In this DonnyFL Field Notes blog, we’re diving into a recent conversation I had with Thayne Simmons from Team Saber Tactical about his newest FX Impact M4 build—a purpose-built setup fully decked out with all the latest 2025 Saber Tactical gear. Thayne walked me through every component he added to his rifle and explained why each one plays a critical role in his success as a precision shooter, whether he’s competing in PRS-style matches or hunting in the backcountry.
This isn’t just a showpiece build. This is the real-world setup of a shooter who demands performance, repeatability, and adaptability under all conditions. The gear we’re covering here paried with the FX Impact M4 has been tested, tuned, and trusted—each piece selected for a reason.
Let’s take a closer look at what went into this FX M4 build and why it matters.
TRS Rail: Structural Integrity with Built-In Long-Range Utility
The redesigned TRS (Top Rail Support) Rail is arguably the most function-forward piece of the 2025 lineup. This full-length, monolithic top rail does two things exceptionally well: it reinforces the barrel system to eliminate flex and shifting under load, and it delivers a built-in 20 MOA cant to extend the range capability of your optic.
That structural rigidity provided by the integrated barrel support is not just theoretical. On long-barreled FX Impacts—especially in heavy calibers or with larger scopes—the TRS prevents harmonics from introducing point-of-impact shifts during transport, tripod use, or even aggressive positional shooting.
During our testing, we ensured this built-in device didn't negatively affect harmonics as there is a misconception that the FX Impact is a truly free-floated barrel. It is not. There are multiple points the barrel is supported already within the stock barrel system as it feeds through the cocking area of the platform. The TRS rail just adds one more point that helps especially when running 700mm and 800mm barrel systems. The TRS system eliminates barrel droop and gets rid of that problem at the source.
The integrated bubble level helps eliminate cant, ensuring your rifle remains level during shot execution. In both PRS stages and hunting scenarios at extended distances, avoiding cant error is critical to maintaining horizontal POI alignment and consistent wind hold performance. It's not just a rail—it’s a structural backbone for the rifle.
Low Profile Bottom Rail: Tripod Optimization Done Right
Underneath the FX Impact M4 air rifle, the Low Profile Bottom Rail offers a slimmer, skeletonized mounting solution for shooters who operate off tripods and bipods or require modularity. Designed to interface cleanly with Arca-Swiss and Picatinny tripod heads or bipods, this rail gives you direct, locked-in mounting without excessive height or unwanted bulk.
Thayne emphasized how critical this component is when he's hunting or transitioning between stages in a competition. By lowering the rifle’s overall height, the rail drastically improves maneuverability. M-LOK slots provide room for additional weights or accessories, letting shooters fine-tune their system based on balance point and application.
If you run a tripod in the field or in a match setting, this is an essential component that does exactly what it's supposed to: keeps the rifle steady and maneuverable.
Skeletonized Grip: Ergonomics Meets Tactical Efficiency
Saber Tactical’s Skeletonized Grip isn’t just about shedding weight—it’s about optimizing the shooter’s connection to the rifle with the perfect ergonomic angle. The contoured profile offers improved finger indexing, and the extended thumb shelf supports a relaxed, repeatable hand position whether you’re pressing through a slow benchrest trigger or managing recoil in semi-auto mode. This grip is a more traditional AR style angled design which some shooters still prefer, but Saber Tactical also overs zero degree angled grips as well.
Thayne pointed out how this grip gives him consistent contact and reduced strain during long shooting sessions and different shooting positions. For PRS competitors, it reduces hand fatigue when transitioning through stages. For hunters, it provides consistent control, even when gloves are on or the weather turns wet. The skeletonized cutouts keep it lightweight without compromising rigidity.
New Adjustable Buttstock with Integrated Bag Rider: Built for Real Shooting Positions
The updated buttstock and integrated bag rider are designed from the ground up to accommodate the realities of precision shooting in all its forms. First, the tool-less adjustability of both cheek riser height and length of pull makes fine-tuning the fit of the rifle fast and intuitive. Whether you're shooting prone off a rear bag, seated at a match, or standing off a tripod in the field, this stock adapts to your position, not the other way around.
Where this buttstock shines, though, is in the rear interface. The flat-bottomed bag rider is CNC-machined for precise glide under recoil and works perfectly with rear bags in benchrest or PRS-style stages. It’s not just a passive contact point—it’s an active support tool that tracks consistently during recoil, improving follow-through and reducing shot-to-shot deviation.
The silicone buttpad offers aggressive shoulder grip, especially when shooting without a rear bag. This is critical for field hunters or speed match competitors where rear support isn’t allowed. Thayne mentioned how he sets the buttstock at its steepest angle during fast-moving stages—driving it into his shoulder for fast target acquisition and control under pressure.
DonnyFL Yokozuna Suppressor: Powerhouse Silence with Precision
At the end of the barrel, the Yokozuna from DonnyFL isn’t your average suppressor. This full-size, high-volume unit is built with the needs of high-power shooters in mind—especially those running hot-rodded .22 or .25 cal rigs and really shines up through .30 and .35 caliber platforms.
What sets the Yokozuna apart is its ability to reduce shot report without sacrificing accuracy and is modular to harmonically tune your airgun. Thayne stressed the importance of staying quiet in the field but also noted that on the bench or in a match, having a suppressor that doesn’t disrupt barrel harmonics or point of impact is just as important. Add to that its modular, tunable design, and you’ve got a suppressor that performs at the highest levels across a wide range of calibers and power settings while serving as a dual-purpose tuning device.
Proven in the Field and Competition: Thayne is a Trusted Source of Info
Every time I talk gear with Thayne, I make it a point to listen. The fact that he’s a proven airgun competition champion definitely carries weight—but I’ve also hunted with him many time out in Utah, seen him in action in tough field conditions, and watched him execute clean shots under pressure. He doesn’t miss. That’s why when he walks me through a build like this, I take notes. Because when someone like Thayne says this gear makes a difference, you can count on it delivering when it matters most.
