZ P-07/09 OEM Hammer modification question
Post by: Sc0- on January 27, 2023, 08:12:00 PM
Just went through a P07 and P09, stoned flat surfaces flat, deburred other surfaces, and squared up a few edges, applied a tiny bit of molly when assembling.  Maintained all springs and didn't touch the slide components.  The above gave me a 4lb'ish very smooth single action trigger pull, very happy with the way they turned out...  (CMP requires a 4lb trigger for Service Pistol EIC matches.)  Normally I would say triggers don't matter much but for bullseye it can make a difference...

Have worked on plenty of other triggers, prefer to use factory springs to maintain reliability without overspending on aftermarket components.
Title: Re: CZ P-07/09 OEM Hammer modification question
Post by: SI VIS PACEM PARRABELLUM on January 27, 2023, 08:34:22 PM
Have worked on plenty of other triggers, prefer to use factory springs to maintain reliability without overspending on aftermarket components.
define overspending?
Title: Re: CZ P-07/09 OEM Hammer modification question
Post by: Earl Keese on January 28, 2023, 07:49:03 AM
I'm not an avoid shooter but the accuracy I'm seeing with my Duty P07 .40 pistol is better than I expected.  The pistol came with adjustable sights I've adjusted so the POA and POI intersect at 20 yds using 165 gr HST JHP ammunition.  I'm getting 3 shot bench rest groupings of 2.5" - 3.5" at this distance.  My reworked Sig P6 is identical and Sig P220 is only a bit better (2"-3") with carry ammunition on a good day.

My only quandary left is that it's SA break stills feels soft to me but isn't bad enough to kick the gun out of bed over.  Frankly, forum inputs vary enough that I'll find a tuned P07 or P09 pistol and make a direct comparison before I change it much more.  I live in the GSP SC area and have call back requests in at our local range and several gun shops.  Thks, Larry     
The mechanical accuracy of the P07/09 platform surprises a lot of new owners. They are capable of impressively small groups for a production pistol. The soft/rolling SA break is characteristic of the platform as well.
Title: Re: CZ P-07/09 OEM Hammer modification question
Post by: Larry F on February 02, 2023, 11:13:14 AM
I working to get my SA wall resistance to the point I think it's safe to use as a truck carry gun - not competitive shooting.  Where I'm at now is 7.5# DA measured trigger pull weight and the SA is at 4.25 #.  Of the 4.5# SA, I'm measuring 2.25# in take up to a wall and an additional 2# to break thru the wall.  My SA pull weight was 3# and I couldn't measure a wall with my RCBS spring scale.  To get the SA to this point I've worked thru the blue, the natural, and lastly the red CGW sear springs, 2 mainsprings and an over sized roller to reduce hammer roll-back to .008" measured at the hammer ring.

ScO - I'd say you're a better tuner than me with the results you're reporting.  Thks, Larry
Title: Re: CZ P-07/09 OEM Hammer modification question
Post by: Earl Keese on February 02, 2023, 05:34:45 PM
I working to get my SA wall resistance to the point I think it's safe to use as a truck carry gun
It was safe from the factory.
Title: Re: CZ P-07/09 OEM Hammer modification question
Post by: SI VIS PACEM PARRABELLUM on February 02, 2023, 07:03:31 PM
I have a question for Larry F. Are we talking about one P-07 or 2 p-07's that you have. Are we talking about the one mentioned in an early December post you paid your friend $250 for because he needed some Christmas cash or is this the one you mention in a January post that you traded an old set of golf clubs for???

https://czfirearms.us/index.php?topic=120503.0  post #14
https://czfirearms.us/index.php?topic=120890.0  post #4
Title: Re: CZ P-07/09 OEM Hammer modification question
Post by: Larry F on February 03, 2023, 09:28:14 AM
Good question - simple answer- my introduction to the CZ pistol world was thru horsetrading with a friend: progressed thru interest, offers, counter offers, buying agreement, second guessing, reversal, and then recognizing the other had something we both might be able to put to better use.

I see from your posting activities that you know your way around this pistol and would appreciate your input on another issue I've posted about and have yet to resolve.

My pistol had a outward bow in the polymer frame below the ejection port and had increased the frame to front insert gap that seems to be commonplace with this pistol.  The short slide stop spring leg was only partially seated in the frame causing the bow.  I made a quick fix by reseating the leg in the frame and pushing the frame back into shape as best I could.  I then realized the leg was still binding in the the cylinder it sits in and would probably back out as the slide stop was taken out and put back into place and the action's cycling back and forth could be amplifying the situation.  I pried the spring out of the frame and launched it somewhere in my shop.  I adjusted the new spring to fit in the the insert channel and the frame bushing and installed it by positioning the long leg under the front cross pin (took an notched screwdriver and 4 hands) as the last step to get a best practical fit.  I also beveled the leading edge of the slide stop pin so it slides under the spring with thumb pressure and touched the corner the spring crawls over when the pin is pulled out.  Lastly, my ejection distance was greater than I was comfortable with and I tried unsuccessfully to source a new 40 caliber recoil spring and am using a flat wire glock recoil spring and have trimmed it to produce a shorter ejection throw and maybe lessen impact loadings thru the slide stop pin.  I've now got the frame pretty much back into it's original shape and can only hope i've fixed the problem.

I've got a newer style front insert assembly the eliminates the L shaped leg and holding it in reserve.   

I know that MI4ME has an identical pistol to mine that he's used successfully with hotter ammunition and extreme ejection distance and hasn't had this problem.
Any thought on this issue and what I should consider?  Thks, Larry   
Title: Re: CZ P-07/09 OEM Hammer modification question
Post by: SI VIS PACEM PARRABELLUM on February 03, 2023, 09:46:09 AM
Interesting answer. Pretty good word salad anyway but no cackle at the end. You know you have 5 threads going regarding this pistol that could have been condensed into one and saved a bit of confusion. I answered part of this in the thread where you brought up the frame insert.
 You have an early DUTY model pistol and the long and short of it is there were issues with a large portion of them. The bulge issue was partly related to the leg on the slide stop spring but not all of it. CZ recognized a flaw in the polymer formulation on the early guns and it was rectified in the 2nd gen models along with several other changes including carry beveling the slide and frame, interchangeable backstraps, metal sights with a set screw on the front, nitride finish on the slide, and front serrations. I may have missed something but you get the idea.
So the bulge had a twofold problem.
As to the ejection issue CZ used the factory blue flat wire recoil spring both on the 9mm and the .40 S&W models. If your ejection distance is too far or too short then you simply increase or decrease the spring rate till it's acceptable.


https://czfirearms.us/index.php?topic=120640.0
Title: Re: CZ P-07/09 OEM Hammer modification question
Post by: Larry F on February 03, 2023, 10:29:56 AM
Thks for the quick response.  My tact in dealing with a problem is is break in down into smaller elements that can be addressed individually : i.e. the multiple threads.  I've read the 2nd generation improvement boiler plate and know the basics of recoil spring adjustment.  What I'm hoping for from guys like you is if there is something I've overlooked in fixing the frame issue as CZ has refused to exchange the frame for a replacement.  Thks, Larry
Title: Re: CZ P-07/09 OEM Hammer modification question
Post by: SI VIS PACEM PARRABELLUM on February 03, 2023, 10:42:46 AM
Thks for the quick response.  My tact in dealing with a problem is is break in down into smaller elements that can be addressed individually : i.e. the multiple threads.  I've read the 2nd generation improvement boiler plate and know the basics of recoil spring adjustment.  What I'm hoping for from guys like you is if there is something I've overlooked in fixing the frame issue as CZ has refused to exchange the frame for a replacement.  Thks, Larry
Well at some point mods will come along and put the stop to the multi-threads dealing with more or less the same issue, issues, pistol.
There is nothing more that you can do to that gun other than maybe install the upgraded front insert and hope for the other issues such as much worse frame bulge or the detaching of the trigger bar spring from the frame.
10 years ago CZ would have gladly replaced the ENTIRE pistol under warranty free of charge and they did many mine included. At this point they are under no further obligation as the five year warranty expired many moons ago.
Title: Re: CZ P-07/09 OEM Hammer modification question
Post by: Larry F on February 03, 2023, 11:34:44 AM
I have to keep reminding myself that I'm trying to improve a budget grade pistol and there is a practical limit on how much better I can make it and expect I'm close to that point.

Thks for putting up with my approach and style in using this forum.  Larry