Extar EP9 Upgrades & Accessories: Complete Guide

The Extar EP9 has developed a near-cult following since its release and for good reason. At $469 it undercuts every other PCC on the market by hundreds of dollars while delivering reliability that punches well above its price tag. The secret is glass-reinforced polymer construction that brings the unloaded weight down to 4.09 lbs lighter than most loaded handguns.

Glock G17 magazine compatibility is the EP9's killer feature. It runs OEM Glock magazines, Magpul PMAG GL9, Extar's own EM9 18-round mags, ETS, KCI, and 33-round Glock sticks without modification. The patented last-round-hold-open works with Extar's own and most Glock-pattern magazines a feature many budget PCCs get wrong.

The lower receiver accepts standard AR-15 mil-spec trigger groups, which opens the entire AR aftermarket for upgrades. The 6.5-inch barrel is threaded 1/2x28 for suppressors, and the M-LOK handguard has 9 slots plus a full-length Picatinny top rail. The BLACKNITRIDE+ treated bolt, barrel, and ejector resist corrosion and wear well above the price point.

The biggest compromises are the polymer construction which lacks the premium feel of aluminum PCCs like the CMMG Banshee or SIG MPX, the mil-spec trigger that is functional but rough, and the complete absence of iron sights. You will need to budget for a red dot. The direct-blowback action is also snappier than roller-delayed or gas-operated designs seen on higher-end PCCs like the CMMG Banshee and SIG MPX.

The Extar EP9 runs remarkably well out of the box but one component deserves immediate attention. The factory polymer buffer retainer can shear under heavy use, leading to failure-to-feed issues. Extar addressed this on current production by switching to a steel 90-degree design, but earlier guns still ship with the plastic part.

The 90-Degree Buffer Retainer is a drop-in replacement that takes five minutes to install. At $35 it is the cheapest insurance against the EP9's most common failure point. After the retainer, the next essential upgrade is a quality red dot sight since the EP9 ships without any iron sights.

The EP9's polymer construction makes it exceptionally light, but the factory charging handle and brace leave room for improvement. Start with the extended charging handle ($27) which prevents your knuckles from contacting the optic mount during charging. For those building a dedicated defensive gun, a PDW-style or compact PCC setup is a natural direction for the EP9.

The EP Adjustable Receiver Extension ($50) converts the fixed brace to a six-position adjustable setup that accepts standard AR-15 Mil-Spec stocks and braces. Pair it with an SBA3 brace for the most popular pistol brace configuration on the market. Extar also sells the EP M-LOK Handguard ($45) and Blast Director ($25) as direct-fit OEM accessories from their site.

Because the EP9 accepts standard AR-15 mil-spec trigger groups, you have hundreds of aftermarket options. But the simplest path is Extar's own factory FCGs which are drop-in guaranteed with the EP9's polymer lower and include all necessary pins, springs, and the metal tuning plate. For shooters looking for a deeper dive into AR-pattern trigger selection, the same mil-spec FCG standard applies.

The Flat Nickel Teflon Steel FCG ($50) is a single-stage trigger with a smooth break and flat shoe that improves finger placement over the curved OEM trigger. The Flat Two Stage Nickel Boron Trigger Group ($100) adds a distinct wall and lighter break for shooters who want precision. Both are AR-15 compatible and will work in any mil-spec lower if you ever move them to another gun.

If you want to go outside Extar's ecosystem, the LaRue MBT-2S and CMC single-stage triggers are popular on r/extar. These need a small metal tuning plate under the tension screws to protect the polymer receiver which most aftermarket triggers do not include.

The EP9 ships without iron sights so an optic is not optional it is a requirement. The full-length Picatinny top rail accepts any red dot or prism scope with a standard mount. Here are the three best options by price and use case.

The Sig Sauer Romeo5 ($140) is the r/extar community favorite. MOTAC motion activation provides up to 40,000 hours of battery life, and the included low mount gives the right height for the EP9's polymer receiver. The Aimpoint T-1/T-2 footprint means any aftermarket mount fits.

The Holosun ARO ($144) is a fully enclosed emitter that protects the LED from rain, snow, and mud. The 50,000-hour battery and side-mounted tray mean no re-zeroing needed on battery changes. It is sold directly by Extar USA and includes a low mount specifically recommended for the EP Series. For an in-depth look at Holosun ARO vs Sig Romeo5, we have a dedicated comparison.

The Primary Arms SLx 1X MicroPrism with ACSS Gemini 9mm Reticle ($280) is the premium pick. The etched reticle works with or without battery, the prism design eliminates red dot starburst for astigmatic shooters, and the ACSS Gemini reticle is calibrated specifically for 9mm PCC ballistics with holdovers out to 200 yards.