Functional reliability is the absolute foundation of every Chen pistol. It is first and foremost the overriding guiding principle as I craft each piece. The level of reliability tuning inside the pistol far exceeds the traditional efforts offered by the custom
Nearly every functional part in the pistol is tuned in some thoughtful way to enhance the pistol's reliability. Every dimension is taken into account and how they relate to each other. I look at not only the static, but dynamic relationship between the parts in the firing cycle.
Pages upon pages could be written about my reliability tuning process, but the following are just some highlights:
Starting with each component, a battery of critical dimensions are measured on custom made gauges and tools. I ensure that every single part is dimensionally correct before it even enters the build process.
Every critical part is Rockwell hardness tested to ensure that it is the correct hardness and metallurgically sound.
Frame and slide rails are uniquely modified. These modifications enhance smoothness of function and uniquely allow debris and lubrication clearance, while still enabling the pistol to lock up tight.
The frame feed ramp is precision fixtured and machined to optimal depth vertically and horizontally and with the correct radius. The geometry is optimized for 8 round magazines and modern hollowpoint ammunition.
The barrel throat is modified to provide extremely smooth feeding of all bullet profiles. The lead in is generous, and runs the entire circumference of the barrel throat, all the way up to the sides of the hood. This prevents shaving of case mouth material from ammunition not given enough taper crimp of the case mouth in the loading process. All lead in edges are broken and smoothed to enhance function. Mirror polish gives the final ultimate touch of smoothness.
The chamber is reamed with a custom ground carbide reamer, ground to my proprietary dimensions. My chamber dimensions provide a generous operating window for different ammunition in harsh environments, while still maintaining match grade accuracy. My reamer also features a series of interchangeable pilots which I custom ground in house in .0002 increments, ensuring an extremely high level of concentricity between the bore and chamber. Additionally, the chamber is cut on a precision lathe fixture using a floating reamer holder, in a method similar to that used by benchrest rifle makers.
All critical areas inside the pistol are deburred and polished. Just scratching the surface, this includes the slide frame raceways, slide bore, disconnector track, fire control area, trigger track, magazine well, barrel bed, inside dust cover...well just consider that any functional area inside the pistol gets my attention.
The breech face is extensively tuned. It is checked for proper geometry, squared and adjusted as needed. Lead in angles are cut, any steps or burrs from the manufacturing process are removed to enhance feeding smoothness. The timing of the release of cartridges from the magazine is tuned. The firing pin hole is given light chamfer. It is polished to a mirror finish, and left with a beautifully smooth, flat tuned surface. Along with a finely tuned extractor, this smoothness can really be felt when sliding a round up the breechface by hand. It is a glassy smooth feel as the round glides up the breechface and snugs up against the extractor hook.
The highest quality barstock extractors are used. The geometry of each extractor is carefully shaped, tuned and tensioned by hand for maximum reliability and durability. A spare fitted extractor is supplied with each pistol.
We use the very finest custom machined ejectors available. They are machined from pre-heat treated tool steel, hardened to RC 32. Their unique profile and geometry make for the absolute most robust ejector available. They are manufactured oversize, and are individually machined to each pistol.
Slide stops are tuned with some unique "tweaks" to enhance its function. A special multi-axis angled detent is cut into the rear of the slide stop which positively stabilizes the function of the slide stop. It prevents false lockback by holding the slide stop in the down position during normal firing. Another angle aids in the engagement of the slide upon firing the last round, easing the slide stop into the full "up" position, to fully and positively engage the slide when locked back. This has the added benefit of preventing the peening of the corner of the slide stop notch in the slide. It is modified to prevent walking out and tuned to prevent bumping from bullet noses. The lobe is also tuned to provide easy reassembly.
Again, the preceding are merely highlights of the elaborate process that I go through to be sure that I have done everything possible to ensure the reliable function of the pistol under all operating conditions. Before the pistol is finished, it is test fired with a minimum of 500 rounds of ammunition of various types, along with a large assortment of magazines. There is no "break in" period with my pistols. They do not leave my shop unless they are extensively tested, to the point that I would confidently put one in my holster and stake my life on it.
Copyright © 2017 Stan Chen Custom. All Rights Reserved.