Cut Your Slide

Slide Milling Service

Sig P320 Optic Cut

Optic cut for every P320 — X-Carry, X-Compact, X-Five, AXG, M17/M18, and beyond. RMR, Holosun, ACRO/ROMEO2, DPP, and ROMEO1PRO conversions starting at $150. Slide-only shipping, no FFL transfer required.

Place an Order — $150 See Full Pricing

Slide-Only Shipping

P320 FCU stays with you, no FFL needed

7-Business-Day Turnaround

From slide receipt to shipped-back

Direct-Mount Precision

No plate, no wobble, no zero shift

Why P320 owners ship just the slide

The P320's claim to fame is the modular Fire Control Unit — the serialized component that defines the gun under federal law. The slide itself isn't a firearm: it's a parts kit. That means you can ship your P320 slide to us in a regular USPS box, no FFL transfer, no pistol box requirements, no weeks-long paperwork delays.

Ship the slide (and the barrel if you want it inspected for fit). Keep the FCU in your safe. We mill the cut, ship the slide back, and you reassemble at home. The whole round-trip averages 10–14 calendar days because there's no FFL bottleneck.

For Glock, S&W, and most other platforms the slide is shipped freely under federal law as well — the FFL question only comes up if you ship a complete firearm. P320 just makes it especially obvious because the modularity is the whole point.

Footprints supported on the P320

Trijicon RMR / Holosun 507c

The most common cut. Fits the RMR family plus Holosun 507c, 407c, 508T, Swampfox Justice, and other RMR-pattern optics.

Aimpoint ACRO / ROMEO2 / Holosun 509T

Larger enclosed-emitter window. One cut, three optic options. Increasingly popular for duty and range guns.

Leupold Delta Point Pro

DPP footprint. Fits the DPP and DPP-pattern adapters. Lower-profile than the RMR.

ROMEO1PRO (Sig native)

Sig's native footprint for the ROMEO1PRO. Ships from Sig as an optic-ready slide; we can cut a non-OR slide to match if you've got a ROMEO1PRO and want to upgrade your existing slide.

Holosun 507K / Shield RMSc (subcompact slides)

For P320 Subcompact slides. The smaller footprint matches the slim-frame carry guns.

Custom / unlisted footprints

We mill custom cuts regularly. Add a note to your order with the optic make and model — we'll quote and confirm before milling.

Sig P320 optic cut — frequently asked questions

Which P320 models can you cut?
All of them. P320 X-Carry, X-Compact, X-Five (Legion and standard), X-Ten, AXG Carry, AXG Scorpion, AXG Pro, M17, M18, P320 Compact, P320 Spectre Comp, and the X-Five Carry. We can also cut P320 Subcompact slides for slim-frame footprints like RMSc and Holosun 507K.
I have a Sig optic-ready slide with the ROMEO1PRO cut. Can you mill it for an RMR or Holosun?
Yes. The ROMEO1PRO footprint is unique to Sig — it doesn't share dimensions with the RMR, Holosun 507c, or any common third-party optic. If you want to switch from a ROMEO to an RMR-pattern optic, we can re-cut the slide for the new footprint as long as the original ROMEO cut isn't already at the maximum allowable depth (we'll inspect on receipt and contact you if there's any concern).
What about the Sig ROMEO2 with the ACSS Vulcan reticle?
The ROMEO2 uses the same Aimpoint ACRO P-1 footprint that the Holosun 509T also uses. So a single ACRO cut on your P320 slide accepts the ROMEO2, the ACRO P-1 / P-2, and the Holosun 509T interchangeably. One of the most flexible cuts you can choose.
Will this affect the slide's nitride finish or fit on the frame?
No. We mill cold, so there's no heat distortion to the slide rails or barrel hood. The factory nitride finish remains intact everywhere except inside the optic cut itself, which is sealed by the optic body when mounted. Slide-to-frame fit and barrel lockup are unaffected.
What about the FCU? Do I need to send the whole pistol?
No — and please don't. P320s are unique in that the serialized component is the Fire Control Unit (FCU), not the slide. We only need the slide and barrel (and optionally the recoil spring assembly). The FCU stays with you, no FFL transfer is required, and shipping is much simpler.
How does shipping work for a Sig that doesn't need an FFL?
Same as any other slide — we email a prepaid USPS Ground Advantage label, you box up just the slide (and barrel if you want it inspected for fit), and drop it at any USPS location. Because the slide alone isn't a firearm under federal law, no FFL transfer is needed in either direction.

Cut your P320, ship just the slide

No FFL transfer, no paperwork delay. Sign up, ship the slide, get it back in 10–14 days.

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Sig P320 Optic Cut — RMR, Holosun, ROMEO from $150 | Cut Your Slide