Primary Arms SLx 3x MicroPrism - ACSS Raptor 5.56/.308

The Primary Arms SLx 3x MicroPrism gives you a 3x magnified optic in a package the size and weight of a red dot. It combines the compact footprint of a microdot, under 8 ounces, with the durability and precision of a prism scope, and it's the answer for a lot of shooters who want more than a 1x dot without hanging a full-size optic off their rifle. It won a 2022 Industry Choice Award for red dot of the year and carries an NTOA silver-tier rating, so it's not a cheap-out, it's a legitimately good optic at an approachable price.

The reason to choose a prism over a red dot comes down to two things. First, the reticle is etched into the glass, so it's always there whether the illumination is on or not, if the battery dies, you still have a fully usable black reticle. Second, and this is the big one for a lot of people: a prism works for shooters with astigmatism. If a red dot looks like a smeared starburst to you, that's astigmatism interacting with the LED, and a prism's etched reticle solves it completely. It shows up crisp and clean. For many buyers, that's the entire reason they're here.

What makes this one special is the ACSS Raptor reticle, calibrated for 5.56 and .308 in yards. It's not just a dot, it's a complete ranging and holdover system. The chevron tip gives you a precise aiming point, and built into the reticle are bullet-drop compensation holds out to distance, auto-ranging brackets to estimate range on a man-sized target, wind holds, and moving-target leads. In practice you range, hold, and press without dialing anything. It's a point-and-shoot system for a fighting rifle where speed matters more than sub-MOA precision.

It runs 13 brightness settings with AutoLive motion-sensing, the illumination shuts off when the optic sits still and snaps back on the instant you move the rifle, so it's effectively always ready and the battery lasts. It's night-vision compatible, comes with a mount, and we carry it in black and FDE. Browse the rest of our optics and scopes here.

3x MicroPrism or 5x MicroPrism?

We carry both. This 3x is the faster, closer-range option, ideal from CQB distances out to a few hundred yards, with the auto-ranging ACSS Raptor reticle built for quick holdovers on a fighting rifle. The 5x MicroPrism reaches further for mid-range work and uses the ACSS Aurora MIL reticle for more deliberate, precision-style shooting in mils. Get the 3x for speed and a do-it-for-you BDC; get the 5x for reach and precision holds.

Prism vs Red Dot + Magnifier

If you're deciding between a prism and a red dot with a flip-to-side magnifier, here's the honest trade. The prism is one sealed unit, lighter and simpler, with a detailed etched reticle and no moving parts, and it works with astigmatism. A red dot plus magnifier like the Holosun HM3X behind an ARO lets you flip the magnifier away for a true 1x, which the fixed 3x prism can't do. If you want a genuine 1x option for close range, go red dot plus magnifier. If you want a lighter, simpler unit with a richer reticle and astigmatism compatibility, the prism wins.

Key Features

• 3x magnification, red-dot size. Under 8 oz, smaller and lighter than many red dots.
• Etched ACSS Raptor reticle. Works illuminated or not; caliber-calibrated for 5.56/.308.
• Astigmatism friendly. Etched reticle stays crisp where a red dot smears.
• Auto-ranging BDC. Range estimation, holdovers, wind, and moving-target leads built in.
• AutoLive motion sensing. 13 brightness settings, illumination wakes on movement.
• Award-winning. 2022 ICA red dot of the year, NTOA silver-tier rated.
• Mount included. Night vision compatible. Black or FDE.

Specs

• Type: Fixed 3x prism scope
• Reticle: Red illuminated ACSS Raptor, etched, calibrated 5.56/.308 (yards)
• Magnification: 3x
• Illumination: 13 settings with AutoLive motion sensing
• Night vision: Compatible
• Weight: Under 8 oz
• Mount: Included
• Colors: Black or FDE
• Recognition: 2022 ICA Red Dot of the Year, NTOA Silver-tier

FAQ

Will this work if I have astigmatism?
Yes, and it's one of the main reasons to choose a prism. A red dot's LED can look like a smear or starburst to shooters with astigmatism. This optic uses an etched glass reticle, so it stays crisp and clean regardless. If red dots have never looked right to you, a prism is the fix.

What is the ACSS Raptor reticle?
It's a calibrated aiming system for 5.56 and .308. Beyond the chevron aiming point, it includes bullet-drop holdovers, auto-ranging brackets to estimate distance, wind holds, and moving-target leads, all etched into the glass. You range, hold, and shoot without dialing.

Does the reticle work if the battery dies?
Yes. The reticle is etched into the prism, so it's always visible as a black reticle even with the illumination off. The battery only powers the red illumination, not the reticle itself.

Should I get the 3x or the 5x?
Get the 3x for faster, closer shooting out to a few hundred yards with an auto-ranging BDC reticle. Get the 5x for more reach and precision-style holds in mils. The 3x leans fighting rifle; the 5x leans mid-range precision.

How's the battery life?
Long, thanks to AutoLive. The illumination sleeps when the optic is still and wakes the instant you move the rifle, so it's always ready without draining the battery. And even off, the etched reticle remains usable.