The first surprise came after I returned home from California.

I had just picked up my new Grip+ stock for my Blaser F16 from Sai Chang in Hayward, California, and I was eager to get the gun back on familiar targets. I am a professional physicist, so I naturally like measurements, instrumentation, and using technology to understand what is really happening. In shooting, that means I do not want to rely only on feel or memory when I am trying to evaluate a change. I want data.

Like many shooters who use technology as part of practice, I mounted my ShotKam expecting to review my shots afterward. I wanted to see what had changed, how the new sight picture looked, and whether the stock felt as good at home as it had during the fitting process.

When I reviewed the videos, something was wrong.

My second shots were missing. Not the targets. The recordings.

On pairs, the ShotKam captured the first shot but not the second. The explanation turned out to be very interesting. The Grip+ stock had changed the recoil signature of the gun so much that the ShotKam accelerometer was not registering enough movement to trigger the recording of the second shot. The first shot was still captured because the camera had already armed during the mount, but the reduced recoil impulse after the first shot may not have been enough to trigger a separate second-shot recording. For someone who loves measurements, that was fascinating: the first evidence that the stock had changed the gun was not just how it felt in my shoulder, but how it appeared to the sensor. That was my first real indication that this stock had not merely changed the way the gun looked or fit. It had changed the way the gun behaved.

Recoil is simple in concept but important in practice. When a shotgun fires, the shot charge and wad are driven forward through the barrel. At the same time, the gun moves backward into the shooter. That rearward movement is recoil. With a conventional stock, much of that force is transferred directly into the shooter’s shoulder, cheek, and hands. It happens quickly, but the sharpness of that impulse affects comfort, recovery, and the ability to make a controlled second shot.

The Grip+ stock changes that experience through its piston-based recoil system. The gun still recoils, of course. Physics has not been repealed. The recoil is not eliminated; the piston changes how that momentum is delivered by reducing the peak acceleration and spreading the impulse over a slightly longer time. Instead of the full impulse being transferred sharply and immediately, part of that movement is absorbed and spread out. The result is a softer, more controlled push rather than a sharper hit.

That matters to the shooter. In my case, it also mattered to the ShotKam, even when set to its most sensitive setting.

The missing second shots became the perfect opening lesson for this entire process: the Grip+ stock solved two different problems, and it solved them in two different ways. The piston system changed recoil. The custom geometry changed point of impact. Both mattered, but they mattered differently.

Two Problems, Two Solutions

It is tempting to describe the Grip+ stock as a recoil-reduction system. That is true, but it is incomplete.

The stock did two separate things for my Blaser F16. First, the piston system changed recoil. It reduced the sharpness of the recoil impulse and made the gun feel softer and more controlled. Second, the custom geometry changed fit. That changed my sight picture, corrected a high-shooting tendency, and improved how the gun came to my face and shoulder.

Those are related benefits, but they are not the same benefit.

What impressed me most was that Grip+ is much more than a custom stock shop. The entire process is built around a digital manufacturing platform. My fitting began online, continued through digital measurements and CAD modeling, allowed me to review and approve the design before production, and concluded with CNC manufacturing and live-fire validation. Rather than adapting myself to a factory stock, the entire process was focused on designing a stock that adapted to me. That philosophy distinguishes Grip+ from the traditional custom stock approach.

The Grip+ piston changes the recoil signature measured by the ShotKam accelerometer. A conventional stock transfers a sharper rearward acceleration spike to the shooter, while the Grip+ piston spreads that impulse over a longer time and lowers the peak acceleration. The result is softer felt recoil and to my surprise resulted in a first-shot recoil signal that fell below the most sensitive ShotKam trigger threshold. This resulted in no second shots being recorded by the ShotKam after the stock was replaced with the Grip+.

My Blaser F16 is an excellent shotgun, but even an excellent shotgun has to fit the shooter. A factory stock is built to fit a range of shooters reasonably well. A custom stock is built to fit one shooter specifically. My goal was not simply to make the gun more comfortable. I wanted the gun to come up more naturally, point more honestly, and shoot closer to where I was actually looking.

Before the Grip+ stock, my gun tended to shoot high for me. That meant my sight picture had become part of the problem. I had adapted to the gun. Like many shooters, I had learned little compensations without fully realizing it. My eyes and hands knew that the gun printed high, and my shooting adjusted around that fact. That can work for a while, but it is not the same as having the gun fit correctly.

The Online Fitting

The process began remotely with an online fitting session with Sai Chang. This was not simply a matter of sending in a few measurements and waiting for a stock to arrive. Sai provided instructions for capturing the right images and measurements, using both the online video session and still images taken from that session.

The point was to understand how I actually mounted the gun: where my eye sat relative to the rib, how my head contacted the stock, how the gun aligned when I brought it to my face and shoulder, and whether the gun was naturally straight or tilted in my hands.

Measurements from the online fitting session. Sai Chang uses modern tools and techniques to accurately measure my shape and the needed stock dimensions. The big one here was the need to take 1 cm (10 mm) off of the comb.

One of the most important findings was that my comb needed to be lowered by about one centimeter.

That may not sound like much, but in shotgun fit, one centimeter is significant. The eye is effectively the rear sight on a shotgun. If the comb places the eye too high above the rib, the gun will tend to shoot high for that shooter. Lowering the comb changes the relationship between the eye, the rib, and the target line.

The fitting also revealed a large cant in the gun.

Cant is the tilt of the gun when mounted. A shooter may feel as if the gun is mounted straight, but the barrels may actually be tilted off vertical. That matters because a canted shotgun does not move through the target line in the way the shooter expects. It can change the visual relationship between the barrel and the target and can contribute to inconsistency, especially on targets that require a clean move along a vertical or angled line.

The mounted-gun photo showed a noticeable cant in the mounted gun: the top and bottom barrels were not vertically stacked. Using the apparent barrel centers, the cant is estimated at roughly 3.8°, meaning the stock geometry needed a correction in the opposite direction to bring the barrels back into vertical alignment. That may sound small, but in shotgun fit it is large enough to change the sight picture and affect how the gun moves through vertical and angled target lines.

This is where the distinction matters again. The piston system addressed recoil. The custom stock geometry addressed fit. Lowering the comb and correcting cant were not recoil solutions; they were alignment and point-of-impact solutions. They changed where the gun shot for my natural mount.

From Measurements to a Digital Model

After the online fitting, Sai turned the measurements and observations into a digital model. That step gave the process a level of precision and confidence that I appreciated. The model incorporated the geometry needed for my mount, including the lowered comb, the correction for cant, and the shape needed to bring my head and hands into a more consistent position.

I reviewed and approved the digital model before the manufacturing process began in a second zoom call.

This approval step mattered. A custom stock can feel mysterious from the shooter’s side. You give someone measurements, trust their judgment, and wait for the result. Seeing the digital model made the process feel more concrete. The fitting session had become a design. The design would become the stock.

Building the Stock in Hayward

I then traveled to Hayward, California, in Silicon Valley, to pick up the stock, and get final adjustments based upon actual shooting. I, also, wanted to see Sai’s manufacturing process. The facility reflected what I had already begun to understand about the Grip+ system: it is part engineering, part craftsmanship, and part gun fitting.

The stock is not simply a shaped replacement part. It is a mechanical system built around a shooter’s body and mount.

Fine wood blanks at the Grip+ facility in Hayward, California, waiting to become custom shotgun stocks. The two finished stocks shown at the right illustrate the transformation from raw wood selection to personalized stock geometry, where appearance, fit, grip shape, comb position, and recoil-management design all come together in the final build.

Chuck Poon aligns a wood blank on the CNC machine. This step translates the approved digital stock design into precise cuts, shaping the blank toward the custom geometry needed for proper fit.

The stock and comb were manufactured to match the approved model. The comb was especially important because it carried the most direct correction to the gun’s point of impact. Lowering it by approximately one centimeter helped bring my eye into a more appropriate relationship with the rib. That change helped move the gun away from its high-shooting tendency and toward a sight picture that matched where the gun was actually pointed.

At the same time, the piston system was integrated into the stock to change recoil. This is the part of the system that later confused my ShotKam. It does not make the shotgun recoil-free. Instead, it changes the shape of the recoil impulse. The force is still there, but it feels less abrupt.

For a shooter, that can mean less fatigue, less face slap, reduced shoulder impact, and better recovery between shots. For pairs, that second-shot recovery is not just about comfort. It is about keeping the gun under control.

The Grip+ stock clamped during final fitting, with the piston-based recoil system visible behind the custom grip and adjustable comb. The piston changes how recoil is delivered to the shooter by spreading the force over a longer impulse, reducing the sharpness of the kick and helping the gun recover more smoothly between shots.

A Custom Finish

The manufacturing process also included a distinctive laser engraving step, but this was more than decoration. Sai has designed his own custom non-slip grip surface for the stock, and it is not the same as conventional checkering on a traditional gun stock. Instead of a uniform diamond pattern, the laser creates an irregular texture that is used consistently across his custom stocks. The pattern is not personalized to each individual shooter, but it is purpose-built to increase hand contact, improve control, and give the grip a more secure feel.

Visually, it was one of the most interesting parts of the build. The laser work gave the stock a finished, highly engineered quality and helped it feel less like an aftermarket component and more like a complete custom system. It also reflected the larger philosophy behind the Grip+ process: digital design, controlled manufacturing, hand fitting, functional grip texture, and precision finishing all coming together in a single custom stock.

Sai Chang stands beside the digital laser engraver at the Grip+ facility in Hayward, California. In addition to adding custom markings, the laser is used to create the textured, non-slip gripping surface on each custom stock.

Laser-engraved non-slip grip surface on the finished Grip+ stock. Unlike conventional checkering, Sai Chang’s irregular grip pattern is designed to increase hand contact and control while preserving the custom contours of the stock and maintaining a clean, integrated appearance.

Final Fitting on California Targets

The fitting did not end in the shop. That was another important part of the experience. A shotgun stock can look right on a bench and still need to prove itself on targets. Sai and I tested the stock in stages, beginning at Coyote Valley and then finishing the process at Birds Landing.

Coyote Valley was the first real test. This was where the stock began to move from measurement and machining into actual performance. Shooting real targets immediately showed things that static measurements could not fully capture: how the gun came up, whether the sight picture felt natural, whether the comb put my eye in the right place, and whether the reduced recoil helped with recovery. After that first shooting session, it was clear that the gun was much closer than before, but still shooting a bit high. Sai took the gun back to the shop and removed a small amount of additional material from the comb to fine-tune the point of impact.

That adjustment set up the second stage of the process at Birds Landing. By then, the stock had already been modified based on what we learned at Coyote Valley, so the Birds Landing session was less about identifying the major problem and more about confirming the final fit. There, we could evaluate whether the refined comb height produced the correct sight picture, whether the gun felt balanced and controllable on pairs, and whether the point of impact now matched my natural mount.

Those two sessions worked together. Coyote Valley revealed the final adjustment that was still needed; Birds Landing confirmed that the adjustment had moved the gun in the right direction. I strongly recommend that you take advantage of Sai’s expertise by going out for the final fitting. 

By the time I returned home, the stock was close to dialed in. But “close” is not the same as fully adapted.

After the first fitting session on live targets at Coyote Valley, the gun was still shooting slightly high. Sai Chang made a final comb adjustment by removing a small amount of material, fine-tuning the stock so the sight picture and point of impact would better match my natural mount.

Seeing the Difference with Shot Tracker

The Shot Tracker images helped confirm what I was feeling on the course. Before the fitting, the images showed the gun shooting high. After the Grip+ stock and additional practice, the images showed a much more centered relationship between the barrel, the target, and the point of impact.

This was useful because it separated feeling from evidence. I could feel that the gun was shooting differently, but the images helped document the change.

Shot Tracker comparison before and after the Grip+ stock fitting. With the factory stock, the shot pattern was biased high relative to the target center. After the Grip+ stock was fitted and the comb height was corrected, the pattern moved closer to the center, showing a better relationship between the barrel, target, and point of impact.

This is another place where the key theme matters. ShotKam revealed the recoil change. Shot Tracker helped document the point-of-impact change. One tool showed that the piston had altered the recoil signature. The other helped show that the custom geometry had corrected the way the gun shot for me.

Shot Tracker and Cloud Analysis

Shot Tracker and ClayTracker Cloud provide a different kind of feedback from ShotKam. ShotKam shows a video of the shooter’s view as the gun moves to the target. Shot Tracker, by contrast, is focused on analysis: it helps show where the gun is shooting relative to the target and whether the pattern is centered, high, low, ahead, or behind.

That makes it especially useful when evaluating gun fit. A shooter can often feel that something is off, but it is difficult to know whether the problem is the mount, the move, the sight picture, or the point of impact. Shot Tracker helps make those tendencies visible. By reviewing the data in ClayTracker Cloud, the shooter can look for patterns across multiple shots rather than relying on memory from a single target.

For my Grip+ stock fitting, this was important because I was trying to separate two different changes. Shot Tracker helped document the other major change: the custom stock geometry had changed point of impact.

Before the fitting, my Shot Tracker images showed that the gun was shooting high. That matched what the fitting process revealed: my comb needed to be lowered and the cant in the gun needed to be corrected. After the Grip+ stock was installed and I spent time practicing with the new sight picture, the Shot Tracker images showed a more centered relationship between the barrel, target, and point of impact.

ClayTracker Cloud made that comparison easier because it provided a visual record of the before-and-after results. Instead of simply saying the gun felt better or seemed to shoot flatter, I could look at the images and see the change. For a shooter adapting to a new stock, that feedback is valuable. It helps confirm whether the gun is actually shooting differently, and it also helps the shooter learn to trust the new sight picture.

Learning a New Sight Picture

When I got home, the real learning curve began. The gun no longer shot high, which was the goal. But my brain and eyes still remembered the old gun.

That is one of the most interesting parts of a major fit correction. A corrected gun may initially feel wrong because the shooter has spent so much time adapting to an incorrect fit.

With the old setup, I was used to a sight picture built around a gun that shot high. With the new stock, the gun shot closer to where it was pointed. That is better, but it required me to stop making old compensations. I had to learn to trust the new relationship between my eye, the rib, the barrel, and the target.

I worked through that adjustment with practice at Deer Creek Hunt Club in Michigan and Kosko Shotgun Sports in Indiana. These practice sessions were important because they gave me time to settle into the new FITASC mount. In FITASC, the gun begins out of the shoulder, so the stock has to come to the face consistently under movement rather than starting from a fully mounted position. FITASC places a premium on a controlled and repeatable mount. The gun has to come to the face and shoulder consistently, and the shooter has to trust the sight picture immediately. The Grip+ stock helped with that, but I still had to do my part.

Maintaining the Piston System

The piston system also adds a small but important maintenance routine. The Grip+ stock is not simply a shaped piece of wood; it is a mechanical recoil-management system, and the piston pressure matters. In my setup, the piston should be maintained at 65 psi. Shooters should follow Grip+ guidance on proper fill pressure for their own stock

The piston is filled through a Schrader valve, but there is one practical complication: the zero-leak fill system I use will not fit unless the butt plate is removed. That extra step is worthwhile because the air volume inside the piston is very small. With such a small volume, even a tiny amount of air loss while disconnecting a standard pump can drop the pressure below the desired setting.

That is why the zero-leak tool is useful. It reduces the amount of pressure lost when connecting and disconnecting from the valve. Without it, you have to be very quick and careful removing the filling pump, or the small burst of escaping air can lower the piston pressure enough to matter. It is a minor maintenance detail, but it is part of owning a stock that uses an active recoil-reduction system rather than a conventional fixed stock.

Filling the Grip+ piston through its Schrader valve using a no-leak fill system and a Ryobi cordless air pump. Because the piston volume is very small, even a brief loss of air while disconnecting a standard pump can drop the pressure below the desired setting. The no-leak Schrader valve tool helps prevent that pressure loss, but the butt plate must be removed to provide enough access for the fitting.

Competition: Testing the Stock Under Pressure

Eventually, the stock had to be tested in competition. Practice is one thing. Competition is another.

I used the gun in FITASC competitions at Northbrook Sports Club and at the FITASC North American Championship at Big Red Oak in Gay, Georgia. Those events gave me a much better sense of how the stock performed under pressure.

On the FITASC course at the 2026 North Central Regional at Northbrook Sports Club. After the Grip+ stock fitting, competition became the real test: learning to trust the corrected sight picture, manage the new point of impact, and let the gun do what it was finally fit to do.

Overall, the gun is now dialed in very well for my FITASC mount. The recoil is softer. The gun recovers well. The mount feels more repeatable. Most importantly, the gun now shoots much more honestly for me. I no longer feel as if I am managing a high-shooting gun. I feel as if I am learning to trust a gun that has been corrected.

That does not mean the adjustment is finished.

My biggest challenge now is teal-type targets. With the gun no longer shooting high, I often have to cover the target with the barrel. That is a difficult adjustment because it conflicts with the sight picture I had learned before.

When the gun shot high, I could see the bird above the barrel and let the pattern go higher than the barrel seemed to indicate. On teal targets, especially rising or dropping presentations where the vertical relationship is obvious, that old sight picture felt comfortable.

Now the gun is more honest. If the target needs to be covered, I have to cover it. That can feel visually uncomfortable because the barrel may briefly obscure the target. The old instinct is to float the barrel underneath the bird and trust the gun to shoot high. But that old instinct belongs to the old fit.

This has become the practical reminder that fitting a gun is not only a mechanical process. It is also a learning process. The Grip+ stock corrected the gun, but I still have to correct the shooter. Teal targets reveal that better than anything else. They show where old habits remain.

The Stock That Changed the Gun

Looking back, the most memorable moment remains that first practice session when my ShotKam missed every second shot. What seemed at first like a technology problem turned out to be evidence that the stock had changed the gun in a fundamental way.

The recoil impulse was softer. The ShotKam revealed this as it no longer recorded any second shots, because the accelerometer did not register the recoil signature of the first shot which it uses to determine the need to record a second shot.

But the more important change was not just recoil. It was fit. The piston system changed how the gun came back into my shoulder. The custom geometry changed where the gun shot for my natural mount. Those are separate improvements, and both were necessary.

The Grip+ stock did far more than make my Blaser F16 more comfortable. It fundamentally changed how the gun fit, pointed, recoiled, and performed. More importantly, it demonstrated that modern shotgun fitting can combine engineering, digital technology, and traditional craftsmanship into one integrated process.

Looking back, what impressed me most was not a single feature but the entire system. The digital fitting, CAD design, customer approval, precision CNC manufacturing, and final live-fire fitting all worked together toward one objective: building a shotgun stock that adapts to the shooter rather than forcing the shooter to adapt to the shotgun.

That philosophy may ultimately be Grip+’s greatest innovation. It is more than a custom stock; it is a digital bespoke shotgun stock manufacturing platform that creates and permanently preserves a shooter’s personal stock profile for future reproduction or refinement. As the shooter changes over time, the digital profile can evolve as well, making the relationship between shooter and shotgun a continuous process rather than a one-time fitting.

With the finished Grip+ stock installed on my Blaser F16, I stand with Sai Chang and Chuck Poon at the Grip+ facility in Hayward, California. Sai and Chuck fixed the gun fit, corrected the geometry, and delivered a stock that now shoots where I am looking. From here, the responsibility shifts back to the shooter: learning the new sight picture, trusting the corrected point of impact, and figuring it out on the course.

Jeff Terry is a researcher and academic leader whose work spans chemical physics, materials characterization, synchrotron radiation science, and research administration. He currently serves as Vice Provost for Research and Professor of Physics at the Illinois Institute of Technology, where he leads university-wide efforts to strengthen research infrastructure, expand strategic partnerships, support faculty scholarship, and grow Illinois Tech’s national research profile. He is an avid sporting clay shooter and can often be found at large shoots across the United States. 

Valuable resources:

The Grip+ web site

Jeff Terry

Jeff Terry is a researcher and academic leader whose work spans chemical physics, materials characterization, synchrotron radiation science, and research administration. He currently serves as Vice Provost for Research and Professor of Physics at the Illinois Institute of Technology, where he leads university-wide efforts to strengthen research infrastructure, expand strategic partnerships, support faculty scholarship, and grow Illinois Tech’s national research profile. He is an avid sporting clay shooter and can often be found at large shoots across the United States.