XE2-1461Being that the Sig P320 is a relatively new platform in terms of USPSA, I thought I’d post a quick FAQ about it as it relates to our sport. But in a nutshell, the Sig P320 is a modular handgun where the serialized component is not the frame, rather the Fire Control Unit, or FCU, that has isolated the components of the firing system into its own standardized module that can be moved across a multitude of components allowing for a quick transition to any other calibers and platforms and allowing endless customization. In fact, it was this customization that initially won me over to the platform.

Note, this is a living document so expect some changes and updates as things change.

Last update, 2.4.2016.

The Sig P320 FAQ


Basic Information on the Sig Sauer P320

Is it Legal to Shoot in USPSA/IDPA?

  • Yes – USPSA NROI Production Gun List
  • IPSC – Yes: IPSC Production Gun List
  • IDPA – Yes, but note that IDPA doesn’t maintain a list of approved pistols, rather a list of requirements.
    • IDPA CCP rule is barrel length of 4.1″ or less. SIG P320 Full-Size has a 4.7″ barrel. SSP legal, not CCP legal. The Carry and Compact versions with 3.9″ barrels are legal for CCP and SSP.
    • With it’s 3.6″ barrel the SIG P320 compact is IDPA BUG legal.

Sig P320 Specific Gunsmiths – This is not the definitive list by any means, but these three gunsmiths are by far, the de facto wizards of the P320

Available Sights for Competition

  • Dawson Precision has a Fixed Set for Competition that I feel is sized incorrectly at .200 tall rear and a .205 tall front. For me, it shoots far too high. I currently have a .200 rear and a .215 front that shoots about one inch high at 25 yards. I think a .220 would be perfect, but will get one and confirm. As for widths, I am currently shooting the .115 rear and the .100 front. I am having a custom set made by Dawson/Burke that will be .125 rear and .115 front with some other little touches that I prefer. More on that later.
  • Gray Guns has a sight set for the P320 that unfortunately isn’t sold, rather fitted so currently you’ll need to send your slide to him for his custom made rear (which is my favorite once produced at the moment) and a Dawson Precision fiber optic front.

CR Speed Magazine Pouches

  • Will they work? Yes, with a little work. Apparently they molds used to create the CR Speed magazine pouches and inserts were made long before the P320 existed, so none of the included inserts work out of the box. But if you use the STI/SV insert and put a shim (I use a 1/16″ flat washer) in between it and the wall of the magazine pouch it works swimmingly.

Accessories and Parts – With any new platform, it’s going to take some time for the aftermarket to ramp up once the platform has proven that it’s going to survive and there are common demands for improved/custom/desired options. For now, it’s pretty slim which is partly due to how new the gun is, but also in large part a testament to how Sig got it right.

Common Issues

  • Dead Trigger – This isn’t really an issue per se, but rather part a safety feature, the crux of it resulting in a “dead trigger” after reassembly. Once you reattach the slide you are required to lock the slide back using the slide catch. Pushing the slide catch up will release the safety disconnect inside the FCU and return the pistol to normal operation. We all do this once.
  • Pinched finger/Dirty finger – the gap in the Grip Module where the trigger exists that can allow some escaping gas to flow and/or pinch the user’s finger. To address these complaints, the latest revision of the FCU includes the “Adverse Trigger,” which essentially provides a wing on top of the trigger that fills more of the gap, as well as slightly extends the tip of the trigger.
  • Slide Not Locking Back on Empty Magazine – This is most certainly due to the position of the slide catch lever being too far rear, too big, and too wide. Many shooters, including myself, using an aggressive/high grip will inadvertently press the catch lever up enough to prevent the slide from locking back. Sig has redesigned the slide catch lever to be half the size, and extend forward as to prevent interference as well as built a “fence” around the catch lever to further shield it. For me, this part was a must have, and fixed the problem in short order. Note that Sig responded to this (as well as the larger Take Down Lever that most people hate) and now ship with the updated parts, see my post HERE. If you want the new smaller Slide Catch Lever, it can be had from Sig by calling them directly. The revised part number is 1300891-R. And if you hate the original Take Down Lever, you might as well order the new flat version, part number 1300777-R.
  • The gun prints high with the factory sights – If you’re getting factory sights, you might want to get the tall front and short rear.
  • Extraction – I don’t think this is a major issue, but I have heard of some people having issues with extraction, usually remedied with a new extractor.
  • Recoil/Muzzle Flip – This is not so much an issue as it is a misconception. Due to it’s higher bore axis, it is assumed that it will have more leverage against the shooter, thus have more muzzle flip. I myself had assumed this would be the case coming from the Glock G34 with a grip so high that I’d get the occasional slide bite. But truth be told, it has turned out not to be the case. In fact I can easily control recoil, far better than I ever could with my G34, and with much less effort with my box stock Sig. This “issue” is a non-issue, so don’t let it influence your decision.

What Parts to Have on Hand – So far, the P320 seems to be without an obvious Achille’s heel, but it’s really too soon to say. The pistol does have an inordinate amount of tiny springs, some of which are difficult to remove/install and are easily lost, so it’s a good idea to have some spares on hand in case of loss or damage. I spent a half an hour on the phone with some poor Sig sales person who helped me identify and order the parts, so I though I’d list the part SKU’s and Descriptions here for anyone needing to place an order.

  • Spring, Safety Lever, 320 – 1300673-R
  • Spring, Sear – 1300799-R
  • Spring, Striker Reset – 1300848-R
  • Spring, Safety Lock – 1300857-R
  • Spring, Striker 320 – 1300979-R
  • Spring, Trigger Bar 250, 320 – SPRING-5 – Brownells now carries this one.
  • Spring, Mag Catch, 250, 290 – SPRING-51
  • A spare extractor
  • Lucas Oil and Grease – It’s the official recommendation of Sig and Bruce Gray

Other Parts and Maintenance – Some other parts you may want to have because of revisions or wear

  • Lucas Oil and Grease
  • The revised flat Take Down Lever from Sig – 1300777-R
  • The revised smaller Slide Catch Lever from Sig – 1300891-R
  • Guide Rod and Spring – It seems that most are pitching the factory guide rod assembly and getting a new guide rod that accepts 1911 springs. Gray Guns and Springer Precision both offer one.
  • Spare extractor


  • Alma Cole has created a series of excellent videos on YouTube demonstrating how to tear down and reassemble the P320’s Fire Control Unit as well as tricks to getting the Trigger Bar Spring removed/reinstalled. Alma also offers permanent grip texturing if you are tired of slipping grip tape.
  • My competition load – 125 grain SNS RN bullet, 3.8 grains of Tite Group, CCI 500 primer, OAL is 1.1475. It averages 1023 FPS and 127 Power Factor.

Sig P320 Specific Sites

The Sig P320 FAQ
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3 thoughts on “The Sig P320 FAQ

  • January 4, 2016 at 5:07 pm

    IDPA CCP rule is barrel length of 4.1″ or less. SIG P320 Full-Size has a 4.7″ barrel. SSP legal, not CCP legal. The Carry and Compact versions with 3.9″ barrels are legal for CCP and SSP.

  • January 4, 2016 at 5:10 pm

    With it’s 3.6″ barrel the SIG P320 compact is IDPA BUG legal.

    • January 5, 2016 at 3:16 pm

      Thanks, Ken. I’ll update with your info.

Comments are closed.