The PPQ Rattle Explained

There’s been a few discussions about how the Walther PPQ gives off a rattle when you shake the gun, whereas the VP9 and many other guns do not give off a rattle at all, with some concluding that the PPQ is of lesser quality than other handguns such as the VP9.

This impression is somewhat disturbing as I’ve stripped both guns apart completely, and I noticed nothing that would indicate how one pistol is of superior quality in fit and finish than another gun.  In fact, I found the PPQ to be more accurate of a pistol.

So what’s the deal?

To get to the bottom of the issue, let’s first measure the actual frame to slide fit of each pistol, and see if it’s true that the PPQ is more “sloppy”.

VP9 slide to frame fit:

Rail thickness – 0.0700″
Slide groove opening – 0.0750″
Amount of play – 0.0050″

PPQ slide to frame fit:

Rail thickness – 0.0595″
Slide groove opening – 0.0620″
Amount of play – 0.0025″

So mechanically speaking, the PPQ has a tighter slide to frame fit and has less play involved.  Then why would the PPQ rattle?

The answer lies not in the pistol’s fit and finish, but how hard the recoil spring is pushing the slide against the frame when the pistols are in battery.

The first picture shows the position of the markers when the gun is in battery, I put a masking tape on, then cut the tape with a razor blade between the slide and the frame.

Then I took off the slide lock so that the recoil spring is returned to its neutral position held together by the guide rod:

Difference in distance between slide unlock and locked positions:

VP9 – 0.105″
PPQ – 0.02″

Having to travel 0.1 inch, the higher compression of the VP9’s slide against the frame means there’s a constant pressure pushing the slide up and away from the frame at all times.  In fact, it takes about 3lbs of force to push or wiggle the slide against the frame.  The PPQ on the other hand, barely applied any force on the frame, making the slide able to wiggle freely.

Does this difference in design determine fit and finish quality?  Obviously not.  It does raise the question of “would a difference in initial compression of the recoil spring make a difference in felt recoil”?  Now that’s a much more interesting question.  Almost everyone talk about how the PPQ has a stronger felt recoil than the VP9, but the bore axis on the PPQ is only about 0.1″ higher than the VP9.

Update: (July, 2016)

Having tried a soft recoil spring on my PPQ, I’ve noticed that there weren’t that much of a difference in recoil.  The fact remains that the PPQ has a stronger flip than the VP9.

But back to the worry over the PPQ rattle.  Conclusion here is that rattle comes from recoil spring placement and strength, not a sign of higher or lower quality on a polymer pistol.  Perhaps what’s more important are factors such as accuracy, trigger group, reset, and other factors that actually determine accuracy and longevity of a pistol.  All these categories combined still outweigh the higher muzzle flip on the PPQ.

PPQ – 4″ vs 5″, Light vs Heavy Trigger

Recently found that the Speer Lawman is incredibly accurate on my PPQ, so I took both my PPQ’s out to the range yesterday and had some fun with them, and did some completely unfair comparisons. 🙂

Nobody should be surprised that the 5″ gun can shoot better than the 4″.  One particular note is that it’s easier for my untrained finger to get a flyer when the trigger is heavier, which also shouldn’t be a surprise.

After 15 shots.  You can see that the 4″ is getting about 2.5″ group omitting that one flyer while the 5″ has a 2″ group with no flyers.  I suspect that the difference would be less if I’m shooting bench.  Afterall the trigger doesn’t affect mechanical accuracy, just let me get away with less discipline. 🙂
What’s interesting is that at 15 yards I can see the target a lot better, and being able to get great accuracy with the 5″ PPQ becomes a cakewalk.  I seemed to have struggled with the 4″, but it might be because my fingers were getting tired.

As many had pointed out already, the inherent accuracy of a 4″ vs 5″ gun is pretty much equal, and it all comes down to how the front sight being further away help with aiming, and I totally agree.  I think the 25 yard results is a much better representation, which is about a 0.5″ gain at 25 yards.

Someday I should compare two guns at the same trigger weight to be more fair. 🙂

Here are all my PPQ related posts – https://lanzerbot.wordpress.com/category/ppq/

Case Study – PPQ VS VP9 Trigger

This blog explores the reasons for the Walther PPQ’s great trigger and explains why PPQ has such a short trigger reset.

The Walther PPQ had received great reviews and a keen following as the great successor of the already solid P99 pistol.  I too, am one of the many owners impressed by the PPQ.  Though the flip on this pistol was high, the PPQ was surprisingly accurate, and the trigger easily lived up to the hype.  I opened up the pistol and was very impressed by how elegant its design was, and at the same time, noticed the potential for this pistol to have a light trigger that most hammer fired pistol couldn’t achieve. I thought this was what the new breed of striker fired pistol was all about.

With all the hype behind the VP9, I was happy to be part of the hype and be the owner of such a great looking pistol.  At the range, the VP9 was very soft shooting, and accuracy was there.  What bothered me was an uneven pre-travel, and the take up was much tougher than the pre-travel.  It’s a feeling I get with most hammer fired pistol.

After opening up the VP9 and looking through the VP9’s sear group, I noticed distinct similarities towards VP9’s sear and the internals of other striker fired pistols such as Glocks.  I tried lightening up the VP9’s trigger but quickly realized that I couldn’t do much without having to tune with the sear engagement angles and grind away metal.

The internals of both pistols are vastly different.

Since then I’ve decided to take a few photos to illustrate my findings between the two pistols.  Hope it’ll be useful or interesting for those of you who are curious.

The PPQ pistol

So let’s take things apart and go through the inner workings of both pistols:

The whole sear group comes off with the removal of one spring pin.  The sear group is actually very simplistic, yet different than most of the typical “hammer/sear” relationship. 

Update – turns out this simple design for a sear housing is patented (https://www.google.com/patents/US7472507)

Here is the sear responsible for locking the striker. The top arm (more like a hook) of the sear locks the striker in place, but that isn’t the sear’s engagement surface.  Instead, the right arm of the sear holds the sear engagement surface, and a separate lever swings back to release this sear.  This setup is made so that the pivot point of the sear is behind the direction of the striker’s force.  This simple design allows the sear itself to not take the blunt of the force from the striker pin.

Here are some observation on how the PPQ’s sear group works:

• With this design, the sear only takes in 1/3 of the striker’s force.
• The striker spring on the PPQ measured about 7.5lb.
• The striker’s contact with sear arm is 10mm away from pivot at an angle of 30 degrees
• This translates to 3.7lb being applied as torque on the sear arm itself (7.5lb x sin(30)), the rest of the force is decompression force handled by the sear’s joint
• The sear itself is sitting further away from the pivot, giving itself more mechanical advantage hence less force being applied at the engagement area. (10mm/17mm * 3.7lb)
• We have a striker at 7.5lb but at the sear, only 2.5lb of force is being applied, and assuming a friction coefficient of 0.16 for a lubricated polished steel surface**, the force it takes to move the sear’s lever is about 0.4lb
• With the trigger arm hitting the sear lever at around 10mm away from the pivot point and the sear engagement surface being at 13mm, it would take 0.6lb of force for the trigger arm to push disengage the sear lever.

** source for info (http://www.engineeringtoolbox.com/friction-coefficients-d_778.html)

The above observation got to have some mistakes or over-sight as I’m no physics major, but I hope it help illustrate how the general system works, and it’ll help make the comparison with the VP9 sear much easier.

Another easy way to see how much force is applied to the sear itself is to pull the trigger without the striker.  It takes 4.6lbs to fire my PPQ normally, and with the slide taken off, the trigger return spring and sear return spring contributes 4.0lbs of the trigger pull.  Meaning it takes only 0.6lb to break the sear.

This is the secret sauce to the PPQ’s short trigger reset – it is the only pistol where the trigger has a mechanical disadvantage towards pushing the sear lever.  The result is a short travel on trigger to break & reset the sear with sacrifice to trigger weight.  Other pistols need a mechanical advantage because their sears are so heavy.

Update – Walther holds a patent for this particular design (https://www.google.com/patents/US5701698)

Now on to the VP9

The VP9 requires a little bit more effort to have the sear assembly removed.  Besides the spring pin that holds the sear group in place, you also need to remove the slide release lever, and a spring pin that holds the trigger assembly in place.  Wish it’s a bit more straight forward to maintain.

Similar to other HK pistols, the VP9’s trigger bar also ride along the bottom edge of a guide rod which is the disengage rod.  It makes the trigger rod move up then down during the up take.  I mention this cause this part seem to add a tiny bit to the trigger weight, and it also causes a uneven trigger pull, which is not preferred for me as a shooter.

Now for the sear assembly.  

Here we have an L shaped arm whose function is to move the sear by transferring the horizontal force of the trigger arm to a downward force for rotating the sear downward.

The sear itself is a more common design that resembles a Glock pistol.  Primarily the sear’s pivot point is in front of the striker’s sear, and the sear engages head to head with the striker directly.  Other striker fire pistols including M&P Shield, LC9s, P320, XDM, SD9, Sigma, all carry the same principle.

Here are the observation on how VP9’s sear works:

• The sear is taking in 9+lb of force even though the striker is pushing at 7.8lb
• The striker spring on the VP9 measured at around 7.8lb.
• The striker’s contact with the sear is the engagement surface itself.  Therefore there are no mechanical advantage in play to reduce the friction placed on the sear’s engagement surface.
• The force needed to break the sear is the friction coefficient times the angular force from the striker, plus the force needed to push the striker backwards because the sear is sitting 11 degrees above the sear’s pivot point.
• Angular force is 7.8 x cos(11.7) = 7.63
• Striker’s push against rotation of sear is 7.8 x sin(11.7) = 1.54
• The total force on the sear’s engagement surface is 9.17lb, and if we assume a friction coefficient of 0.16 results in 1.42lb of rotational force required to break this sear.
• In the illustration above I raised the friction coefficient to 0.17, and it still didn’t result in the actual trigger pull force on the VP9.  Probably the angle of the sear engagement surface causes more friction than what I calculated.

This whole design strikes me as someone who wish to derive a hammer firing pistol’s design through a striker system.  The funny thing is, newer HK hammer firing pistols such as the P30 actually breaks that tradition and taking the sear engagement surface away from the hammer.  Unless Walther holds a patent with how their sear works (update: they do), it’s odd that HK would go with this design.

It takes 1.7lb from the trigger to break the sear on the VP9.  My VP9’s trigger is at 4.7lb, while without the slide, the trigger is at 3lb.  But you get the idea.  This setup of having a sear with such heavy force against it means you must be a wizard as a gunsmith to grind and polish your way to having a light trigger.   

Glock pistols actually have a trigger connector which allows trigger weight to be adjusted, though at the expense of increasing the creep because that design creates a mechanical advantage from the trigger bar directly.

The PPQ on the other hand, allows for adjustments to trigger weight and creep independently.  Read this article on how to add creep adjustment on your PPQ.

To adjust the trigger pull weight requires one simple spring change. Both mods are easy to perform and reversible.  Upon realizing the gun’s brilliant design, and also it’s impressive accuracy, I purchased a second PPQ in with the M1 frame.

At the end of the day, I do love my VP9 because it’s still the best looking polymer in my opinion, and the ergonomics is terrific, while being one of the softest shooting polymers I have.  I have plenty of guns whose accuracy doesn’t come close to the VP9.  HK did a good job with introducing the striker fired VP9, and I hope that they would rethink their sear design in later models.  As it stands, the PPQ’s sear group is by far more adjustable and potentially longer lasting.  I have yet found another pistol that shares the PPQ’s sear design.

Here’s a link to other PPQ related posts – https://lanzerbot.wordpress.com/category/ppq/

Putting the P99 adjustable sights on the PPQ

… results in disaster. 🙂 Perhaps not that bad, but the end result was no where as pleasing as my LPA sights on the HK P30L. The PPQ has a really slim top, so you can see how the sides of the sight really sticks out.  What really bugs me is that the rear of the sight also protrudes out of the slide by about half an inch.  That felt really unsightly since the back of the slide slants forward.  Here’s a small gallery of what it looks like.

When viewed from the bottom, you can really see how it sticks out.

Compared to the LPA sight for the P30L, the P30 sight is a great fit.  The rounded corners fit the profile perfectly.

Walther PPQ M2 Trigger Job

** (02/11/15) If you are interested in the PPQ, be sure to check out the PPQ case study on its sear mechanism

I’ve been hearing plenty of nice things about the trigger on the Walther PPQ, and it’s been a long wait for the 5″ version to be back in stock.  The new gun finally arrived today, and the trigger certainly didn’t disappoint.

PPQ’s factory trigger weight is 4.5 pounds, but unlike the 5 pounds trigger on my HK P30, the trigger on the PPQ is so smooth that it felt like a 3 pound trigger, with no increase in trigger weight right before the break, something the P30 and SR22 both couldn’t avoid.

If this is my first gun I would be perfectly happy and be shooting away with the stock trigger. But having done 5 trigger jobs already, I couldn’t help myself but to bring the PPQ’s trigger down to 2.5 pounds like all my other guns.

First I must say that I’m extremely impressed with the PPQ’s internal design.  Maintaining this gun is way easier than any of my other handguns because all the main parts are contained in a “gear box”.  After pushing one spring pin out, the gear box can be pulled out and you have instant access to all the main parts.  Hats off to Walther for this wonderful design.

* All the major components are easily accessible for cleaning just by pulling the gear box out.  Awesome design!

Like any new guns, there was a gritty feel as the trigger travels.  An issue easily solved by firing thousands of shots, or by polishing the parts that come in contact with the frame of the gun

Polishing The Trigger Bar

The trigger bar rides underneath the sear housing assembly.  I’ve colored the the part that requires polishing in silver in the picture below.

Here’s a photo of the trigger bar from the factory.  The part is stamped and you can see the stamp marks which can cause a lot of grittiness.  On the right is the same part after polishing with a fine sanding stone, a rubber polishing bit, then with polishing compound.

 

Another place to polish is the dimple on the side of the trigger bar, as well as the entire left side of the trigger bar.

Polished out the areas that cause the most friction.  Now the trigger travels smooth as silk.

Polishing The Firing Pin Stop

Since posting this guide 2 years ago, I’ve learned that some PPQ’s suffer from a gritty trigger not from the trigger bar, but from the firing pin stop that is riding too tight against its housing.  I was lucky enough to not have that problem, but I’ll post some pictures on how to remove the firing pin stop pretty soon.

Polishing The Sear

The sear engagement surfaces can be polished to further reduce the trigger weight.  Note that this part is a preference as some people like a smoother break, while some enjoy having more of a wall, or a bit more force before the break.

The engagement surface to polish is pointed below:

Lightening The Trigger

I’ve written a more updated guide on replacing the spring and lightening the trigger.  The guide is below:
PPQ 3.5lb mod

Reducing The Creep

Since first writing this guide I’ve came up with a fully adjustable and reversible method to reducing the creep on the PPQ.  The guide is below:
PPQ Adjustable Creep Conversion

This trigger job will make your PPQ perform unlike any other polymer pistol.  Many members of the Walther forum had made these mods on their PPQ and some are shooting on a competitive level with no failures.  I’m happy to see many getting the most out of their PPQ, and hope you would be amongst them.

Click here for more PPQ related posts