Gun Review: Sig Sauer P-320

Sig has certainly jumped forward of other companies in the polymer gun market. With it’s modular design the 320 can be configured to fit just about any shooter at a reasonable cost. When looking through the Sig Pro Shop you see one wall with a lot of different frames from compact to full size as well as assorted grip sizes. The price runs $59.00 for a bare frame. It’s worth noting that grips from the 250 will work with the 320.

Related: SIG P320 Selected as new US Army Handgun.


When the owner purchases a new component it’s very simple to remove the internal chassis and mount it in the new frame. The same goes for the slide and caliber. Choose your caliber, purchase the slide and barrel put it on your frame and you essentially have a new pistol. The cost varies but to change calibers the average cost will run approx. $350.00 which is still less expensive than purchasing a new pistol. One of the better aspects of the P320 is what ATF considers to be “the” gun. The internal chassis is the gun according to ATF. The chassis is the serialized part that goes on the 4473. Simply this means when an owner buys one gun with the chassis he or she is able to purchase any combination of parts without dealing with additional paperwork.

This is your gun!

This is your gun!

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The Sig Academy provided us with full size P-320’s in 9mm which we carried for half the day as we went through various drills on the academy ranges.


Caliber 9mm, .40 S&W
Action Type Striker Fired DAO
Trigger Pull DA 5.5 – 7.5 lbs
Trigger Pull SA NA
Overall Length 8.0 in / 203 mm
Overall Height 5.5 in / 140 mm
Overall Width 1.4 in / 35.5 mm
Barrel Length 4.7 in / 119 mm
Sight Radius 6.6 in / 168 mm
Weight w/Mag 29.4 oz / 833 g
Mag Capacity 9mm 17 Rounds, .40 S&W 14 Rounds
Sights SIGLITE® Night Sights
Grips Interchangeable Polymer
Frame Finish Stainless Insert
Slide Finish Nitron®
Accessory Rail Yes
Features Quick and safe take-down with no tools or trigger manipulation required, Double-Action striker fire operating system, SIGLITE® Night Sights. Comes with 2 magazines.
MSRP $669.00-$713.00
CA Compliant No
MA Compliant No

The P-320 is an easy pistol to carry all day weighing in at just less than 30 ounces. The pistol overall is very smooth with no sharp edges. I did find that the grips were a bit slick after some time on the range. The standard size grip felt very comfortable in my hand, but sweaty hands can be problematic however. After being on the range for a good while in the summer heat the grip is a little slippery. Of course there are many companies that specialize in stripling Glocks and M&Ps so there’s no reason why the same treatment wouldn’t work on the P-320.

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As with all Sigs the shooters hand sits fairly low from the barrel centerline. I found the P-320 to have a higher grip and fits somewhere between a Glock and M&P in comparison. The grip angle is just about perfect and I found the 320 to be a natural pointer.

As far as accuracy the P-320 excels. I was actually rather surprised since I’ve become rather used to polymer pistols capable of good combat accuracy but nothing you would want to use for precision shots. Not so with the Sig. This pistol is very accurate.


The trigger pull is very good (5.5 pounds) and is far better than any other polymer striker fired pistol I’ve shot. Its only rival would be the M&P with the full APEX aftermarket trigger setup. Speaking of the trigger it doesn’t have the appearance of the usual polymer pistol trigger. The trigger has no center trigger safety. It’s a standard trigger smoothly finished. I understand from our conversations a Glock like trigger will be an option in the future.


There’s really nothing about this Sig I would change with the exception of a more aggressive grip finish and a manual safety. I don’t consider the lack of a manual safety to be a deal breaker however.

The P-320 is a polymer pistol worth checking out and one I enjoyed shooting a good deal. I can promise you should the search for a new military handgun goes forward you’ll see the Sig P-320 right in the competition.

Phil White

Retired police officer with 30 years of service. Firearms instructor and SRU team member. I still instruct with local agencies. My daily carry pistol is the tried and true 1911. I’m the Associate Editor and moderator at TFB. I really enjoy answering readers questions and comments. We can all learn from each other about our favorite hobby!


  • fmonk

    Maybe post a video that isn’t private?

  • Andy

    Why is the bore axis so high on this? I’m sure they were trying to cut costs by salvaging the P250, but the high bore axis was not something that needed to be carried over.

    Also, having to replace entire lower frames isn’t something I would call “modular.” Take a page from the P30.

    • The lower is indeed a modular part. The entire part is polymer that the chassis fits into. The only reason to change would be to make your pistol a compact or some other size than what you have.

    • If you check the video I think you’ll see the bore axis isn’t as high as the photos may look. My hand sits pretty high.

    • 360_AD

      The P226 also has a high bore axis and getting accurate shot placement is never an issue with it.

      • Paladin

        Bore axis doesn’t affect accuracy, it increases muzzle flip, slowing down follow-up shots. The ideal handgun would have a barrel directly in line with the shooters wrist, thereby eliminating any muzzle flip. The Russians actually made a competition pistol with this configuration.

        • Cymond

          And don’t forget the Italian Mateba MTR-8 revolver.

          • Paladin

            The Mateba revolvers have low bore axis, but not MTs 3-1 low. The designer Mikhail Margolin, who was blind BTW, flipped the action upside down to put the barrel perfectly in line with the shooters wrist. The Russians used these in the Melbourne Olympics, and they were subsequently banned for being too good.

          • Alexey

            MTs 3-1’s designer was Petr Sheptarskiy. His design was based on Margolin’s pistol.

          • Paladin

            Huh, I guess you learn something new every day. I had heard it was a Margolin.

          • mig1nc

            Oh, I want one! Looks as low as the Chiappa Rhino. Which I also want.

          • Cymond

            Same designer, Emilio Ghisoni

      • Sulaco

        Actually it is for a lot of shooters. The standard SIG high bore axis means the pistols always feel top heavy and clumsy (exception is their 1911 clone) at least to me and I know I am not alone on the range when I discuss this with other shooters.

    • richard scalzo

      You don’t replace the “lower frame”. The grip module changes and that’s less than $50.00.

  • USMC03Vet

    I’m thinking of replacing my German 2022 with a p320. That trigger/firing group makes the gun look like an absolute dream to clean. Wish I could get one of these on the range to try out.

    No barrel change between .357 sig and .40?

    • We didn’t clean them but I would think it would be super easy. Remove the chassis and spray it down,wipe it off and lube then place it back in the frame. Shouldn’t be much to it.
      I think most people will like it. I really like the trigger pull. Short take up and reset. It’s worth a rental if you have a range like that in your area.

      • 360_AD

        I owned a P250 and cleaning was exactly as you said. For the P250 Sig offered caliber exchange kits. I imagine they’d do the same for the 320 eventually.

  • FourString

    Might be useful for Cali when SSE expires by the end of the year. I.e. import serialized part, add modular components over time even after SSE expires. Or even get the Cali post-SSE microstamped version and replace with out of state parts?

    • Cymond

      But without SSE, how will people in California get it in the first place? The only way would be PPT from people bringing them with them when they move into the state, and interfamiliar transfers from out-of-state parents or children.

      • FourString

        Yes, I meant if you got one in by the end of the year :T

      • Steve_7

        What do you mean by “interfamiliar” transfers? Interstate transfers of handguns are prohibited, period, except through FFLs. Or by bequest, which means you have to die first.

        • Cymond

          I’m addressing the issue of the California “roster of handguns” that are the only handguns permitted to be sold (or transferred) in the state. There is an exception to the roster for gifts from direct bloodline relatives – parents & children. Hence, I cannot buy any pistol that is not on the roster, but my mother on the east-coast can give me an off-roster pistol as a gift. Yes, it must still go to a FFL in CA, but it is no longer bound by the roster.
          One of the other exemptions to the roster is a sale between 2 private parties who are both California residents (which STILL goes through a FFL, 10-day wait, registration). The advantage is that if someone has an old pistol, they can still sell it. I can’t buy a Luger from a gun shop, but I can buy one from my neighbor or someone on the internet. Also, people can bring off-roster pistols when they move to CA, assuming the pistol is legal. I brought a STI Spartan 9mm with me when I moved to California and registered it with the DOJ using a special form.

          • Steve_7

            I was going to say, even if the State of California allows it, the Abramski case makes it clear you can’t do it anyway, it would be a straw purchase. But anyway, gazing into my crystal ball…. I see… the State of California removing that exemption too.

    • jess

      it would have to be a complete pistol. it would be the same as trying to DROS a bare frame, which we also can’t.

      • FourString

        bloody hell. didn’t know that about the frame. even non serialized? jesus

  • nomad

    Wish I had known about “bore axis” sooner, so I would had something else to worry about.

  • That grip angle is very steep. Not sure I would enjoy that. By the way, what is the angle, 7*?

    • I haven’t seen an actual measurement but nothing over 9 possibly 10. It certainly cures the extreme angle of the Glock which bothers me to no end.

  • James

    Is it small handed-friendly? Meaning, how short is the trigger reach?

    • Not very long but again you can adjust that.

      • James

        Thank you for the reply, but would you please be able to elaborate more? What exactly is the trigger reach from the backstrap? Is it shorter or longer than, say, Glock 19 trigger reach? What about SIG P226 or Beretta 92FS?
        Also, how is the trigger reach adjusted in P320? Thanks!

        • Similar in pull to a Glock but a much better feel. Less pull and reset than a 226 and way less than a 92FS. Sig doesn’t list the exact figures and our handling was on the range so we had no way to take measurements. Adjustment is by choosing the frame size that works best for you and changing it out.

  • 1leggeddog

    that is a NICE looking pistol!

  • Bill

    There ought to be the equivalent of Godwin’s Law for “SIG” and “high bore axis.” A SIG may not be your preference, but if a person has difficulty shooting a full size service pistol in 9mm because of illusory problems caused by the height of the bore above their hands, the problem lies with them, not the pistol.

  • mig1nc

    I handled one of these at my LGS. For the money, I preferred the grip and trigger on my PPQ and the HK VP9 is obviously a winner as well. Frankly, i just really did not like the grip at all.

  • Dan-O

    Tried fondled pistol at a LGS, the balance was okay, feel was acceptable, trigger was meh. I’ll pass in favor of HK’s VP9.

  • Lee

    I’m still waiting for Sig to jump on the striker fire band wagon. Maybe start from scratch rather than trying to make a “price point” product no one really wanted to begin with. The P320 looks to be just another rehash of the P250 with their new fancy CZ P07 slide swoop cut someone figured out how to program in the CNC. Sig makes a good gun, but they can’t make a good cheap gun. Like the P250 the P320 will be the gun thats easy to sell, but a week later the customer is trying to return it, even though you have an all sales are final sign posted about the register… Seriously, I get less problems with customers buying Taurus products.. They actually expect something from the Sig.

    • BigFED

      I know I’m late in this response, but trust me the P320 is NOT a “rehash” of the P250!!! Best I can compare it to is the Para LDA.

      • Lee

        So what exactly is different?

        Sig has a hard market spot to try to make with the P320. They aren’t exactly filling a vacuum. They have a strong customer base with their traditional P-series design, but typically they are trying to catch up. The trend continues away from the SA/DA design to the simple striker fired guns. I’d say a day late and a dollar short in general though.

        Right now they are competing against Glock, S&W, Springfield (the top three sellers of striker fire guns), along with other companies now producing like Walther, Caracal, HK, and a few others trying to make their name in the striker fire duty capable world. The NSSF puts out great market data, along with the USPSA and IDPA in their annuals.

        My analogy, I see it like competing against walmart in the retail industry. What do you have to offer they don’t already? In a duty handgun, your typically competing against Glock which still maintains a bulk or the market, with S&W not far behind with their M&P.

        So what is Sig offering? Better quality? Better reliability? Improved Ergonomics? Better price? Better Accuracy? Higher Capacity? A solid market reputation? Aftermarket parts availability? Something special no one else has? So far the answer is NOPE… so where will they fill the roll in the market place? Solely their name? I look back to the 250. Even it it didn’t have the quality control issues, its still facing the same problems. Not saying its not a good gun. But I don’t see it making it on the currently flooded marketplace.

        I think Sig did great with their 1911 type. That was the smartest thing they ever did. I see a few of their X5 and X6 series floating around, but its more of a european IPSC market gun, competing agains Sphinx and Tanfoglio. Their classic P-220, 226, 228, 229’s will always have a novelty market in the US. I think the P320 was a bad investment and will show a loss. My bet, in five to seven years, it will no longer be in production.

  • Steve_7

    It looks pretty sensible, has a push button magazine release instead of a stupid paddle, has a proper takedown lever instead of some stupid tab or pin. Has forward cocking serrations which is a good idea too. Has metal sights. I might actually buy one, haven’t bought a new handgun for a long time. Only thing I’m not too sure about is the grip, looks a bit S&W Sigma-ish to me. If it feels slick with 9mm, .40 is not going to be much fun.

  • BigFED

    Go ahead and start your flame throwers, but I have a P320 and it has become my EDC and I have a very extensive of handgun makes and calibers that I can choose from. I may not be in the competitive league of many/most commenters here, but I have been shooting for over 60 years, carrying with credentials/permits for over 50 years and have had one or three “serious social discussions” AKA “street level competitions” so I feel somewhat qualified to comment. Oh, yes I also worked for a range where we assisted LEOs in training and qualifying. From that I have also gained perspectives from the LEOs on the front line.

    Point 1, not ONE of those that have been in a “serious social discussion” worried about trigger reset during the event!

    Point 2, not ONE of those that have been in a “serious social discussion” worried about high bore axis during the event!

    Point 3, not ONE of those that have been in a “serious social discussion” worried about ANYTHING other than GETTING lead on target during the event!!!

    Over the 50+ years I have been “in the business”, I have found two types of shooters. Those that CAN SHOOT no matter how bad the gun, and those that CAN’T SHOOT no matter how good the gun!!! Almost everything else is, as my school teachers taught me, an EXCUSE, NOT a reason!!!

    • raz-0

      Look, when competition shooters talk about high bore axis, you are talking about people who are spending gobs of money, ammo, and time improving fractions of a second. Ergonomics are a real and genuine issue. There’s a reason certain formats of gun don’t succeed in those circles. It’s not made up.

      On the other hand, that doesn’t mean things that don’t fit that need best are worthless. Sigs used to be quite nice. These days, I’m seeing enough folks with QC issues on their brand new guns that it would concern me in general. Showing up my first day to a USPSA match? Hell yeah shoot a sig or whatever you got, it won’t make that much difference until you get better. Drag it to the match 10 years and 500-1000 matches later? Not unless it is just for grins.

      Also, IMO sigs historically get a lot of crap about what isn’t ergonomically beneficial about them because a lot of it has been very well executed until more recent QC issues. I know a lot of competitors who like them in general, but they simply can’t shoot as fast and accurate with them as with some other guns. It might only be a fraction of a second, but all else being equal that fraction of a second wins.

      • BigFED

        Won’t argue against anything you said, but my viewpoint is at the street level for LEO, CHL/CCW, everyday folks that legally carry, not those “high speed, low drag” operators. As I said, the ONLY competition shooting that counts is at street level. Personally, I carried a 1911A1 as a Federal Game Warden starting 1962 LONG before they were popular in LEO agencies. I then carried my personal Colt 1911 commercial grade for years with my Federal agency and as a reserve for a city PD and two county Sheriff Offices that gave me waivers since I usually was in the top two or three during qualifications. Was I that good? NO, the others were that bad!!! I practiced, they didn’t.

        RE: SIG quality. In working on guns for over 50 years, I don’t think I can name ANY brand that I didn’t have come in for a repair, including my own personal ones. Had to send a P229 back to have the take down lever fixed (they wanted to “see the gun”) for why it may have broke. I am/was certified armorer for several MFGs including Glock and SIG. Carried a Glock 23 from 1990 after I came back from Europe. Migrated to SIGs about 2007, DAKs mostly, with a SAO thrown in. Now retired, carry my P320 or P938.

        Do seconds count? Yes, even fractions of a second, but stop watches are irrelevant on the street. Nothing that happens on the street EVER goes according to plan. EVERYTHING changes. All those “shoot house” practices or range qualifications don’t prepare you WHAT to DO, they teach you HOW to shoot!!! No alibis or mulligans on the street!

        One other thing, IMO. There are probably VERY few active LEOs, whether on SWAT/Tactical or street that could come ANYWHERE near competing with the Rob Latham’s and other top folks that shoot for the money, trophies and titles.

        • raz-0

          Generally agreed. USPSA and the like are good at teaching gun handling. they don’t teach you much of anything regarding tactics, and certainly not team tactics in any way shape or form.

          As for guns break. As a competition shooter, yeah you can wear those suckers out. My concern with SIG is what I have seen arriving out of the box lately and the rate at which the frequency you see some of the stuff slipping past QC is increasing, which isn’t a good thing.

          • BigFED

            You are right on recent SIG quality. Personally, I think SIG is trying to be everything to everyone! Just looking at the list of models and then the variations within a model. Seriously, 18 versions of the P238, 25 of the P226, 24 of the P220, 27 of the P1911, 9 of the P250 of all models and 11 of the P290, NOT COUNTING caliber options!!! There is NO way to try and provide that wide a variety of “custom” guns and maintain quality. All the options for, sights, grip panels, two-tone, SAS, non-SAS, etc. Do that many folks want to brag “Hey, I have a one of P290?”

            When I bought my first Colt 1911 Government Model it was available in blue or nickel, best I remember. Working at the AAMU (Fort Benning) at the time, the Head Armorer offered to put a “duty tune” on it. I still have that pistol, the only changes since have been Armaloy and Millet sights. Still shoots EXACTLY where I aim it! That was what I was carrying in my “serious social discussions”.

  • Why do you insist on doing “new” reviews of guns that have been on the market from six months to more than a year? When you presented an announcement – not a review – of Magnum Research’s MR9 clone of the Walther P99, I assumed it was a new offering. Wrong! There were YouTube videos on it from 2013.

    The same goes here for the P320. Unless the reader checks the date of the article, they will assume the gun has just recently the market instead of a late review of one that has been out there for awhile.

    As far as new gun reviews go, have significant errors in them is irresponsible – the longer the gun has been in the hands of users, the less of an excuse there is to not get the review right.

    First of all, like its P250 brother, the only difference between the two is that a striker-fired control unit replaced the hammer-fired control unit. Like the P250, the P320 DOES NOT HAVE an ambidextrerous slide CATCH lever. The lever only catches on a squared notch on the left side of the gun. On the right side, the lever pokes through a wide arch (4mm wider than the squared notch) cut into the slide that does nothing to hold the slide back. It’s sole purpose is to disengage the catch on the left side – which holds the slide back by its “chinny-chin-chin” (less than 2mm of contact between the slide and the release lever). A gentle tug on the slide in a rearward direction drops the release lever like a trap door on a gallows. So, the most you can say is that it has an “ambidexterous slide RELEASE” for left-handed shooters that is most useful in a gravity-free environment.

    The safety on the Sig P250 was its God awful trigger designed by Tomás de Torquemada of the Spanish Inqisition. Actually, Torquemadais a good namefor it because it torqued my finger every time I shot it as it would not break until it was literally touching the back of the trigger guard. The pull on the trigger was akin to using a handgrip exercizer as it got progressively harder to pull the further back it went, so by the time the trigger tripped the sear, my finger was trapped inside the guard and was torqued counterclockwise by the muzzle flip.

    The only way to work the trigger without getting my finger twisted was to use only my finger tip throughout. Not the way they teach you to use a revolver-like full double action only trigger.

    So, the P320 got rid of that non-cockeing hammer from Hell and replaced it with a striker that can be cocked and allowing for a soter, less heavy trigger. But to say the following is mind-blowing:

    “The trigger…is far better than any other polymer striker fired pistol I’ve shot. Its only rival would be the M&P with the full APEX aftermarket trigger setup.”

    Pick up a Walther PPX and try that trigger. Besides being half the price of the P320, the PPX also has a non-bladed trigger, and a rated pull of 5.5lbs, but it feels like a 3lb pull when you use it. And its a pre-cocked hammer wth no striker, and it’s the PPX that beats the triggers on every other poly pistol in its ease and consistency of use – except for its striker-fired brother, the PPQ M2, that retained the long levered, easy-to-use, TRUE AMBIDEXTEROUS SLIDE CATCH, that was on the PPQ M1 – a combination of the PPX’s slide with the body of a P99, which also had a bladed trigger.

    Unfortunately for the PPX, the lack of any external safety IS a deal-breaker because its light trigger and wide trigger guard makes it too easy for it to be inadvertendly tripped and the gun discharged. If it had a bladed safety, grip safety, decocker (like the P99), or even a manual safety, it would be the best thing since sliced bread.

    Of course, adding a plain trigger is cheaper than adding a split or bladed trigger, you don’t have to be a gunsmith to know why they went with the plain trigger.

    One last trigger comment: the articulated triggers on the regular M&P’s don’t even belong in the conversation. They feel and operate like crap. I want a trigger that, when it breaks, it’s crisp, clean, and one you can both feel and hear. The diving board that S&W uses for its M&P is none of the above.

    I don’t buy a gun and then drop more money on it just to make the trigger operate as it should have out of the box. I sell the gun and take that money to buy to a better gun.

    The removable FCU is also problematic in that it does not sit consistently in the frame. Every reviewer has struggled when turning the takedown lever to remove the slide (the lever looks and operates the same as on the PPX, but since the PPX FCU is meant to stay in the frame, it does not have this problem). The reason for the struggle is that there are four holes with zero tolerance which must be perfectly aligned to replace the pin: two on either side of the frame and two on either side of the FCU.

    I had a soitujation wqhere I could not replace the pin because the holes did not align when I replaced the FCU. Sig Sauer service sucks as I spoke with two different reps and sent both annotated photos and a video explaining the problem and neither one replied back.

    I finally traced the problem to some poly shavings that were keeping the back end of the FCU from being seated in the groove (or platform) put into the frame for it. It was just enough to through off the perfect hole alignment. The first time I go t the P250 and tried to turn the takedown lever, it would not turn. AT ALL. I had to take a pliers to it, to turn it.

    This happened twice, and after cleaning out the back of the frame and liberally lubing the takedown pin with Tetra gun grease, it turned like it was on ball-bearings.

    I bought this gun because it was rated a “Hall of Fame” pistol by the NutnFancy project.

    It’s a “Hall of Fame pistol” with a “Hall of Shame” trigger.

    Finally, saying that a gun is less than 30 ounces is a euphemism for not saying it weighs 29+ ounces when the max weight on other poly’s averages 27 ounces.

  • onamo

    I know the VP9 did well in Alex C’s limp wrist test, I’d be interested in seeing how the P320 performs under the same conditions.