Trigger job and tuning of Sig P228 / 229 / Clones
The following applies to most P-series SIG pistols and clones (P228, P229 and P226).
The pistol featured is Norinco NP34 in 9mm (Sig P228 clone)
The following improvements / modifications were made to the pistol:
The end results.
I am quite happy with the results. The trigger pull and feel are now greatly improved. I tested it on the range numerous times - it shoots very well.
The process to get there
Disclaimer: Do this at your own risk.
I used Series 2 stoning fixture with the universal adapter for the hammer. I had to make a custom adapter for the SRT sear.
I followed this process, Keeping in mind that my goal is to polish, NOT to remove any metal:
The following pics illustrate the process.
1. Hammer's SA surface.
In the SA mode the corresponding mating surfaces of the hammer and the sear are already quite narrow. It is important to polish both surfaces without changing the angle of engagement or rounding the sharp edges. I strongly suggest using some kind of a specialized fixture because the surfaces are tiny and it is extremely easy to make a mistake and inadvertently change the angles.
The hammer is attached to the universal adapter held in place by two pins and the clamp. The adapter is mounted on the A side facing the user.
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The hammer is at zero. Note, how a fresh coat of dykem was removed evenly. From here I started using progressively finer stones to polish the surface.
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2. Hammer- DA surface
In this picture the hammer's position has been changed. I now repeat the process in order to polish the rear notch on the hammer (this area is engaged by the trigger bar during the DA pull)
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Next, I polished the area marked with blue color on the picture below. This is where sear rubs during the DA pull. I used dremel and a small felt wheel. Careful not to round any of the edges!
(the pic is a curtesy of the internet)
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3. Sear - SA surface
The sear proved to be somewhat of a challenge. I needed to affix the sear to the fixture in such a way that the stone could reach the mating area inside the hook.
I ended up milling a custom shaped adapter from a piece of aluminum as well as trimming some metal off my stone holder (compare with the picture above). I used a pin and a small machinist clamp to hold the sear firmly attached to the adapter without any movement at all.
The sear is attached to the adapter and the mating surface is covered with dykem. The new SRT sear is covered with phosphate coating which must be removed before the surfaces can be polished.
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Once the fixture was zeroed, I used a coarser stone to remove the phosphate coating and expose the metal.
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Then I polished the surface with progressively finer stones
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Here is a close up. The stone is sitting flat on the sear's mating surface
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4. Sear - DA surface
Finish the sear by polishing the areas shown. They are rubbing against the hummer's rotational area during DA pull. I used dremel to do this quickly.
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5. Trigger bar
The idea here is to smooth all surfaces where the bar touches other metal -
DO NOT round any corners!
After I polished the trigger bar I forgot to take a picture. So I grabbed one from the internet. I used dremel to lightly polish the areas shown inside the square.
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6. The slide
The inside of the slide (and at the bottom section which sits on the frame) has some crude machining marks. My goal was to only smooth those areas which rub against other parts. I first polished the bottom of the slide and then the rear section of the breach block.
I used 3M spray adhesive to attach 3 strips of sandpaper (400, 600 and 1000) to my granite surface plate. You can use hardened glass as an alternative. Then I put some oil on the paper and work the slide back and forth (don't put too much pressure and remember to wipe it clean when moving from one grit to the next. Check frequently)
DO NOT attempt to polish the rails on the frame! First of all, the frame rails on NP34 are already sufficiently smooth. And second, the frame is made of aluminum alloy which is hard anodized. Removing the anodizing will significantly weaken the frame!
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Here is the rear section of the breach block (this area pushes on the hammer when the slide travels back when the gun is fired ) I have also polished a small section of the hammer which is being pushed by the breach block.
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7. Hammer strut and pin
Next, I polished both the hammer pin and the areas on the hammer strut touching the hammer. While I don't expect a big improvement from doing this, every bit matters.
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8. Barrel crown polish
I then polished the crown using lapping compound and a brass lapping tool from Brownells
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9. Barrel and guiding rod polish
Finally I polished the barrel, the guiding rod and the corresponding barrel and guiding rod holes in the slide.
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10. Reassembly, cleaning, lubricating and testing
The last but not least, I put it back together and tested for safety.
The following applies to most P-series SIG pistols and clones (P228, P229 and P226).
The pistol featured is Norinco NP34 in 9mm (Sig P228 clone)
The following improvements / modifications were made to the pistol:
- SRT kit install (I used SIG's kit for P229 series)
- Trigger improvement in SA (polished the following parts / areas):
- The hammer's SA mating surface
- The new SRT sear's SA mating surface
- The front section SRT sear's hook
- Select areas of the trigger bar
- Trigger improvement in DA (polished the following parts / areas):
- The hammer's rotational surface (front)
- The rear notch on the hammer (engaged by the trigger bar's hook during the DA pull)
- The front section of the sear's hook
- 17 lbs wolf hammer spring (not yet installed - still deliberating)
- Polishing the crown
- Smoothing slide movement: (polish the following parts / areas):
- The bottom of the slide's rails
- The rear section of the breach block (where it pushes on the hammer when the slide travels )
- The barrel and the barrel hole inside the slide
- Spring guide rod and the corresponding hole inside the slide
The end results.
- SA pull is greatly improved. It is now crisp and reasonably light (measures at about 5 lbs.) For comparison, my tacops Sig P226 measures at 4.5lbs (factory)
- SRT works great (also very comparable to my P226).
- DA pull is also improved. It is now much lighter than it used to be (unfortunately I cannot measure it accurately because my gauge only goes to 10 lbs). I haven't yet changed the hammer spring for wolfe's reduced power one.
- The slide moves a lot smoother now. While it is as smooth as the sig, I have noticed that the recoil spring on the norc is also heavier than on the sig. I am considering installing the wolfe's recoil spring in addition to the hammer spring.
I am quite happy with the results. The trigger pull and feel are now greatly improved. I tested it on the range numerous times - it shoots very well.
The process to get there
Disclaimer: Do this at your own risk.
I used Series 2 stoning fixture with the universal adapter for the hammer. I had to make a custom adapter for the SRT sear.
I followed this process, Keeping in mind that my goal is to polish, NOT to remove any metal:
- Secure the part in the fixture
- Apply dykem paint to the surface being polished
- Place a fine stone in the stone holder (note all my stones are grinded at 45 degrees to allow easy access to tight places such as this one)
- Change the angle on the adapter until the approximate zero position is attained ("zero" is the factory angle of the surface being polished).
- Take a few of light passes with the stone and re-check to a see if the paint is being evenly removed from the entire surface (this would mean that the setup is at zero)
- If it is only removed from the front of the surface - the part is sitting too high and you need to lower the elevator
- If the paint is only removed at the back of the surface - it is sitting too low and you need to raise the elevator
- Keep adjusting re-applying dykem and using very light strokes with a fine stone until "zero" is reached.
- Now proceed with actually polishing the surface. Use a couple of strokes with progressively finer stones (I use 320, 600, 800 and stop at 1000)
The following pics illustrate the process.
1. Hammer's SA surface.
In the SA mode the corresponding mating surfaces of the hammer and the sear are already quite narrow. It is important to polish both surfaces without changing the angle of engagement or rounding the sharp edges. I strongly suggest using some kind of a specialized fixture because the surfaces are tiny and it is extremely easy to make a mistake and inadvertently change the angles.
The hammer is attached to the universal adapter held in place by two pins and the clamp. The adapter is mounted on the A side facing the user.
The hammer is at zero. Note, how a fresh coat of dykem was removed evenly. From here I started using progressively finer stones to polish the surface.
2. Hammer- DA surface
In this picture the hammer's position has been changed. I now repeat the process in order to polish the rear notch on the hammer (this area is engaged by the trigger bar during the DA pull)
Next, I polished the area marked with blue color on the picture below. This is where sear rubs during the DA pull. I used dremel and a small felt wheel. Careful not to round any of the edges!
(the pic is a curtesy of the internet)
3. Sear - SA surface
The sear proved to be somewhat of a challenge. I needed to affix the sear to the fixture in such a way that the stone could reach the mating area inside the hook.
I ended up milling a custom shaped adapter from a piece of aluminum as well as trimming some metal off my stone holder (compare with the picture above). I used a pin and a small machinist clamp to hold the sear firmly attached to the adapter without any movement at all.
The sear is attached to the adapter and the mating surface is covered with dykem. The new SRT sear is covered with phosphate coating which must be removed before the surfaces can be polished.
Once the fixture was zeroed, I used a coarser stone to remove the phosphate coating and expose the metal.
Then I polished the surface with progressively finer stones
Here is a close up. The stone is sitting flat on the sear's mating surface
4. Sear - DA surface
Finish the sear by polishing the areas shown. They are rubbing against the hummer's rotational area during DA pull. I used dremel to do this quickly.
5. Trigger bar
The idea here is to smooth all surfaces where the bar touches other metal -
DO NOT round any corners!
After I polished the trigger bar I forgot to take a picture. So I grabbed one from the internet. I used dremel to lightly polish the areas shown inside the square.
6. The slide
The inside of the slide (and at the bottom section which sits on the frame) has some crude machining marks. My goal was to only smooth those areas which rub against other parts. I first polished the bottom of the slide and then the rear section of the breach block.
I used 3M spray adhesive to attach 3 strips of sandpaper (400, 600 and 1000) to my granite surface plate. You can use hardened glass as an alternative. Then I put some oil on the paper and work the slide back and forth (don't put too much pressure and remember to wipe it clean when moving from one grit to the next. Check frequently)
DO NOT attempt to polish the rails on the frame! First of all, the frame rails on NP34 are already sufficiently smooth. And second, the frame is made of aluminum alloy which is hard anodized. Removing the anodizing will significantly weaken the frame!
Here is the rear section of the breach block (this area pushes on the hammer when the slide travels back when the gun is fired ) I have also polished a small section of the hammer which is being pushed by the breach block.
7. Hammer strut and pin
Next, I polished both the hammer pin and the areas on the hammer strut touching the hammer. While I don't expect a big improvement from doing this, every bit matters.
8. Barrel crown polish
I then polished the crown using lapping compound and a brass lapping tool from Brownells
9. Barrel and guiding rod polish
Finally I polished the barrel, the guiding rod and the corresponding barrel and guiding rod holes in the slide.
10. Reassembly, cleaning, lubricating and testing
The last but not least, I put it back together and tested for safety.
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