Glock 45 MOS Upgrades: Optics, Triggers & Lights Ranked

The Glock 45 is the only mainstream Glock that splits its upgrade compatibility down the middle. Anything tied to the grip frame (triggers, magazines, mag catches, magwells, Talon Grips, the SCD) shares with the Glock 17 Gen5. Anything tied to the slide (barrels, slide cuts, optic plates) shares with the Glock 19. Sights and weapon lights cross both because the dovetail and rail are universal Glock standards.

Critical mistake to avoid: Buying a G17-length barrel or slide for your G45. The G17 runs a 4.49-inch barrel, the G45 runs a 4.02-inch G19 barrel. A G17 barrel will not fit a G45 slide. Always buy G19 barrels and G19 slides for G45 upgrades. For shared parts, the G17 Gen5 path applies. See our Glock 17 upgrades guide for the trigger and frame product rationale, and our Glock 19 upgrades guide for the slide and barrel context. Build your G45 in our rifle builder to see how parts pair with the host frame.

The order that gives you the most capability per dollar on a Glock 45 MOS. Skip cosmetic mods until every priority above is handled.

Key insight: The G45 ships MOS-standard, so the most expensive upgrade most shooters never make is just mounting an optic to the plate that came with the gun. If you do nothing else, mount a 507C or RMR. The factory plates are sitting in the box for a reason. For a deeper breakdown of pistol optic footprints, see our best pistol red dot guide. If you are still shopping platforms, our best full-size 9mm pistols guide ranks the G45 against the P320, M&P 2.0 5", CZ P-10F, and Walther PDP F-Series.

Why magazines come first: The Glock 45 takes Glock 17 magazines directly, which makes it the easiest Glock to mag-stack on the planet. G17 magazines are the most widely produced 9mm pistol magazines in the world, prices are low, OEM availability is constant, and building a 10-magazine training stack costs less than a single premium upgrade. Stock up before you spend a dollar on anything else.

How many magazines do you need: For everyday carry, two minimum, one in the gun and one on body. For home defense, three to four staged around the home gives you redundancy without logistics complexity. For range and competition work, ten magazines is the practical floor for a full training day without constant reloading breaks. Add a Taran Tactical Firepower Base Pad +5 ($42) to bedside or competition mags to push capacity to 22+1 in a single stick. The G45 ships with 17+1; 33-round Glock factory extended mags are federally legal and useful for staging.

Cross-compatibility with other Glocks: The G45 takes G17 mags directly, including OEM 17-round, OEM 33-round, Magpul PMAG 17 GL9, and PMAG 21 GL9. G19 15-round magazines also fit but leave a gap at the base of the grip (the G45 has the longer G17 grip). G17 mags also drop into the G19 and G26 frames, which makes the G17/G45 mag your cross-platform standard if you own multiple Glocks. Buy OEM G17 magazines for carry reliability and PMAG GL9 for training volume at a meaningfully lower per-unit cost.

What a fully upgraded G45 MOS costs at three budget levels. The factory G45 MOS starts around $649.

Budget ($591): Talon Grips, compact light, factory MOS optic, Apex trigger, three training mags. Covers 90% of what most owners need. Mid ($1,173): Adds duty-grade light, suppressor-height sights, match barrel, Striker Control Device, OEM mag stack. Premium ($1,968): Trijicon RMR, X300U-A, Radian RAMJET comp, magwell, and a full mag stack with TTI extensions for bedside duty.

Best Glock 17 Upgrades 2026 - The full-size G17 upgrade path. Triggers, magazines, mag catches, magwells, and Talon Grips all cross-fit the G45 because the G45 carries the G17 Gen5 frame.

Best Glock 19 Upgrades 2026 - The compact G19 upgrade path. Barrels and slides cross-fit the G45 because the G45 uses the G19 slide pattern. Buy G19-length parts for any G45 slide-side upgrade.

Best Full-Size 9mm Pistols 2026 - Platform comparison if you are still weighing the G45 against the P320, M&P 2.0 5", CZ P-10F, Walther PDP F-Series, and other full-size 9mm hosts.

Glock Gen 5 vs Gen 6 2026 - What Gen 6 changes (revised trigger housing, undercut trigger guard, fixed beavertail) and which Gen5 aftermarket parts from this guide still drop into a Gen6 G45.

Best Glock Barrels 2026 - Cross-model match, threaded, and integrated comp barrel rankings spanning G17, G19, G34, G43X, and G48 with G45 fitment notes.

Best Glock Triggers 2026 - Cross-model trigger rankings including Glock Performance Trigger, Overwatch DAT, Timney Alpha, and Apex AEK with Gen5 and Gen6 fitment breakdowns.

Best Pistol Red Dot Sights 2026 - Every pistol optic footprint ranked with battery life, emitter type, and durability for MOS-ready guns including the G45.

Best Pistol Lights 2026 - Streamlight, SureFire, Modlite, and Inforce ranked with lumens-vs-candela breakdowns and holster compatibility notes for full-size pistol rails.

Best Glock 19 Compensators 2026 - Stand-alone comps and barrel+comp systems. Most options cross-fit the G45 because the G45 uses the G19 slide.

Best Concealed Carry Holsters 2026 - IWB, AIWB, and OWB holsters ranked with G45 and G17-pattern fit notes.