Frequently Asked Questions

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• In-stock parts: ship within 2–5 business days via USPS Priority Mail.
• Orders with installed sights, single-color Cerakote, or assembly: estimated 7–10 business day lead time.
• Custom MultiCam / Camo Cerakote: estimated 2–3 business weeks.
• Customer slide & barrel porting services: estimated 4–8 business weeks.

All lead times are estimates only and subject to change without notice. Business days are Monday–Friday, excluding federal holidays, the week of Thanksgiving, and December 25 – January 1.

See our Shipping & Returns Policy for full details.

• USPS Priority Mail, calculated at checkout by package weight and destination
• Orders of $200+ ship signature-required, with no surcharge on standard shipping
• Free standard shipping on orders $500+
• California AB 1263 orders ship via USPS Priority Mail, Adult Signature Required

Orders over $200 ship signature required. Tracking numbers are provided for all USPS shipments. International and APO/FPO shipping is not offered unless arranged in advance.

Standard orders may be canceled within 24 hours of being submitted; cancellations after 24 hours carry a 20% cancellation fee. Custom, Cerakote, and special-order items (including Special Order Grip Modules) cannot be canceled once work has begun, and orders with custom Cerakote or installs cannot be changed once submitted. Shipping address changes can only be made before an order ships.

To request a cancellation or change, sign in and use Existing Order Question on our Contact page.

Eligible returns must be requested within 30 days from delivery. OEM parts and accessories must be in original, unused condition and sealed factory packaging. Items that are correct as ordered and returned at the customer’s request may be subject to a 20% restocking fee. Used or installed items cannot be returned (defect claims under our lifetime warranty are still honored).

All returns require an RMA number. Request one through Existing Order Question on our Contact page or email info@fdezwerx.com, then ship within 10 business days of RMA issuance to:

Fdez Werx
6012 Bayfield PKWY, STE 134
Concord, NC 28027

Full details are in our Shipping & Returns Policy.

Our slides are manufactured start to finish from solid stock in Concord, North Carolina, at our in-house facility on state-of-the-art HAAS VF2SS mills.

Slides are made of 416R stainless steel, stress relieved and heat-treat hardened to RC 42–44, and satin black DLC finished (unless otherwise specified) for a top-of-the-line look and corrosion and wear resistance.

All post-manufacturing processing, such as heat treat and DLC, is done locally in North Carolina.

Fdez Werx products have a lifetime warranty against manufacturing defects. No registration is required. If at any time during the life of your Fdez Werx product you encounter an issue not related to abuse or normal wear, please contact us immediately. A shipping label will be provided so that we can determine whether the item needs to be repaired or replaced.

• Please allow up to 2 weeks from the date received for warranty processing.
• Be sure to use the shipping label provided and include details about the issue you encountered.
• Items that have been modified or abused will have their warranty voided.
• Fdez Werx items are designed to work with OEM components and aftermarket components that meet OEM tolerance specifications. There is no guarantee our products will work with aftermarket or modified items outside of OEM standards.

Slides are sold stripped. Please read the product description in the listing for details on what is included. If you require internals, we offer authentic factory SIG SAUER parts.

The P365 and P320 are modular firearms, meaning that no matter which model you originally purchased, it can be interchanged with other P365 or P320 parts.

• P365 X/XL and XXL slides can be used with any P365 grip module and trigger assembly (FCU).
• P320 Compact slides can be used with X-Compact, X-Carry, Compact, Carry, and Subcompact grip modules.
• P320 Full-Size slides can be used with all P320 grip modules, including X5, AXG, Legion, X-Series, or standard.

See the compatibility charts below.

These backstraps are designed to be used with the P365 Macro grip module, also known as the P365 Carry grip module.

• P365 & P320 slides with SIG-LOC / RMSc / 407K / 507K / EPS optic mount: M4
• P365 slides with RMRcc optic mount: 5-40 x 5/16
• P320 Full-Size slides with RMR optic mount: 4-40 x 5/16

We have found that, on average, the velocity difference is roughly 50 fps, or less than 6%. This means the ported barrels have virtually no ballistic change while improving recoil mitigation.

We recommend using ammunition that is manufactured to meet or exceed SAAMI or other industry standards.

While some +P ammunition meets SAAMI guidelines, +P+ generally does not and is not recommended. This ammunition may generate higher pressures than standard ammunition and could shorten the life of the barrel or result in damage and an operating hazard to the shooter.

No. We recommend the use of jacketed ammunition only.

Due to variations between commercial and privately reloaded ammunition, we cannot warranty our products when used with reloaded ammo. We do warrant our barrels against defects in materials and workmanship when using new, factory ammunition.

The slide and barrel should be well lubricated with a thin, shiny layer of grease on the entire barrel exterior, slide rails, and chamber walls. Black nitride or stainless barrels are recommended during break-in, as PVD barrels are likely to show premature signs of wear if used during a new slide break-in process. New parts will require 200–300 rounds for break-in.

Slides are designed to function properly with the factory recoil spring assembly, but we do recommend an aftermarket adjustable recoil spring system. This will allow you to tune your firearm to its best performance based on the ammo type(s) you intend to use.

Installation instructions:

1. Install the stepped spacer into the slide with the small end locating in the slide opening so that it sits flush with the end of the slide.
2. We recommend starting with a lighter spring option and working your way up as needed.
3. Install the spring on the guide rod.
4. Hold the slide in your left hand with the muzzle pointed away, using your hand to hold the spring in place.
5. Push the guide rod in with your right thumb until it locates on the barrel lug.

Tuning instructions:

1. Shoot each spring rate to first determine which rates reliably cycle in your firearm based on your ammo type, shooting style, specific firearm, and aftermarket add-ons.
2. Then shoot each of those spring rates in consecutive 5–6 shot groups at a small target.
3. Compare groupings and determine which spring provided the best follow-up shot grouping.

In general, you will most likely end up with a lighter spring rate than factory, unless a heavier rate is required due to add-on parts such as suppressors, thread-on comps, or other non-standard configurations.