A Dirty Little…

Ever since I got my first HK, I had no idea what a good trigger meant. Since then, I’ve been training exclusively with my 45 thinking that the trigger is pretty good and this is what a normal trigger should feel like. However, when I got my XD-S 45, I really never thought that this gun’s trigger was all that good (compared to my HK); especially for a striker fired gun. Then again, the XD-S was my first striker fired gun so what do I know anyway.

But what came to light for me was when I was cleaning the mud off my 45 from a tactical pistol class, I was using Simple Green to clean off the mud on the grips and along the sides. However, my dumb ass sprayed it all over the gun thinking that I was giving it a thorough cleaning.


Well I learned that my gun no longer works like it supposed to.

The trigger was awful. It was no longer factory smooth. I noticed that during the function test the trigger would stick really bad and would not reset. Even after I dipped the gun in FrogLube and even used Breakfree to re-lube the lower, I still had a really hard time staging my trigger.

It was as if the metal was stripped to bare surface, rubbing hard against each other, that at any moment, the friction would cause the gun to catch on fire.

So I decided to contact Sam over at HK and I pretty much got a “scolding”… Well, he didn’t really scolded me. But he should have.

“Avoid the use of chemicals on the trigger group… especially household cleaners. They will break down the lubrication about half way and the resulting combo will be something resembling ‘tar’.”

I knew at this point that I had no choice but to detail strip this gun and clean it all out. But I have no experience in doing so. I looked at sending my gun to Bruce Gray to do the work but honestly, his wait time was the reason why I passed. Even his expensive pricing wasn’t an issue at the time cause I was desperate. I was desperate because this happened a few weeks before my Costa Ludus HET1 class.

Also at the time, Sam was already leaving to teach some classes so he wouldn’t be available to work on my gun. So once again, I didn’t want to wait. Ironically, I ended up not doing anything to the gun up till now.

I ran the gun like it was for the remaining of the year in all of my classes. Sadly, while I know I’m not a good shooter, I will admit that this major FUBAR on my part, really did effected how I was shooting to the worst. This to me is the clear definition of what a bad trigger is. Not because it’s a 8-10lb double action trigger. But because it was really hard for me to stage the trigger.

I was using more pressure just to get it stage, in which in turn caused me to break my shots incorrectly. I was fighting my trigger and the end result was… well, missing my shots. It was at a point where I kept a bottle of FP-10 in my bag and I would lube the gun after every magazine reload. It was ridiculous.

For a couple of months, I ended up switching over to my other HK cause I couldn’t stand this one no longer.

I knew that at some point I needed to sit down and really strip this gun. But I was afraid cause I wanted the preserved the warranty. After I did some pricing analysis of shipping the gun out and paying for the repairs, I realized that the entire cost would be enough for me to just buy a replacement. So I opted to void the warranty and just do it myself.

So where do I begin?

I looked for some dvds that could help me with my issue, but no luck. No one produced a gunsmith video for the HK45 or the HK45C. I was forced to go to the forums and after several threads, I found American Gunsmithing Institute. They say that the USP and the 45 models are nearly identical and it strips down the same way.

I spent almost a full month watching the dvd and some other YouTube online videos, just to get myself familiar with the parts. What I liked about the dvd was that the instructor had a lot of knowledge about HK and the use of using a cutaway gun to show how parts work together. But that suck part was that I had other questions, like choosing the right lube and other small detailed stuff; ending with me turning to other resources. But overall, it was a decent reference point for me to start with, however, the video quality looks like it came from an old VHS Tape.

After I stripped the entire lower half, I saw so much gunk in there, I couldn’t believe how dead on Sam was. There was literally tar and other gunk in the lower receiver, it looked like cupcake frosting. However, I’m curious to know if this was also due to me sending 10,000 rounds through the gun. But due to the FUBAR, I will not know until the next 10K rounds.

Other than the gunk, the gun itself was fairly clean.

Now I will say that I ended up stripping this gun down twice within a couple of days. The first time I cleaned the gunk out and lubed the gun with FP-10, the gun, although clean, still kept rubbing itself like a car brake with no pads. You could literally feel the metal rubbing up on each other.

I had to ask Sam what lube does he recommend…


“Use a light oil as opposed to grease of any kind.”

Before that, I was using FrogLube and while it was ok on the slide and barrel, it really sucked ass for lubing the internal parts. Then again, maybe I didn’t use it right. When I say “use it right”, I’m referring to me not polishing the internal parts prior.

Since this polishing process was done to my AR, I speculated that applying the technique to a pistol would be beneficial as well… at least I hoped.

So I decided to go out and prepare my gun for some deep polishing. Still, I had to be careful!

HK USP Trigger Smoothing

I was reading that there were some areas on the gun that I needed to avoid. After all, I was also using a 600 grit sandpaper. So I was careful not to shave off excess metal. But for this process, I ended up using just my hands to do the sanding. Next, with my Dremel tool, set on low and using Flitz Premium Polisher I worked on cleaning my parts again. This time, I was starting to note a big difference. The parts were beginning to feel like glass. I was getting excited to wanting to put this all back together to test it out.

After I got done with it, I ran everything through the ultrasonic once again.

Waiting… and waiting… and this is worst than waiting on a microwave!

Finally, I started drying off the parts and this time, as I was drying off my gun, I can tell that it’s going to be smooth. The polished parts really felt smooth as glass. I was excited.

Now it was time for the a lube job…

This time around, I did something different. I ignored Sam’s advice and ended up grabbing a tube of Mil-Comm TW-25B. And I generously applied to the the parts and afterwards, wiped off the excessive lube. Yeah I decided to forego the FP-10 and FrogLube. And you know what? I’m glad I did.

While I won’t go into details here, but for a while, I was on the band wagon and tried out a bunch of other lubricants and oils when I first got my gun. Honestly though, I couldn’t tell the difference between any of them, cause I tend to clean my gun after every training class. In the end I will say that I narrowed my choices down to FrogLube and FP-10. However they didn’t really do as well as I thought it would when dealing with the internal metals.

The FrogLube failed miserably when I tried to use it to clean out the gunk in the gun where I had dumped the Simple Green. Still, were these a fair assessment of the lube? Probably not, considering that the parts were not polished back then. But honestly I don’t know now, considering that I really don’t want to take apart my gun and reapply each of the lube to test them out.

Sticking with the TW-25B, the end result of my newly cleaned trigger bar, sear, detent, catch plate, hammer, axle, and the remaining parts… the gun just felt like it’s factory smooth once again. I definitely think the polishing helped cleared out the gunk and the carbon. But for some reason, the TW-25B grease seems like it might be a contributing factor as well.


Overall, the lesson learned here is not to use Simple Green!

Unless you drop or dump your gun in the ocean, mud or whatever, I really don’t think there is a need for you to detail strip your gun for cleaning; unless of course you put through a shit load of ammo (like 50k) and never once cleaned it.

But proper maintenance and routine cleaning will and should keep your gun running nicely, especially the trigger. This experience caused me to understand really what defines a good or bad trigger. More so, this also showed me how my HK endured through all the shooting I did with the lack of lube and gunk in the gun.

  • Firearm Tutorials

    Good stuff. Thanks for sharing this. Great photos, you can really see the grime on that hammer.

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  • Vidya

    Great article!
    You saved me. I was just going to try some Simple Green.
    Do you think Break Free CLP alone would be good enough?

    • Beyond The Trigger

      If you are just doing general cleaning and maintenance, then yes, Break Free CLP or anything similar will work great. My only suggestion is once you find the cleaning & lube brand you like, that works for you, just stick with it for consistency. Sometimes, if you mix different types of lube chemicals (without removing the old residue), it could gunk it up a little more than normal. Thanks for reading!

      • Vidya

        Thanks very much!😀