Primary Arms SLx MD25 Red Dot Sight Review

Let's face it—the red dot sight market is packed with options that all start to blur together after a while.

But the Primary Arms MD25 with ACSS (Advanced Combined Sighting System) reticle actually manages to stand out from the crowd. I've put together this guide to help you figure out if this optic deserves a spot on your rail.

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PA MD25 Red Dot Basic Specifications

Optic Type: Red dot sight with ACSS CQB reticle

Tube Size: 25mm objective lens (hence the "25" in MD25—mind blown, right?)

Weight: Approximately 6.4 oz (181.4g) — not exactly featherweight, but not a brick either

Length: 2.5 inches (63.5mm)

Battery Type: CR2032 (those little coin batteries you can find everywhere)

Battery Life: Up to 50,000 hours on medium settings (yes, that's over 5 years!)

Brightness Settings: 11 illumination settings (2 night vision compatible for you NVG enthusiasts)

Construction: 6061-T6 aluminum housing (the same stuff they build aircraft parts from)

Waterproof Rating: IP67 (submersible up to 1 meter for 30 minutes—though I wouldn't recommend using it as a diving accessory)

Mount: Low profile mount compatible with standard Micro footprint

Reticle: ACSS CQB reticle with bullet drop compensation or 2 MOA dot (Sold separately)

Warranty: Lifetime warranty (always a good sign when a company stands behind their product)

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The ACSS Reticle Advantage

If you're used to basic red dots with nothing but a simple dot, the ACSS reticle will feel like upgrading from a flip phone to a smartphone. The system includes:

Center chevron for precise aiming
Bullet drop compensation markings (because gravity is still a thing)
Range estimation tools
Moving target leads (for when those pesky targets won't stay still)
Auto-ranging capability
Wind holds