S&W M&P FPC Accessories & Upgrades 2026: Triggers, Optics, Mags

Quick Answer: What To Upgrade First

Buy the M*CARBO charging-handle kit first, the trigger spring kit second, and a fold-surviving red dot third. The factory charging handle is a small plastic wing that is awkward to work and gets in the way of a clean cheek weld, and the kit that fixes it also adds a receiver rail so you can mount a red dot back near your eye, so it earns the top spot. The $19.95 trigger spring kit is the cheapest meaningful upgrade on the platform. Everything after that, optics, a muzzle brake or suppressor, spare mags, and a sling, depends on whether the FPC is a range plinker, a home-defense gun, or a folded pack gun.

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Charging Handle: A Common First Upgrade

The factory charging handle is a small plastic wing, and a common first upgrade is M*CARBO's Extended Charging Handle & Pic Rail Mount kit ($149.95). The stock handle is a non-reciprocating paddle behind the receiver that is stiff and slick out of the box and sits where it fights a clean cheek-to-stock weld. The kit replaces it with an extended metal handle and a rapid deployment latch for a faster, more positive charging stroke and a cleaner cheek weld, and it bundles a CNC Picatinny rail on the receiver so you can mount a red dot back near your eye instead of far forward on the factory forend rail. It is a direct-fit install with no gunsmithing, it is confirmed for the 9mm and 10mm FPC, and it is the priciest single FPC part in M*CARBO's line, so buy it for the ergonomics-plus-optic-position combination rather than as a standalone luxury. It is frequently on back order, so buy it when you see it in stock.

Trigger Upgrades: Spring Kit First, Flat Shoe For Feel

The FPC trigger spring kit ($19.95) is the biggest felt improvement per dollar on the whole platform. Swapping the hammer, sear, and firing-pin springs drops the pull roughly 40%, from about 3.7 lb to 2.25 lb, without giving up reliability. It takes basic hand tools and a fire-control disassembly, not a gunsmith. The one caveat that matters: it is listed for the 9mm FPC only, not the FPC .22LR, whose rimfire fire control needs full hammer energy to light primers reliably.

The M*CARBO FPC Flat Trigger ($64.95) is the other half of the trigger job. It is a CNC flat-face shoe with a finger groove that cleans up the break and shortens the perceived reach to the trigger, a direct shoe swap. It changes geometry, not pull weight, so on its own it is a feel upgrade rather than a lighter pull. Run the two together, spring kit for weight and flat shoe for shape, if you want the trigger fully handled. If you can only buy one, buy the spring kit.

Optics That Survive The Fold

The best red dot for the FPC is a rugged pistol dot on a low RMR mount over the factory Picatinny rail, where it holds zero through the fold. The Holosun 507COMP ($369.99) is the pick: an open reflex with a huge competition window, 1.1 by 0.87 inch and about 67% larger than a 507C, and Holosun's multi-reticle system, backed by Shake Awake and a long battery life on an IP67-sealed, RMR-pattern base. The oversized window is the whole point on a carbine, it makes target acquisition fast and keeps both eyes open, where a micro dot's small window slows you down. It is the priciest optic here and physically larger, so mount it low to keep the folded barrel clear of the glass, but it is the right answer for a home-defense or match-focused FPC.

If you want the value pick, the Holosun 507C X2 ($232.99) shares the same RMR footprint and rides an RMR mount on the FPC's Picatinny rail, whether the factory forend rail or the M*CARBO receiver rail, runs the same multi-reticle system, adds a solar failsafe, and sits low and light while holding zero. The tradeoff versus the 507COMP is a smaller window and sight picture, and you will want a riser if you care about a lower-third co-witness. Either dot drops onto a virtual FPC in the rifle builder so you can see how the optic, trigger, and charging-handle picks stack up before you buy.

Muzzle Devices & Suppressors

The FPC threads 1/2x28 at the muzzle, which opens two paths: a brake now or a suppressor later. The M*CARBO FPC Muzzle Brake ($64.95) is the cheap, immediate option, an FPC-specific 1/2x28 brake that flattens what little recoil the gun makes for faster splits and threads straight on. Be honest about the payoff: a 16-inch blowback 9mm is already soft, so the brake is a refinement that adds blast and noise more than it transforms the gun. The 9mm brake is a separate part from M*CARBO's 10mm version, so match it to your caliber.

A can is the bigger upgrade, and the federal making and transfer tax on suppressors is now $0 as of January 1, 2026, so the barrier is an ATF Form 4 and a NICS check, not a $200 stamp, with eForm 4 approvals currently running days to a couple of weeks. The SilencerCo Omega 9K ($749) is the compact-9 benchmark at 4.5 inches and 7.3 oz, threading onto the FPC via a 1/2x28 piston and rated for both pistol and PCC use, the pick if you want the shortest, lightest can. The Rugged Obsidian 9 ($842) is the modular alternative: it runs full-size or short and ships with a 1/2x28 piston, so it is the better crossover if you want to tune length rather than commit to one size. Suppressors are legal to own in 42 states, and state law still applies. For a deeper look at 9mm host-and-can pairings, see the PCC suppressor pairing guide.

Light & Sling: Carry The Folder

For a home-defense FPC, a weapon light and a sling are the last two accessories that matter. The Streamlight TLR-7 X ($169) is compact enough for the FPC forend, bright enough for a defensive role, and uses ambi paddle switching that suits a two-handed carbine grip; you will need an M-LOK or rail adapter to hang it, and it is more than a slung field gun needs. The Magpul MS1 Sling ($44.95) is the carry pick, a two-point sling with quick length adjustment that suits a gun you deploy and stow often, built on durable nylon webbing and QD-compatible mounting, though some setups need the QD hardware bought separately. For where the FPC fits as a packable, fold-flat option, see the best truck gun guide, and for the variant that swaps 9mm for 5.7x28, read the FPC 5.7 launch coverage.