A place with answers to all your questions




What warranty do Fdez Werx items have?

Fdez Werx products have a lifetime warranty. No purchase 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 reach out to us immediately so that we can determine if the item needs to be replaced. 


What is the ballistic drop between the XL ported and non-ported barrel?

We have found that on average velocity difference is less than 3%. This means the ported barrels have virtually no ballistic change while improving recoil mitigation. 


What optic screws does my slide use?

P365 & P320 slides with RMSc / 407K / 507K / EPS optic mount use M3-0.5 X 10mm

P365 slides with RMRcc optic mount use 5-40 X 5/16

P320 Full-size slide with RMR optic mount 4-40 X 5/16


What recoil spring is recommended for my slide?

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


What ammo type is recommended for the Fdez Werx slides?

Our slides are design and tested to function with all standard 9mm ammo. For best recoil mitigation performance of the integral comp system we recommend standard 124-147gr ammo.


What is slide and barrel break in recommendations?

Slide and barrels should be well lubricated on entire barrel exterior and slide rails and chamber walls with a thin shiny layer of grease. 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.


What model firearms do the FDEZ Back straps fit on?

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


What slide can I use with my P365 or P320?

The P365 and P320 are modular firearms meaning that no matter the 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 with all P320 grip modules including X5, AXG, Legion, X-series or standard 


Do slides come with internals? 

Slides are sold stripped and will require internals. If you do need to purchase internals we offer factory SIG SAUER authentic parts on the website under Parts & Accessories 


When will my order ship?

In stock items with no add options usually ship within 1-2 business days 

Orders with added installed sights and or single color cerakote have an estimated 7-10 business day lead time.

Orders with added camo Multicam Cerakote will have an estimated 2-3 week lead time. 

Order with added stippling will have an additional estimated 4+ week lead time.

All lead times are estimates only and subject to change without notice.

Business days are Monday -Friday 

excluding federal holidays and the week of Thanks Giving, and Dec 25th-Jan1st.


Why is my credit card being declined?

Due to high levels of fraud our system requires an exact zip code match to what your card provider has on file. Please try both the 5 digit & 9 digit versions of your zip code.