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Flux Raider · Volume 6

Accessories and the Aftermarket Around the Raider X

What mounts to the chassis, what mounts to the slide, what goes on the muzzle, and which of it follows a pistol from one build to the next

Flux’s “Raider X P320 Accessories” category listed 29 items on 19 September 2026, most of them made by other companies and resold by Flux.1 That is the practical aftermarket for the chassis: a handful of small makers, chiefly Tactical Development, building parts for one specific polymer housing, with Flux curating the list. This volume sorts it by where each part mounts, because that decides what happens to the part when a pistol moves from one chassis to another — the question Volume 7 turns on.

Prices are Flux’s listed prices on 19 September 2026 unless another source is named. “Out” means shown out of stock that day.

Figure 1 — A Raider X built up as Flux photographs it: red dot on the hood, light on the bottom rail, brace extended. Every accessory in the photograph is an add-on; the chassis ships with none of them.
Figure 1 — A Raider X built up as Flux photographs it: red dot on the hood, light on the bottom rail, brace extended. Every accessory in the photograph is an add-on; the chassis ships with none of them.

6.1 Parts That Belong to the Chassis

These stay with the chassis if the pistol is removed.

Table 1 — Parts That Belong to the Chassis

ItemMakerPriceNote
Side Accessory Pic Rails (pair, SKU 165-00006)Flux$49.99”3 slot picatinny rails to accommodate rail mounted lasers and lights … textured and slanted ends to provide more comfortable support hand placement.” Left and right rails, two backing plates, four screws; thread-locker per SIG’s manual (Volume 5)
RH / LH Brace Kit (165-00002 / 165-00013)Flux$49.99 eachbrace only; “rails and braces are tuned to fit each other in production”
SBR Stock Kit (RAIDERSTOCK)Flux$69.99SM (flush), MD or LG, each “for MP17” or “for X”; “ALL NFA RULES APPLY”; includes the matching gas cap
Gas Cap (165-00015)Flux$19.99four versions: MP17 or X, brace/flush or +1.5/+3 in stocks; “for use with suppressors”
Safety DeleteFlux$7.99replaces one side of the chassis safety; right or left
Slide Drop Release Lever (165-00001)Flux$9.99optional; warnings below
Extra Parts Kit (165-00014)Flux$7.99battery tray, hex key, “replacement springs”
Forward Operating PedalTactical Development$44.00 (out)thumb ledge, left or right side; “for the P320 Flux Raider X and P320 Flux Raider MP17”
Forward Halo Accessory Shroud (162-00118)Tactical Development$139.98front shroud, M-LOK, 12 o’clock rail
FOP for Raider X HaloTactical Development$19.89 (out)pedal for the Halo’s lower screw holes
LORA Rail (162-00102)Tactical Development$89.89 (out)“LOwer RAil”; 1913 plus M-LOK
Spare Mag Extension – Raider X (162-00119)Tactical Development$38.99 (out)lengthens the forward well’s grip area
HandleItGrips for Raider XHandleItGrips$22.99grip-panel patterns
Ripcord SlingFlux$39.99QD or HK hook; “military parachute webbing – 600lb rating”

Sources: the individual Flux listings.234567891011121314

Figure 2 — One of Flux's side M1913 rails: three slots on a moulded base with textured, angled ends. The rails are side-specific and marked; SIG's manual specifies a drop of thread-locker on each screw.
Figure 2 — One of Flux's side M1913 rails: three slots on a moulded base with textured, angled ends. The rails are side-specific and marked; SIG's manual specifies a drop of thread-locker on each screw.

6.1.1 The brace, the stocks and the gas cap

The standard Raider X ships with a right-handed brace. Flux sells a left-handed brace and three stocks separately, and each swap involves the rear end cap, which Flux calls a gas cap. The compatibility rule, from Flux: “The brace gas caps are not compatible with the MEDIUM and LARGE stocks. The brace gas caps are compatible with the FLUSH stock,” and the stock kits “come with the compatible gas cap for their chassis.”4 SIG’s manual gives the swap to a stock step by step: remove the brace end cap by pushing it up, slide on the stock’s end cap until it clicks, remove the two brace screws with the 5/64-inch key, press the stock onto the rails and fit the two stock screws — “Do not overtighten.”15

Figure 3 — A Raider X with the medium stock from Flux's catalogue. The stock replaces the brace on the same two extension rails. On a P320 barrel it makes the weapon a short-barrelled rifle, and SIG's manual …
Figure 3 — A Raider X with the medium stock from Flux's catalogue. The stock replaces the brace on the same two extension rails. On a P320 barrel it makes the weapon a short-barrelled rifle, and SIG's manual warns that registration and approval come before the stock goes on.

The stock is the one accessory in this volume that changes the weapon’s legal category. Volume 7 covers that as a per-build decision; the law itself is in the SIG P320-M17 dive, Volume 5.

Both brace kits carry the same caution, and it matters to anyone planning to swap braces or stocks between chassis: “because our rails and braces are tuned to fit each other in production, there is a chance that installing the brace will change the performance of the spring loaded ejection. That means the rails and brace will need to be tuned to work together. If you are having a rough time getting the ejection to work we are offering an install and tune up service.”3 A brace is not a free-floating spare that fits any chassis equally well.

Figure 4 — The Raider X with Flux's left-handed brace, which folds to the opposite side. On 19 September 2026 only right-handed brace versions of the chassis were selectable on Flux's page; the left-handed br…
Figure 4 — The Raider X with Flux's left-handed brace, which folds to the opposite side. On 19 September 2026 only right-handed brace versions of the chassis were selectable on Flux's page; the left-handed brace was sold as a kit.

The gas cap’s other job is gas. Flux sells alternative caps “for use with suppressors. This addition cuts off the gasses escaping directly backwards from the slide,” which is the chassis’s answer to its own FAQ’s warning that “Shooting suppressed can result in more gas being blown back towards you.”516

Figure 5 — Flux's gas cap for the brace and the flush stock: the rear end cap of the chassis, which slides onto dovetails. The medium and long stocks need their own caps.
Figure 5 — Flux's gas cap for the brace and the flush stock: the rear end cap of the chassis, which slides onto dovetails. The medium and long stocks need their own caps.

6.1.2 The safety delete, and the other safety delete

Flux’s Safety Delete and Armory Craft’s “Safety Delete For The FLUX RAIDER Brace” ($9.95, right or left) are the same kind of part: a button that takes the place of one side of the chassis’s own ambidextrous safety lever, so that the safety is worked from one side only. Armory Craft’s product photograph shows its button in the chassis beside the FIRE and SAFE markings.617

Figure 6 — Armory Craft's right-side safety delete for the Raider, from the maker's product page, seated in the chassis in place of one lever of the chassis safety beside the FIRE and SAFE markings.
Figure 6 — Armory Craft's right-side safety delete for the Raider, from the maker's product page, seated in the chassis in place of one lever of the chassis safety beside the FIRE and SAFE markings.

Neither is the part that removes an M17’s thumb safety from its FCU. That part — SIG’s safety-lever pin or an aftermarket FCU kit — is a fire-control-unit part, treated in the SIG P320-M17 dive, Volume 4. The two share a name and nothing else (Volume 3).

6.1.3 The slide-drop lever — an accessory with a warning attached

Flux’s $9.99 Slide Drop Release Lever lets the brace-release lever also drop the slide during a reload. Flux’s own listing is a caution more than a sales text: “The Raider X does not come with this option stock from the factory due to feedback given over the last several years. ATTENTION: This replacement part may not work depending on the tolerances of your FCU or slide. In some cases, you may need to modify your FCU by installing an extended slide stop/release. You may need to adjust tolerances on your slide with a file … WARNING: Because this part was not designed for the Raider X, it may cause your brace/stock rails to collapse under recoil if not installed and tuned correctly.”7

Figure 7 — Flux's optional slide-drop release lever: a replacement brace-release lever with an extension that also bears on the P320's slide catch.
Figure 7 — Flux's optional slide-drop release lever: a replacement brace-release lever with an extension that also bears on the P320's slide catch.

Read against Volume 3, the warning is specific: the part replaces the lever that releases the brace lock, and a brace lock that releases under recoil is the failure the 2021 Raider Fix addressed. The part also invites FCU and slide modification, which SIG’s manuals reserve to its armorers. It is listed here for completeness, not recommended for a build.

6.1.4 The Forward Halo and the LORA

Tactical Development’s two front-end parts extend the chassis forward.

The Forward Halo is “a front mounted accessory rail for the Flux Raider X -P320 and SIG Flux Legion,” with M-LOK points, a “Fixed 12 o’clock 1913 rail for forward optic mounting,” and the maker’s list of benefits: “Larger eye box/eye relief when optic mount on Halo,” “Night vision compatible,” “Weight added up front for reduced felt recoil.” It is “Suppressor compatible (limited diameter sizes, with slide/barrel lengths see chart),” and gives a rule of thumb: on a compact slide, a suppressor under 1.4 in in diameter 1–2 in from its threaded end is likely to fit; on a full-size barrel, under 1.6 in about ½ in from the end.10

The LORA (“LOwer RAil”) slides on at the front of the chassis and is fixed with one screw — the only fastener in the Raider X line for which a torque is published: “tighten screw to 20in.lbs.”11

⚠ The LORA’s own listing suggests fitting a vertical fore grip. Its copy reads, in part, “side mount a laser, add a VFG or Angled grip!”11 On a Raider X with a brace — a pistol — a vertical fore grip is the case ATF’s 2006 open letter addresses: in ATF’s words, installing one on a handgun means the owner is “‘making’ a firearm requiring registration” as an any other weapon. That letter and what it does and does not reach are set out in the SIG P320-M17 dive, Volume 5. An accessory maker’s product copy is not a classification, and a rail that will accept a vertical grip is not permission to fit one.

6.1.5 The spare-magazine extension

Tactical Development’s extension “seamlessly extends the front spare magazine grip length. Simply slide it over the existing spare mag—zero tools or permanent modifications required.” It is “Compatible with MP17, Raider X, and Flux Legion,” with a note that “Cerakote or other finish added to your Raider may make this not seat full. Holster fitment may change with this added.”12 Flux’s own position, printed on its product pages, is that the forward well “is designed and intended only as a spare mag carrier, not as a vertical grip.”18 An extension marketed to lengthen that well’s “grip length” sits awkwardly beside that statement; Volume 7 records it without resolving it, because no ATF statement on either was located.

6.2 Parts That Belong to the Slide

These move with the slide, not the chassis.

Table 2 — Parts That Belong to the Slide

ItemMakerPriceNote
RipStik side charging handleTactical Development$95.00 / $120.00front-sight channel; blackout or tritium; left or right
F10 top charging handleTactical Development$95.00front-sight channel; “originally design for the Flux Raider”
Velocity / Flux slide (full-size)Killer Innovations$525.00 (out)17-4 stainless; DPP/RMR optic cut; handle dovetails at 3, 9, 12 o’clock; “Slides are sold stripped”
Charger Grip TapeFlux$9.99”Laser cut to M17/P320 slide surface measurements”
P320 Takedown ToolTactical Development$20.89—

Sources: Tactical Development’s RipStik page and Flux’s listings.1920212223 The RipStik on the build in the P320 dive, and its maker’s warning never to hammer it in, are in the SIG P320-M17 dive, Volume 4. Both charging handles are “Not Compatible with Grey Ghost Slides as their sight channel is not to SIG specifications.”20

6.3 Parts That Belong to the Muzzle

Table 3 — Parts That Belong to the Muzzle

ItemMakerPriceNote
SilencerCo threaded barrel, full-size or compact P320SilencerCo$169.00”that we recommend for Suppressor and Compensator use”
HC320R “Flush Two Port” compensatorHerrington Arms$99.997075 aluminium; 1.6 in long; “will make your x carry 3.9″ slide flush with the end of the Raider chassis”; the maker recommends a spring kit
HC320XL compensatorHerrington Arms$89.99 (out)6061; 1.23 in; “Works great with stock springs”
Velocity Pro Tucked CompKiller Innovations$135.00not recommended by its maker on OEM SIG threaded barrels
Velocity barrel, full-size or compactKiller Innovations$283.00416R; ½-28
Recoil Spring Kit (X-Carry only)Flux$49.99 (out)12, 14, 16, 18 lb; “to tune the cyclic rate and balance when shooting suppressed”

Sources: Flux’s listings.242526272829 The compensator, spring and threaded barrel on the build in the P320 dive, and the reasoning about why a compensator forces a lighter spring, are in the SIG P320-M17 dive, Volume 6. Two chassis-specific points are worth adding:

  • The HC320R was designed for this chassis. Herrington’s text: “The HC320R is 3/8″ longer than the HC320XL and has larger top ports to reduce more recoil and sit flush with the end of the Raider chassis. We designed the HC320R specifically for the guys running the Flux Defense Raider Chassis.”25 On a 3.9-inch slide, where a muzzle device is compulsory (Volume 4), it is the device that ends where the chassis ends.
  • Suppressed, Flux advises a heavier spring than most compensator users fit. “For the Raider X, it is highly encouraged to use a nicely broken in 14lbs spring with most suppressors on the market.”16 Flux also collects owners’ suppressed-build results on a public data-entry page, “Form created to collect user feedback on suppressed Raider builds.”30

6.4 Magazines, Holsters and Carriers

  • Magazines. Flux resells SIG’s “OEM P320 magazines. 21 and 30 round capacity” at $49.99 (out of stock on 19 September 2026); SIG listed its own 30-round magazine at $59.99 on a July 2026 capture.3132 Which magazines fit is in Volume 4.
  • Holsters. Flux’s support page: “The in house holster project has been delayed but we have found several different 3rd party Raider holsters to work great like the Gray Fox Strategic holster,” naming a product called “flux-capacitor” at grayfoxstrategic.ca; and “The old MP17 holster was not compatible with the Raider.”33 The Gray Fox Strategic page was not examined, and no fit claim is made for it here beyond Flux’s.
  • Magazine carriers. Flux lists the Snakestaff Systems Cantable Mag Carrier ($34.99), an inside-the-waistband carrier promoted for the Raider 365.34

6.5 What Carries Between Builds

The sorting above is the point of this volume. When a pistol is planned for a new chassis, each accessory falls into one of three groups:

  • Chassis parts — side rails, pedal, Halo, LORA, gas cap, safety delete, brace or stock, sling — are bought again for every chassis, or moved with care. A brace or stock moved between chassis may need Flux’s tuning service.
  • Slide and muzzle parts — charging handle, threaded barrel, compensator, guide rod and spring — go wherever the slide goes.
  • Optics and lights clamp to 1913 rails and move freely between chassis, subject to re-zeroing.

Volume 7 applies that to the parts on the existing build.

References

Footnotes

  1. Flux Defense, “Raider X P320 Accessories” category, “Showing 1–12 of 29 results.” https://fluxdefense.com/product-category/accessories/raider-x-p320-accessories (accessed 2026-09-19). ↩

  2. Flux Defense, “Side Accessory Pic Rails,” SKU 165-00006, $49.99. https://fluxdefense.com/shop/side-accessory-pic-rails (accessed 2026-09-19). ↩

  3. Flux Defense, “RH Brace Kit – Raider X P320,” SKU 165-00002, and “LH Brace Kit – Raider X P320,” SKU 165-00013. https://fluxdefense.com/shop/rh-brace-kit-raiderxp320 ; https://fluxdefense.com/shop/lh-brace-kit-raiderxp320 (accessed 2026-09-19). ↩ ↩2

  4. Flux Defense, “SBR Stock Kit – Raider X P320,” SKU RAIDERSTOCK, $69.99. https://fluxdefense.com/shop/sbr-stock-kit-raiderxp320 (accessed 2026-09-19). ↩ ↩2

  5. Flux Defense, “Gas Cap,” SKU 165-00015, $19.99. https://fluxdefense.com/shop/gas-cap (accessed 2026-09-19). ↩ ↩2

  6. Flux Defense, “Safety Delete,” $7.99. https://fluxdefense.com/shop/safety-delete (accessed 2026-09-19). ↩ ↩2

  7. Flux Defense, “Slide Drop Release Lever,” SKU 165-00001, $9.99. https://fluxdefense.com/shop/slide-drop-release-lever (accessed 2026-09-19). ↩ ↩2

  8. Flux Defense, “Extra Parts Kit,” SKU 165-00014, $7.99. https://fluxdefense.com/shop/extra-parts-kit (accessed 2026-09-19). ↩

  9. Flux Defense, “Tactical Development Forward Operating Pedal,” $44.00. https://fluxdefense.com/shop/tactical-development-forward-operating-pedal (accessed 2026-09-19). ↩

  10. Flux Defense, “Forward Halo Accessory Shroud for Raider X P320,” SKU 162-00118, $139.98. https://fluxdefense.com/shop/forward-halo-accessory-shroud-for-raider-x-p320 (accessed 2026-09-19). ↩ ↩2

  11. Flux Defense, “LORA Rail,” SKU 162-00102, $89.89. https://fluxdefense.com/shop/lora-rail (accessed 2026-09-19). ↩ ↩2 ↩3

  12. Flux Defense, “Tactical Development Spare Mag Extension – Raider X,” SKU 162-00119, $38.99. https://fluxdefense.com/shop/spare-mag-extension-raider-x (accessed 2026-09-19). ↩ ↩2

  13. Flux Defense, “HandleItGrips for Raider X,” $22.99. https://fluxdefense.com/shop/handleitgrips-for-raider-x (accessed 2026-09-19). ↩

  14. Flux Defense, “Ripcord Sling,” $39.99. https://fluxdefense.com/shop/ripcord-sling (accessed 2026-09-19). ↩

  15. SIG Sauer, SIG P320 Raider X Operator’s Manual, P/N 1304128-01 REV 02, §12.0 “Install Optional SBR Stock.” https://www.sigsauer.com/media/sigsauer/resources/FLUX_RAIDER_BRACE_OPERATORS_MANUAL_1304128-01_REV_02_WEB_UPDATE_1.pdf (downloaded 2026-09-19). ↩

  16. Flux Defense, “Frequently Asked Questions,” items 33 and 47. https://fluxdefense.com/frequently-asked-questions (accessed 2026-09-19). ↩ ↩2

  17. Armory Craft, “Safety Delete For The FLUX RAIDER Brace,” $9.95; product photograph reproduced. https://www.armorycraft.com/product-page/safety-delete-for-the-flux-raider-brace (accessed 2026-09-19). ↩

  18. Flux Defense, “Raider X BLEM – P320.” https://fluxdefense.com/shop/raider-x-blem-p320 (accessed 2026-09-19). ↩

  19. Tactical Development, “RipStik - Charging Handle for Sig Sauer P320.” https://tactical.dev/products/charging-handle-for-sig-sauer-p320 (prices as recorded by the SIG P320-M17 dive’s research, 2026-09-19). ↩

  20. Flux Defense, “F10 Top Charging Handle,” SKU 162-00005, $95.00. https://fluxdefense.com/shop/f10-top-charging-handle (accessed 2026-09-19). ↩ ↩2

  21. Flux Defense, “Killer Innovations Velocity Slide,” $525.00. https://fluxdefense.com/shop/velocity-slide-raider (accessed 2026-09-19). ↩

  22. Flux Defense, “Charger Grip Tape,” SKU 165-00003, $9.99. https://fluxdefense.com/shop/charger-grip-tape (accessed 2026-09-19). ↩

  23. Flux Defense, “Tac Dev P320 Takedown Tool,” $20.89. https://fluxdefense.com/shop/tac-dev-p320-takedown-tool (accessed 2026-09-19). ↩

  24. Flux Defense, “Silencer Co Threaded Barrels,” $169.00. https://fluxdefense.com/shop/threaded-barrels (accessed 2026-09-19). ↩

  25. Flux Defense, “Flush Two Port Compensator” (Herrington Arms HC320R), $99.99. https://fluxdefense.com/shop/flush-two-port-compensator (accessed 2026-09-19). ↩ ↩2

  26. Flux Defense, “HC320XL Compensator,” $89.99. https://fluxdefense.com/shop/hc320xl-compensator (accessed 2026-09-19). ↩

  27. Flux Defense, “Killer Innovations Velocity Compensator,” $135.00. https://fluxdefense.com/shop/velocity-compensator (accessed 2026-09-19). ↩

  28. Flux Defense, “Killer Innovations Velocity Barrel,” $283.00. https://fluxdefense.com/shop/velocity-barrel (accessed 2026-09-19). ↩

  29. Flux Defense, “Recoil Spring Kit,” SKU 162-00018, $49.99. https://fluxdefense.com/shop/recoil-spring-kit (accessed 2026-09-19). ↩

  30. Flux Defense, “Suppressed Raider Data.” https://fluxdefense.com/support/raider-suppressor-data-entry (accessed 2026-09-19). ↩

  31. Flux Defense, “Sig Sauer P320 Magazines,” $49.99. https://fluxdefense.com/shop/sig-sauer-p320-magazines (accessed 2026-09-19). ↩

  32. SIG Sauer, “P320-FLUX LEGION,” related-products listing; Internet Archive capture of 27 July 2026. https://web.archive.org/web/20260727211102/https://www.sigsauer.com/p320-flux-legion.html ↩

  33. Flux Defense, “Support,” item 6. https://fluxdefense.com/support (accessed 2026-09-19). ↩

  34. Flux Defense, “Cantable Mag Carrier – Snakestaff Systems,” $34.99. https://fluxdefense.com/shop/cantable-mag-carrier-snakestaff-systems (accessed 2026-09-19). ↩

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