Burris FastFire® C — Micro Red Dot Reflex Sight

Item #: 300239 | Dot size: 6 MOA | Battery: 1× CR2032 (bottom-load)

Tech Notes — Astigmatism, Blurry Dots & Setup Tips
• Astigmatism: Uncorrected astigmatism or dry eyes can make the dot look like a starburst/comet. Check by viewing the dot through a phone camera (should look crisp), and/or lower brightness.
• Training (handguns): Bring the sight close to your eye to acquire the dot, then press out slowly while keeping it centered; repeat until presentation is automatic.
• Mounting gotcha: If you see a tiny emitter glow low in the field of view but no dot on the window, the sight is likely mounted backward—flip it.
• Emitter cleanliness: Smudges, oil, or dust on the small emitter lens can blur/flare the dot. Blow off dust, use a soft lens brush, then (only if needed) a tiny amount of lens cleaner on microfiber. Avoid harsh solvents; do not touch the LED.

1) Itemized Components (Product Map)

Item #	Component	What it does
1	Power / Brightness Button (left)	Cycles manual levels; long-press to power Off; also supports Auto mode.
2	Brightness Sensor (front)	Drives Intelligent Auto-Bright; keep unobstructed/clean.
3	Elevation Screw (top)	POI vertical adjust; 4 MOA per tick mark; 80 MOA total.
4	Windage Screw (right)	POI horizontal adjust; 4 MOA per tick mark; 80 MOA total.
5	Sight Window / Lens	22 × 17 mm window; parallax-free; true 1× use.
6	Bottom Battery Tray (CR2032)	Install with “+” down; secured when optic is mounted.
7	Removable Rear Post Sight (optional)	Optional rear post to co-witness with the pistol’s front sight.

2) Package Contents & Mounting Footprint

Included	Footprint / Hardware
FastFire C sight; removable rear post sight; 60 MOA (1°) shim; Screw sets: (4) M4×0.7 6.5 mm, (4) M4×0.7 7.0 mm, (4) M3×0.5 7.5 mm, (4) 6-32 8.2 mm; Sight adjustment / mounting tool; 1× CR2032 battery; lens cloth; user guide.	Shield RMSc™ footprint. If your slide isn’t RMSc, use a compatible third-party adapter plate. Torque: mounting screws ≈ 9 in-lb.

3) Pistol Compatibility — Screw Lengths (No Shim vs With Shim)

Pistol Model	No Shim	With Shim
Springfield Hellcat	M4×0.7 6.5 mm	M4×0.7 7.0 mm
SIG Sauer P365	M3×0.5 7.5 mm	M3×0.5 7.5 mm
S&W Shield Plus	6-32 8.2 mm	6-32 8.2 mm
Ruger Max-9	M4×0.7 7.0 mm	M4×0.7 7.0 mm
Glock 43/43X/48 MOS	M4×0.7 6.5 mm	M4×0.7 7.0 mm
CZ P-10 S	M4×0.7 7.0 mm	M4×0.7 7.0 mm
Stoeger STR-9	M4×0.7 6.5 mm	M4×0.7 7.0 mm
Beretta 80X Cheetah	M4×0.7 6.5 mm	M4×0.7 7.0 mm

4) Shim & Rear Post Notes

60 MOA shim: Thick edge forward = more up elevation; thick edge rear = more down elevation. (60 MOA ≈ 60″@100 yds, 30″@50 yds, 15″@25 yds.)
Rear post sight: Installs/removes using the same mounting screws; intended to co-witness with the pistol’s front sight.

5) Power, Brightness & Auto

Manual levels: 5 brightness settings (#1 High → #5 Low) plus Auto (Intelligent Auto-Bright).
Auto behavior: When holstered/stored, the dot drops to ultra-low to save power; after ~5 hours, any manual setting defaults back to Auto.
On/Off: Short-press to cycle brightness; long-press to power Off.
Battery life: ~25,000 hours on Medium.

6) Zeroing

Adjusters: Use the included tool or a small flathead screwdriver. Each tick mark ≈ 4 MOA.
Travel: Elevation 80 MOA; Windage 80 MOA.
Direction: Elevation—Right = Up / Left = Down. Windage—Right = Right / Left = Left.

7) Environmental & Care

Water-resistant IPX44; after exposure to salty/dirty water, rinse with distilled water and dry.
Clean optics with blower/soft brush first; then lens tissue/solution if needed.

8) Quick Specs (Reference)

Spec	Value
Magnification	1× (parallax-free, both-eyes-open)
Window	22 × 17 mm (0.87″ × 0.67″)
Reticle	6 MOA red dot
Adjustment Range	Elevation 80 MOA / Windage 80 MOA
Adjustment Graduation	4 MOA per tick mark
Operating / Storage Temp	−4 °F to +140 °F / −22 °F to +140 °F
Power Supply	1× CR2032 (bottom-load)
Dimensions (L × W × H)	1.61″ × 0.99″ × 0.98″ (40.8 × 25.1 × 24.9 mm)
Weight (optic only)	~0.44 oz (12.5 g)

User Guide (PDF): FastFire C User Guide — INSTR-9239

Related to