A red dot sight lets you keep both eyes on the target and put a single aiming point where you want the shot to go. It is faster than lining up front and rear sights, it helps shooters whose eyes struggle to focus on a front sight, and it is now standard on many carry and duty pistols. Here is how to choose one that fits your gun and the way you use it.
Is your pistol optics-ready?
Start with your slide. Most new pistols come “optics-ready,” with a cut in the top of the slide and a cover plate. Glock calls these models MOS, Smith & Wesson uses CORE and OR, and other makers use names like Optics Ready or RX. If your slide has no cut, you can still add a dot with a rear-sight dovetail plate or have a gunsmith mill the slide, but an optics-ready pistol is the simplest path.
Match the footprint
The footprint is the screw and post pattern under the optic, and it must match your slide or mounting plate. The three you will see most often:
- RMR: the full-size pattern from the Trijicon RMR, also used by optics like the Holosun 407C and 507C. Common on full-size and compact pistols.
- Shield RMSc: a narrower pattern for slim carry pistols like the Sig P365, Springfield Hellcat, Glock 43X and 48 MOS and many micro-compacts. Holosun’s 407K and 507K use it.
- ACRO: a newer pattern used by enclosed optics like the Aimpoint ACRO. Usually needs its own plate.
Optics-ready pistols that come with several plates, like Glock MOS models, can take more than one footprint. Check your pistol’s plate or cut and the optic’s listing before you buy, and pick up a red dot mount or plate if you need one.
Open or closed emitter
Most pistol dots are open-emitter: the LED sits exposed in front of the window. They are smaller and lighter, but rain, lint or mud can block the emitter. Closed-emitter dots seal the LED inside a housing, which many carriers and duty users prefer. They are a little bigger and heavier.
Dot size and reticle
Dot size is measured in MOA. A 2 to 3.5 MOA dot is precise for longer shots, while a 6 MOA dot is quicker to find up close. Many Holosun models offer a multi-reticle system that switches between a dot, a circle or both. If you are new to red dots, a circle-dot reticle can make the dot easier to pick up while you learn.
Battery life and controls
Look for long battery life and an auto-on feature. Holosun’s Shake Awake turns the dot on when the gun moves, and some models add a solar panel as a backup. Battery location matters too: a side- or top-loading battery lets you change it without removing the optic, while a battery under the optic means re-mounting and re-checking your zero.
Backup iron sights
Taller “suppressor-height” iron sights can co-witness through the optic window, so you still have sights if the dot ever fails, and they help you find the dot faster. Browse pistol sights, including Trijicon night sights.
Mounting and zeroing
Use the correct screws for your slide and plate. Screws that are too long can bind the slide or reach the firing pin channel. Torque them to the maker’s spec, use a small amount of blue threadlocker if recommended, and check them after your first range trip. Most shooters zero a carry pistol dot at 10 to 25 yards. If you carry, make sure your holster is cut for an optic.
Popular pistol red dots
- Holosun: the 407K and 507K for slim carry pistols, the 407C, 507C and 508T for full-size and compact pistols, and enclosed EPS models.
- Trijicon: the RMR, built for hard use, and the SRO, with a larger window for competition and the range.
- Other trusted names include Sig Sauer ROMEO, Leupold DeltaPoint Pro and Aimpoint.
Buying a pistol red dot online
Shop all red dot sights, or start with a pistol that is ready for one: our 9mm handguns include many optics-ready models from Glock, Sig Sauer and more. Red dots, mounts and sights are not firearms, so they ship straight to your door. Need holsters and parts for your model? See Glock 43X and 48 holsters, Sig P365 holsters and Hellcat holsters, and read our guide to choosing a 9mm carry pistol.
This guide is general information, not legal advice. Federal, state and local laws change and vary by location; check the current laws where you live before you buy, ship or carry.
