Optic Mount for Aimpoint COA to SIG P320 Sig-LOC Slide Cut

If you’ve got a Sig Sauer P320 with the newer Sig-LOC optic cut and you’re looking to mount an Aimpoint COA, you’ve probably noticed that not every mount plays nice with that factory slide profile. This optic mount from Apex is built specifically to solve that problem — it’s a steel billet mount and clamp (black PVD finished) that locks the COA securely into the Sig-LOC footprint. No adapter plates, no shims, no guesswork. It’s a direct-fit solution that keeps the optic low and solid, and it’s designed to work with the factory loaded chamber indicator on the M17/M18 models.

Compatibility

• Sig Sauer P320 Legion (Sig-LOC optic cut)
• Sig Sauer M17 / M18 (military and civilian models with Sig-LOC cut)
• Other P320 models with the factory Sig-LOC slide cut
• Works with factory Loaded Chamber Indicator on M17/M18
• Uses Aimpoint A-Cut geometry

Key Features

• Machined from billet steel with black PVD finish
• Includes steel clamp for secure optic retention
• Thread locking patch pre-applied to all screws — no extra loctite needed
• Torque spec: 15 in-lb for all Apex screws
• 100% made in the USA

Install Difficulty

2 out of 5 — straightforward if you’ve mounted an optic before. You’ll need a torque driver (inch-pounds) and a small hex bit. The pre-applied thread locker saves you a step. We always recommend watching the install video on our site before you start.

Frequently Asked Questions

Will this mount work on a standard P320 slide without the Sig-LOC cut?

No — this mount is specifically designed for slides that have the Sig-LOC optic cut. If your slide uses a different footprint (like the standard Delta Point Pro cut), this won’t fit.

Do I need to remove the loaded chamber indicator on my M18?

No, that’s one of the reasons this mount was designed the way it was. It clears the factory LCI without any modification.

Is the backup iron sight add-on available now?

Not yet — the Apex COA BUIS set (which includes a replacement clamp with an integrated rear sight and a matching front sight) is coming soon. We’ll update the listing when it’s in stock.

We ship from our shop in the USA within one business day. If something doesn’t fit or you have questions, just call us — we’re a family-run shop and we stand behind every part we sell. This mount carries our standard warranty against defects in materials or workmanship.