Best Optics for a Straight-Pull AR

For most straight-pull AR shooters, the best single optic is a 1-6x or 1-8x LPVO. It works like a red dot at 1x and gives you magnification for scoring or identifying targets further out. The SIG Sauer TANGO-MSR 1-6x24 is the easiest start, because it comes with its own cantilever mount. If your shooting is all close, timed stages, a 1x red dot such as the Holosun HS510C is faster. If you have astigmatism, or want an optic that still works with a flat battery, a prism such as the Primary Arms SLx 3X MicroPrism is the better answer.

The straight-pull AR is the AR-15 platform as Great Britain has it: the same ergonomics, handguard and rail, but cycled by hand with a lever or handle instead of by gas. It is widely used in practical rifle and club shooting, and people come to it from stalking, from clays and from nothing at all. That is why "what optic goes on it" gets such different answers. Everything named here is in our straight-pull rifle optics collection.

Start with the course of fire, not the optic

• Timed practical stages, close targets, movement: a 1x optic, either a red dot or a 1x prism. Speed is everything and magnification gets in the way.
• Deliberate fire at 100 to 300 m and beyond: an LPVO, or a fixed prism at 3x to 5x. You need to see the target to score it.
• Both, on the same rifle, on the same day: an LPVO with a genuine 1x, or a magnified optic with an offset red dot alongside it.

LPVO, prism or red dot

The LPVO case

A low-power variable optic behaves much like a red dot at 1x with the illumination on, then winds up when you need to look at something properly. It is the most versatile single optic on this platform. Our explainer what is an LPVO covers the basics.

The SIG Sauer TANGO-MSR 1-6x24 with the illuminated MSR BDC6 reticle is the straightforward version, and the one we point most people at first, because of what's in the box. You get a 30 mm tube scope and an ALPHA-MSR one-piece cantilever mount, so there are no rings to buy. SIG lists it at 10.4 in long and 18.5 oz, running on a CR2032 (SIG Sauer TANGO-MSR 1-6x24). The 1-8x24 and 1-10x28 reach further. The TANGO-MSR Compact 1-6x24 is 8.4 in long if rail space is tight (SIG Sauer).

For a first focal plane reticle whose subtensions stay true at every magnification, look at the EOTech Vudu 1-6x24 FFP with the SR3 MOA 5.56 BDC reticle or the Vudu 1-10x28 FFP. For value with a well-thought-out reticle, there's the Primary Arms SLx 1-6x24 Gen IV with the red illuminated ACSS Nova Fiber Wire reticle. Or step up to the PLxC 1-8x24 FFP with the ACSS Raptor 5.56/.308 Yard G2 reticle. Our best LPVO rifle scopes guide compares the magnification bands.

The prism case

A prism scope has fixed magnification and a reticle etched into the glass. That buys two things a red dot can't offer. It still works with the battery flat, and it stays sharp for shooters with astigmatism, who often see a projected dot as a smear, flare or double image.

The Primary Arms SLx 3X MicroPrism with the ACSS Raptor 5.56/.308 Yard reticle is the sweet spot for this platform. Primary Arms lists it at 2.95 in (75 mm) long and under 7.95 oz (225 g), with 1/4 MOA clicks and 80 MOA of total elevation and windage travel. Its field of view is 38 ft at 100 yd, about 12.7 m at 100 m, and the CR2032 gives up to 29,000 hours on a medium setting. It ships with a mount offering eight height and position configurations, so the mounting problem is solved in the box (Primary Arms). If you want more reach, there is also the SLx 5X MicroPrism.

At 1x, the SLx 1X MicroPrismT with the ACSS Cyclops Gen II reticle is 2.48 in (63 mm) and 5.5 oz (156 g). It sits on the H1/T1 micro-dot footprint with a 2.26 in mount included, making it a prism genuinely the size of a micro dot. See prism scopes explained.

The red dot case

For stages measured in seconds, a 1x dot is still the fastest thing there is. The Holosun HS510C brings the Multi-Reticle System (2 MOA dot, 65 MOA circle, or both) and an integrated quick-detach Picatinny mount at 1.41 in (35.8 mm) (Holosun HS510C). If you shoot in all weathers, the enclosed Holosun AEMS EVO offers the same reticle system with a sealed emitter.

To keep the dot's speed but add reach, a flip-to-side magnifier is the usual answer. Options include the Holosun HM3X 3x, the EOTech G43 3x with STS mount or the SIG Sauer JULIET3 Micro 3x. Our choosing a red dot magnifier guide covers 3x against 5x and 6x.

Trijicon's ACOG, whose fibre-optic and tritium lighting needs no battery at all, is a classic choice on this platform, but we don't currently stock it or the Trijicon MRO.

Mount height, and why it is not a detail

An AR-pattern rifle has a straight stock with the comb high relative to the bore, so an optic at bolt-action height puts your cheek nowhere useful. The standard heights exist for that reason:

• Absolute co-witness, about 1.41 in (35.8 mm): the height of the HS510C's integrated mount.
• Lower 1/3 co-witness: iron sights sit in the bottom third of the window, giving a cleaner view.
• Raised, 1.93 in and 2.26 in: a more upright head position, easier in a heavy coat, and increasingly common. The SLx 1X MicroPrismT ships with a 2.26 in mount.

Our red dot mount height chart gives the full picture, co-witness heights included. For a tube scope, you want a cantilever mount: its rings sit forward of the clamp, so the scope can go far enough back on a receiver-length rail for correct eye relief. The TANGO-MSR's ALPHA-MSR mount is one. We don't currently stock separate cantilever scope mounts, so if your LPVO comes without a mount, source one separately.

Frequently asked questions

Is an LPVO or a red dot better on a straight-pull AR?

An LPVO if you shoot at varied distances or need to identify targets; a red dot if your shooting is close, fast and timed. An LPVO at 1x with the illumination on gets close to red dot speed, at the cost of weight and a less forgiving eye box.

What magnification LPVO should I buy?

1-6x is the classic and the lightest. 1-8x is a good balance of reach against weight. 1-10x gives the most reach and pays for it in length and a smaller exit pupil at the top end.

Why choose a prism over a red dot?

Astigmatism and battery independence. A prism's reticle is etched into the glass and focused by the optic's own eyepiece, so it stays sharp where an LED dot smears, and it still works with the cell flat.

Can I run an offset dot alongside a scope?

Yes, and it's common on this platform. A 45-degree offset red dot gives you a close-range option without giving up the magnified optic.