The P320® Voluntary Upgrade Program is a SIG SAUER initiative to upgrade P320 pistols at no additional cost

This will include an alternate design that reduces the physical weight of the trigger, sear, and striker while additionally adding a mechanical disconnector.


3 Steps To Upgrading Your SIG SAUER P320 Pistol

  1. Enter your serial number to the right to see if your P320 has already been upgraded.
  2. If the message indicates your pistol has not been upgraded, reach out to SIG SAUER Customer Service at 603-610-3000 option 1 (8:30am – 5:00pm EST)
  3. Have your P320 serial number and home address available for the customer service representative.

PLEASE NOTE: Due to current global circumstances you may experience delayed response times when calling SIG SAUER Customer Service. We are working diligently to minimize wait times and ensure that customer calls are answered as promptly as possible. Thank you for your patience during these unprecedented times.

Once SIG SAUER receives your P320 pistol, they will apply the upgrades, test it, and then return it to you free of charge.

If you own multiple P320s, you will need to enter each P320 serial number separately.



All P320 pistol owners are eligible. Sign up online and get your P320 upgraded at no cost to you. 


For U.S. domestic consumer purchases, enter your registered P320 serial number below.


The pistol's serial number is stamped on the receiver.

How to locate your P320 Serial Number

Your P320 serial number can be found by looking on the right side of the pistol grip. The serial number will be stamped into the receiver. This number should be entered into the first entry field of the form. SKU will automatically populate if your P320 is on a qualified list of U.S. Domestic consumer serial numbers.

With some exceptions, most U.S. Domestic Consumer P320 serial numbers begin with “58A”, “58B”, or “58C”, followed by six numbers.

  • Example: 58Axxxxxx

NOTE: There are no “i”s or “o”s in the numerical portion of the serial number.


Explanation of Changes Made to the Pistol

Several important changes have taken place to bring an original SIG SAUER P320 pistol to its new upgraded status. These changes include an enhanced, upgraded trigger and slide.


Updated Slide

The updated slide will feature a disconnect notch near the striker assembly. The mechanical disconnector provides an additional level of safety against cartridge failure events.  Additionally, the mechanical disconnector prevents a “dead trigger” condition if the trigger is pulled while the slide is retracted.

These changes are expected to refine functionality for the pistol and improve both its ergonomics and performance.

Updated Trigger

The new trigger for the P320 pistol will feature a thinner profile and reduced mass. This is expected to improve the trigger-pull experience.




Is my P320 safe in its current configuration?

Yes. The P320 meets and exceeds all US safety standards. However, mechanical safeties are designed to augment, not replace safe handling practices. Careless and improper handling of any firearm can result in an unintentional discharge.

What is the P320 Voluntary Upgrade Program?

SIG SAUER is offering a voluntary program for P320 pistols. This will include an alternate design that reduces the physical weight of the trigger, sear, and striker while additionally adding a mechanical disconnector.

Why is this upgrade happening?

Through additional testing above and beyond standard American National Standards Institute (ANSI)/Sporting Arms & Ammunition Institute (SAAMI), National Institute of Justice (NIJ), Department of Justice (DOJ), Massachusetts, California, and other global military and law enforcement protocols, we have confirmed that usually after multiple drops, at certain angles and conditions, a potential discharge of the firearm may result when dropped. Although it is a rare occurrence, with very specific conditions, SIG SAUER is offering an upgrade to all of its current P320 owners.

Does the owner’s manual say it can be unsafe?

The language used in major manufacturers’ owner’s manuals with regard to drop safety is consistently written to warn the user that dropping a loaded firearm is not recommended and could possibly result in an accidental discharge. All precautions should be taken to avoid dropping a loaded firearm. Although extremely unlikely, it is still possible for any loaded firearm to discharge when dropped.

What calibers and models are affected?

Due to the modularity of the pistols, which all share the same trigger group, all calibers and pistol sizes are affected.

What type of ammunition was used during testing?

A variety of calibers and brands of ammunition were used. NOTE: Loaded ammunition is not used for drop testing, only primed cases with the powder and projectile removed are used.

What type of ammunition was used during testing?

A variety of calibers and brands of ammunition were used. NOTE: Loaded ammunition is not used for drop testing, only primed cases with the powder and projectile removed are used.

What is different about the updated assembly?

The new design has a physically lighter trigger, sear, and striker assembly with the addition of a mechanical disconnector.

Will this affect the X-series P320s?

Yes. However, the X-series flat trigger will not be replaced.

What about my CAL-X Kits?

You should send any and all P320 slides with your shipment, as the striker(s) will be replaced, and the slide(s) will need the disconnector cut. You should also include the grip module for subcompact models as these need to be replaced as part of the upgrade as well.

Does this affect the MHS pistol?

No, the MHS pistol is a different variant of the P320 platform. It has passed the US Army’s testing protocols (TOP).

What are my next steps?

There are four options based upon what type of consumer you are:

  1. U.S. Domestic Consumer Program.
  2. U.S. Commercial Dealers. For additional support, please contact Dealer Services Department, M-F, 8:30am – 5pm EST directly at 603-610-3000, option 2.
  3. U.S. and Canadian military, law enforcement, and first responders. Canadian consumers are included in this category. For additional help, contact customer support at 603-610-3000, option 3, M-F, 8:30am – 5pm EST.
  4. If you are an international customer (including Puerto Rico), please contact your Global Defense Sales representative or local distributor.

Is there a charge to participate in this upgrade?

No. The upgrade is being offered to our consumers at no cost.

Will SIG SAUER cover the shipping both ways?


What if I don’t want to upgrade the trigger assembly on my P320?

This is a voluntary service, as the P320 meets and exceeds all ANSI/SAAMI, NIJ, DOJ, California, Massachusetts, and safety standards. Sig Sauer welcomes all of its P320 owners to take advantage of this program.

What if I have incorporated aftermarket items into my P320?


Is SIG SAUER still shipping the pistol without the enhanced trigger system?

No. The functional enhancements have been made for all current and future P320 shipments.

What is the turnaround time to receive my upgraded P320?

For the US Commercial market, once your P320 is received at Sig Sauer, turnaround time will be approximately 3-4 weeks. Transit times may vary depending on your geographic location and receipt of your returned pistol.

Can I have the work performed at my local dealer instead?

No. This work must be done at the SIG SAUER factory.

What serial number ranges are affected?

Please visit our Voluntary Upgrade page and enter your serial number to determine if your serial number is affected.


Am I required to send the entire pistol?


How will I know if the P320 has the upgraded trigger system without disassembling?

The most obvious external difference is the lightweight trigger. It has a thinner profile than the standard curved trigger. The other changes are minimal and would likely not be noticed.

How often has the incident described occurred?

Minimal reported drop-related P320 incidents have occurred in the US commercial and law enforcement markets, with hundreds of thousands of guns delivered to date. These instances occurred in conditions that appear to be outside of normal testing protocols. The current P320 design meets and exceeds all US safety standards. As it relates to the ad hoc media drop tests, these were not part of standardized testing protocols, and they were performed using firearms in unknown conditions.

Should I conduct my own test to determine if my pistol is safe?

NO. SIG SAUER DOES NOT RECOMMEND THAT ANY CONSUMER PERFORM DROP TESTING BEFORE OR AFTER THIS UPGRADE. Mechanical safeties are designed to augment, not replace safe handling practices. Careless and improper handling of any firearm can result in unintentional discharge. Be aware that ad hoc testing is occurring and individuals are testing guns in conditions outside accepted testing protocols. ALL STANDARDIZED DROP TESTING IS DONE IN CONTROLLED ENVIRONMENTS WITHOUT USING LIVE AMMUNITION.

Can I return my P320 with the SIG SAUER flat trigger installed?

Yes, the pistol can be returned with any factory trigger components.

What if I have installed an aftermarket trigger but don’t have my original SIG SAUER components?

Please remove your aftermarket trigger components and send back your pistol without a trigger.

Will my Apex or Gray Guns trigger still work after the upgraded parts are installed?

SIG SAUER can only guarantee the function and safety of original and upgraded SIG SAUER trigger components. Any questions regarding aftermarket components should be directed toward the aftermarket manufacturer.

Are P320 models with an existing external manual safety eligible for the upgrade?


If I have a P320 without an external manual safety, will one be installed as part of the upgrade?

No, this is not part of the upgrade.

Is there any change being performed on the grip modules?

There is no change to the grip module for full size, compact, and carry variants. The changes are only in the metal receiver frame and the slide. The one exception is any subcompact variant. Subcompact versions of pistol will be returned with a new grip module that has a beavertail design in line with the other 320 sizes in order to effectively take advantage of the upgraded components.

Do I need to send in the extra grip modules from my Caliber Exchange Kit(s)?

Not for the full size, compact or carry kits. Only the upper components are required so we can update and test fire using the CALX kit (slide, barrel, recoil spring, and guide rod). However, subcompact kits should come back with the grip module so we can swap it out.

I have an RX model. Do I need to remove my Romeo before returning the pistol?


If the slide is milled for disconnect clearance, how will that area be refinished?

The slide is made of stainless steel so we will not be refinishing that small area. It is no different than hammer ramps on the bottom of the slide that get polished or wear. The exposed metal has no issue with corrosion.

If I send my P320 in for something other than this upgrade, will the upgrade be performed automatically?

No, the upgrade will only be performed if you elect to be part of the Voluntary Upgrade Program.

Will I be able to track the progress of my P320 when it is at your location or will you notify me with updates throughout the process?

You will be able to track the arrival of your P320 at SIG SAUER by checking the tracking number on the prepaid shipping label provided by SIG SAUER. From there, the next communication you will receive is return tracking information once your pistol is shipped back to you.

Is there an expiration date for the P320 Upgrade program?