T&E Briefing: 6mm ARC Precision Night Hunting Build
Rifle Build Breakdown
This season, I’ve put together a custom AR-platform rifle centered around precision, suppressed night hunting with thermal optics. Here’s the full breakdown of the rifle’s components:
Barrel: Sons of Liberty Gun Works 13.9" 6mm ARC Precision Series SPR Barrel
Bolt Carrier Group: JP Enterprises 6.5 Grendel Bolt/BCM BCG
Trigger: Geissele Super Dynamic 3-Gun (SD-3G)
Upper Receiver: Bravo Company Manufacturing (BCM) Stripped Upper
Lower Receiver: Aero Precision M4E1
Buffer System: Forward Controls Design A5-Length Receiver Extension, Sprinco Green Spring, A5H1 Buffer
Gas Block: Odin Works Tuneable Adjustable Gas Block
Rail: Geissele MK8 13.5" (Freefloat M-LOK)
Suppressor: Yankee Hill Machine (YHM) Resonator K – direct thread adapter installed
Optic: Rix Leap L3 Thermal Scope
Furniture & Other: Mil-spec small parts, BCM Grip, Magpul MOE SL-K
Why This Build?
After a season of hunting with a 22" Ruger American Predator chambered in 6mm ARC, I was impressed by the cartridge’s flat trajectory and terminal performance. My handloads using 80gr Hornady ELD-VT over Leverevolution powder (in Hornady brass, with CCI 450 primers) yielded ~3150 FPS — absolutely devastating on everything from varmints to large boars.
However, the 22” bolt gun, with a suppressor, proved too unwieldy in a side-by-side. After dozens of climbs in and out per night, I knew I needed something more compact and nimble — hence the move to an AR platform. The trade-off? Sacrificing a bit of velocity for mobility and quick follow-up capability. My goal with this 13.9" barrel is to hit 2700–2800 FPS with a new load using the same ELD-VT projectiles, maintaining high BC performance with better handling.
Initial Impressions
Trigger – Geissele SD-3G
The SD-3G is incredibly smooth, with a rolling break and almost no wall. It's lightning-fast — ideal for fast follow-ups, which is crucial for predator hunting. That said, for slow, deliberate precision work, I personally prefer a trigger with a bit more wall. Depending on how it performs in the field, this trigger may find its way into a different style rifle.
Geissele Super Dynamic 3 Gun Trigger
Barrel – Sons of Liberty Gun Works 13.9" SPR
This barrel exudes quality. The bore and chamber are clean and well-machined, with a tight barrel extension fit. I had to heat the BCM upper to seat it properly — a testament to the thermal fit design. The pre-dimpled gas block journal is a nice touch for alignment. Be aware: it’s a heavy-profile barrel. Definitely not a lightweight hunting setup, but if you’re building a precision rig capable of maintaining accuracy under heat, this is the kind of profile you want.
Note: With a 13.5" handguard and 13.9" barrel, suppressor clearance is tight. I had to add extra shims to the direct-thread adapter to prevent the suppressor from touching the rail. For sub-14.5" barrels, I’d recommend going with a shorter handguard.
Bolt – JP Enterprises 6.5 Grendel
High-quality machine work as expected from JP. Time and round count will tell the full story, but so far, no complaints. Mated cleanly with the barrel extension and appears to lock up consistently.
Buffer System – A5 Setup
The combination of the Forward Controls Design A5 receiver extension, Sprinco Green spring, and A5H1 buffer has worked well for me in the past. I’m optimistic this will help tame the 6mm ARC, especially with the slower-burning Leverevolution powder and suppressor-induced backpressure.
Gas Block – Odin Works Tuneable
This block is a carryover from a previous build. Ironically, I never actually tuned it, so this will be the first time I really evaluate its adjustability. I may eventually compare it to something like the Superlative Arms block depending on how tuning goes.
Optics & Accessories
Thermal Scope – Rix Leap L3
I ran the Leap L3 all last season and was seriously impressed — especially for a 384-resolution optic. The ocular "zoom" feature (really just a zoom of the display screen via the ocular lens) is incredibly useful. It provides far greater clarity than digital zoom, and with the integrated throw lever, it’s fast and intuitive. One gripe: the battery door. It’s a bit finicky, and I’ve had occasional shutdowns after bumps. Hoping that gets sorted with different batteries or maybe a small mod.
Suppressor – YHM Resonator K
My first suppressor — and a solid budget pick. Sub-$500, HUB-compatible, and no frills. It's not titanium, but the weight and profile are manageable. It just works, and that’s really all I can ask.
Final Thoughts (So Far)
This rifle is purpose-built for night-time predator hunting: compact, accurate, and tuned for suppressed thermal work. While still early in the testing phase, fit and finish have impressed across the board. The key performance tests still lie ahead — gas tuning, load development, and real-world field time under thermal and suppression. I’ll post a follow-up T&E once field use begins in earnest.
If you're building a precision AR in 6mm ARC for hunting, and you're willing to accept a bit more weight for accuracy, this setup is shaping up to be a serious contender.
Coming Soon:
Load development results for the 80gr ELD-VT in this 13.9" barrel
Gas tuning results with the Odin Works block
Final velocity numbers with chrono data
Field performance under thermal at night
This post was made July 24, 2025 and will be updated below with field results as they become available.
