SIG SAUER P320 Sub-Compact 9mm: A Review

SIG SAUER P320 Sub-Compact 9mm: A Review

SIG SAUER P320 Sub-Compact 9mm: A Review

For me, the Sig P320 series of pistols are very adaptable and great performing handguns. Before I give you my evaluation of the Sig P320 Sub-Compact 9mm pistol, I want to comment in general about the P320 series. There are 4 versions of the Sig Sauer striker-fired P320: the Full-Size, Carry, Compact, and Sub-Compact, all in 9mm Luger. There are other calibers available in .40 S&W, .357 SIG, and .45 ACP. I reviewed the Sig Sauer P320 Full-Size and Carry guns on 9/9/14 on this website. In essence, I was impressed with their adaptability, modularity, reliability, quality, and recommended them. Without a doubt in my opinion, the excellence of the Sig line is very recognizable. You should know that Sig Sauer is not paying me for my review or opinions, nor for the gun or ammo, so I am not on their payroll and sincerely want to give my objective evaluation.

Adaptability, Flexibility, & Modularity

With the P320, one single pistol can become a full-size, compact, or sub-compact handgun and each with 3 different grip sizes. With all P320 models, shooters can swap out the pistol’s barrel, frame, trigger and slide assembly to customize the gun. Sig recognized the significance of a striker-fired pistol, introduced these hammer-less guns, and they are popular primarily because of the nature of the trigger operation and modularity features. The P320 can be changed into whatever frame size, barrel, and caliber the shooter wants. Among the components needed for the P320 to complete a caliber change is a cartridge-specific magazine and the conversion kit. The backstrap does not need to be changed, since the entire polymer grip module can be easily changed for a comfortable, customizable, and solid grip if desired. The stainless steel frame rests inside the grip module, which is serialized, and they use identical, serialized, modular fire-control (trigger) groups. Other non-serialized P320 parts can be ordered and shipped direct to you without going through an FFL Dealer. With its modular grip frame and removable fire control assembly pioneered by SIG SAUER, the P320 is customizable to any hand size or duty requirement. The P320 can quickly be converted from a Full-size to a Carry pistol, etc. Slide and barrel conversions allow the P320 to change between calibers and barrel lengths as well. This unique modular design offers the shooter the ultimate in flexibility to change calibers, sizes, and fit. Small, medium, and large polymer grip modules ensure comfortable and optimal fit for the widest range of hand sizes. 

Sig Sauer P320 Sub-Compact 9mm Specifications*

Action:           Double Action Striker-Fired Semi-Auto
         9x19mm (Also available .40 S&W, .357 SIG, .45 ACP)
Capacity:       12+1 rds (Also available 10 rds, 10 rds, 6 rds); Magazine Catch repositions to either side
Grip Width:    1.06” (3 Glass-Reinforced Grip Modules in small, medium & large sizes))
Weight:          24.9 oz. with Empty Mag
Length:          6.67”
Height:           4.67”
Barrel:            3.55”
Slide:              Nitron High-Strength Stainless Steel; Front & Rear Cocking Serrations; Slide-Catch Lever functions from both sides
Frame:            One-Piece Stainless Steel Frame; Black Polymer Grip Module- Available in various sizes (Also available Flat Dark Earth & Two-Tone Flat Dark Earth Colors)
Sights:           High Contrast or SIGLITE Night Sights in Different Heights
Other:             2 Trigger Lengths- Standard & Short; Removable & Interchangeable Fire Control & Grip Modules; No tools or trigger manipulation required for Take-Down; Uses Compact 15 & Full-Size 17 mags
MSRP:            $628 (Black-Standard)

*  Weights and dimensions are approximate. Specifications subject to change without notice. Prices vary by dealer & options. 

Selected Features

The P320 Sub Compact is built with a stainless steel frame and slide and is covered in a Nitron finish for rust resistance. One interesting feature is that the trigger options include a smooth-faced or a tabbed-trigger safety, with the latter similar to Glock pistols. I prefer the smooth trigger face which for me is more comfortable to shoot, especially in an extended range session. The tabbed-trigger safety is simply an add-on feature for shooters who prefer to have a positive, tactile feel of the trigger prior to the trigger beginning engagement. The trigger tab safety does not replace or alter the striker safety’s function or design, as it is only an add-on option for the trigger. I like the P320 grip angle and comfort which give me more control, more so than with my Glocks. Also, the all-metal rails of the P320 in a solid stainless-steel frame give me greater stability and I like its metal trigger over the polymer. For all P320s, I like that the mags and holsters are interchangeable (some with the X grip adapter) and with Sig P250 models. The X grip adapter allows you to use the compact mags for 15 capacity or the 17 capacity ones. The X grip adapter is a little piece of rubber that fills the gap when youre using larger-capacity mags. With the SIG SAUER internal safety system, the P320 has no external safety or decocking lever to snag or hang up on the draw and I like that. The SIGLITE® night sights are very nice and the reversible magazine release makes the P320 completely ambidextrous. It also has an ambidextrous slide release. There are also nice front and rear cocking serrations.

Trigger and Reset

Trigger press on all P320 pistols in the line are generally weighted at 5.5 to 6.5 pounds, giving shooters a consistent trigger press. For me, the sub compact trigger is very smooth, short, and soft, is not a long press, is consistent, needs no improvement out of the box, and I can easily press it. Although I measured the sub compact trigger press with my Lyman Gauge to be between 6.0 and 6.5 pounds before I shot it, I understand that it is not necessarily the trigger weight, but the smoothness of the whole action of the trigger assembly that makes the difference. Overall, the stock trigger is very good and I believe that it is as good as the $150. kits some have put in Glocks and M&P’s, including myself. I could handle the recoil easily and it was mild for such a small concealed carry gun. With a partially pre-tensioned striker, I found the P320 to have a short, crisp trigger press with a quick, pronounced reset right out-of-the-box. I really like the reset and could clearly feel and hear it.

Internal Safety System

The P320 features a unique internal safety system, standard on all models with these features:

  • Striker Safety- Prevents the striker from releasing until the trigger is pressed
  • Disconnect Safety- Prevents the gun from firing when out of battery
  • 3-point Take-Down Disassembly Safety System- Only allows disassembly if slide is locked back, mag removed, and take-down lever is simply rotated, without pressing the trigger or using tools
  • Takedown is prohibited without removal of magazine
  • Takedown is prohibited without slide locked to the rear
  • Rotation of takedown lever allows disassembly without tools and without pressing the trigger.

Some Advantages:

  • Grip Modules (in 3 sizes)
  • Fire Control (trigger) Modules- Interchangeable
  • Night Sights; Standard Steel Sights
  • Rounded, No-Snag Trigger Guard & Edges- for concealability & comfort
  • Very Thin Width and Contoured Frame
  • Easy and Quick Disassembly
  • Nice Capacity of 12 +1 for 9mm
  • Front & Rear Slide Serrations- for easier Slide Racking
  • All Steel Guide Rod, Magazines, & Slide Rails

Range Performance

The small-size grip frame for the sub compact fit my medium-sized hand nicely, with my pinkie finger just partially dangling. However, I was able to maintain a good solid grip without adjusting my grip. I was very surprised for such a small and lightweight gun the recoil was light and easily managed. I sincerely enjoyed shooting the gun. While I only had about 100 rounds of Federal American Eagle 115 grain FMJ ammo to test it at the range, the P320 sub compact performed flawlessly and I have no doubt it will handle any modern JHP ammo just as well. It is so smooth to operate, and I really like the trigger and definitive reset point. To me, it is very comparable to my  Smith & Wesson M&P 9 Compact, especially regarding the 12 capacity and similar barrel length, although lighter in weight and shorter in total length. 

One caveat we all recognize is that ANY gun should be “broken-in” with about 300-400 rounds or so fired for a better evaluation of its performance. So recognize that I did not shoot that many rounds. Remember, the gold standard is for you to actually shoot and handle the gun and learn your accuracy with it and things about it, like I did. Let me say up front that for me for ANY gun, ACCURACY and RELIABILITY are most important. Closely related to that is the handgun’s trigger, so I focused on these features.  The 320 Sub-Compact 9mm shot extremely well and I was accurate with it in rapid fire; e.g. see below my first magazine of 12 rounds that I fired at 7 yards.

Sig P320 Sub-Compact 9mm - 12 Rounds - 1 Mag - 7 Yards - Rapid Fire

Sig P320 Sub-Compact 9mm – 12 Rounds – 1 Mag – 7 Yards – Rapid Fire


Performance & Handling Summary for Sig P320 Sub-Compact 9mm 

1. The accuracy and reliability were very good for me at close distances of 5, 7, and 10 yards. My groups were all 4.0 inches or less for the first time I ever fired the gun “out of the box” drawing from the holster it came with in the hard case. I used a Modified-Isosceles Standing Stance, a two-handed grip, and shot 115 grain FMJ. I had no malfunctions nor stoppages and could handle the recoil easily.

Sig P320 Sub-Compact 9mm in Hardcase with 2 Mags, Holster, Lock & Manual

Sig P320 Sub-Compact 9mm in Hardcase with 2 Mags, Holster, Lock & Manual

2. The trigger press out of the box averaged 6.2 pounds without modification with my Lyman Electronic Trigger Pull Gauge. For comparison out-of-the-box, my Sig 938 has a 7.1 pound press; the Springfield XDs has a 7.2; my Ruger SR9C, Glock 19, and M&P 9C all have about a 6.0 press; my Springfield EMP a 5.8; my Ruger LC9s has a 5.2 press; and my Colt XSE Commander (.45), Kimber (.45), Sig (.45), S&W Pro 1911 (9mm) and Taurus (9mm) 1911s have about a 4- 4.5 pound press each. Although I recognize that my brain is my best safety, I do not want a too light trigger for concealed carry, nor do I want a heavier one either. All of these are close to my desired range.

3. The trigger was smooth, crisp and very good. It had a short travel distance and short, identifiable reset, so I could get off quick follow-up shots easily and keep on target easier. The reset was very identifiable.

4. The striker-fired trigger made for consistent and reliable shooting with pretty much the same press each time. It was just a slightly harder press that I am accustomed to, since I mostly shoot 1911s and single actions.

5. The Siglite night sights were easily identifiable and I like them.

6. The weight of the gun was about 26 ounces with a loaded magazine in place and this is manageable for concealed carry. I like a slightly heavier gun for better recoil control, comfort, and accuracy.

7. The 9mm was just the right caliber for me for carry and I strongly prefer it, as you probably know from the reasons in my other articles. So the P320 Sub Compact met this requirement.

8. The width of the 320 SC measured 1.06 inches and this was slim and very nice for me. The grip angle was fine and it felt very comfortable in my hand, especially when shooting. To me, width is a key CC factor and this width was perfect.

9. The capacity of the 320 SC is 12+1 and this gives me mental comfort, especially when dealing with multiple bad guys and when compared to some of my other CC guns with less capacity. The mag release can be repositioned to either side for an ambidextrous advantage.

10. The height of the 320 SC was 4.67″, compared to my XD-9 SC-Mod 2 at 4.75″, my M&P-9C at 4.3 inches, my SR9C at 4.6 inches, my EMP at 4.8 inches, my Glock 19 at 5.0, my HK P30 at 5.4, and the M&P Shield at 4.6 inches. All are acceptable for concealed carry, with the smaller numbers, of course, being more advantageous.

Bottom Line

I definitely RECOMMEND this Sig Sauer P320 Sub Compact 9mm pistol for concealed carry, based on the above criteria and information. This gun will be in my concealed carry rotation among my 6 guns and will certainly be in my top 3 carry guns. My wife said this would be in her top 2 carry gun choices. It was a joy to shoot this gun and I am ready to shoot it some more. I hope this review has helped you. I will purchase this snag-free, thin, sub compact for myself. In my opinion, it is an excellent striker-fired pistol for concealed carry with its great capacity of 12 rounds, minimal recoil, acccuracy, and excellent trigger, but decide for yourself based on your desired features, the gun’s attributes, tradeoffs, and your use and needs. TRY IT BEFORE YOU BUY, like any possible handgun purchase.

Continued success!

Further information: or call 866-345-6744.

Photos by Author and Sig Sauer.

* This personal opinion article is meant for general information & educational purposes only and the author strongly recommends that you seek counsel from an attorney for legal advice and your own personal certified weapons trainer for proper guidance about shooting & using YOUR firearms, self-defense and concealed carry. It should not be relied upon as accurate for all shooters & the author assumes no responsibility for anyone’s use of the information and shall not be liable for any improper or incorrect use of the information or any damages or injuries incurred whatsoever. 

© 2015 Col Benjamin Findley. All Rights Reserved. This article may not be reprinted or reproduced in whole or in part by mechanical means, photocopying, electronic reproduction, scanning, or any other means without prior written permission. For copyright information, contact Col Ben Findley at [email protected].

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  • Ron Holland

    For a “sub-compact” this gun is not light and is not small. It’s too long, too wide and too heavy, compared to the Kahr or my older LC9. It does carry more rounds, but that is more weight yet. There is no surprise that it shoots easier than other really small 9mm guns, since the weight is more like a compact or some full-sized guns.
    This post sound like it is right out of the sales materials. There is not one single negative about this gun listed. Is it absolute perfect? It must be.
    Don’t get me wrong, I like Sigs, but starting off with the disclaimer that this is “objection” when it doesn’t seem objective at all is a bit disingenuous.
    Finally, has anyone priced this “versatility”? For some manufactures, this new idea of a modular gun that can be anything comes at about the same cost of multiple guns. Add up all the versatility options, frames, barrels, triggers, etc. and this is going to cost way too much for one gun.

    • Col Ben

      Thanks Ron. I appreciate your personal preferences, priorities, and opinions. I respect your ideas. They just mostly happen to not agree with mine. That’s OK. That does not make me right and you wrong. Nor does it make you right and me wrong. Gun selection is a very personal and private matter. My objectivity may not be your objectivity and, sadly, no one can be 100% objective or even close to it. We all have our own world of reality, expectations, priorities, etc. and we ALL don’t know what we don’t know because of our individual and different experiences, preferences, education & training, influences, what we’ve inherited, controllable and some uncontrollable & unrecognized factors by us, etc. We ALL behave in a way that makes sense to ourselves… given our delimited and very personal set of different experiences. We respond to our personal reality. That’s the way it is. I honestly stated my opinions and was not paid for them… my opinions were not out of any sales materials. They are my genuine beliefs based on my background & experiences. I empathize my positives and opinions about a gun and leave the decision for readers when they personally try the gun for themselves. For my carry gun, cost is not a major consideration for me, as it is for you as you stated and for some others. That’s OK. Give the gun a try. Thank you again for your ideas. Persevere and continued success!

  • Mike Dineen

    The bore axis to grip height looks huge compared to so many other’s in this class. I would expect that to effect shot recovery/muzzle flip, and/or recoil in some undesired way. Can the author comment on this as compared to the other pistols he is comparing the P320 to?

    • Col Ben

      Thanks Mike for your comments. A picture can be misleading & does not tell the full story. I am aware of only a small handful of handguns with a low bore axis, e.g. Italian Mateba MTR-8 revolver. I suppose the IDEAL handgun would have a barrel directly in line with the shooter’s wrist to eliminate any muzzle flip. Yes Sigs generally seem to have a higher bore axis (my 226 SAO and DA-SA do, but not an issue for me), but this new 320 sub-compact TO ME is not top heavy, not clumsy, is very accurate, and I can easily control any muzzle flip. It does not have the extra grip angle like a Glock and for me the 320 SC is very comfortable and controllable. I like its short takeup and reset. This gun will not be used in competition so the high bore axis is not a major (or significant) concern, since I don’t need to improve a fraction of a second with the competition stop watch. I really believe for the everyday-regular carry shooter this gun will be fine, as long as the proper fundamentals are regularly PRACTICED. I hope carry shooters don’t look for what will not work, but what will work and then practice the basics, to overcome their personal shooting problems. I don’t think this concern is with the pistol, but with techniques, fundamentals, and control through practice. Personal preferences and personal practice. Just my 3 cents minus one cent. Thank again Mike. Continued success!

  • Precision Guncrafters

    For the times I need to carry small & light weight, I’ll stick with my Kel-Tec P-11. It only weighs 14 oz. empty, and still holds 10 rounds of 9mm in the magazine. The original trigger pull sucks, but that is not too hard to correct. Heck, I would guess my Glock 23 weighs less than this so-called sub-compact Sig 320. Oh, either one costs a lot less than the Sig 320.

    • Col Ben

      Thanks for your opinion PG. To each his own decision. YOUR CALL! For a $300 pocket gun, the P-11 is a nice small, reliable pistol. The P-11 has a very long and heavy trigger pull (9 pounds per their website) and a very slow reset, all of which affect accuracy, so regular practice is important (like with any gun.) Mods certainly help. This standard trigger press is not acceptable to me. I like the 320s near 6 pounds. I want more capacity than the P-11 offers and like I said in the article, I prefer a somewhat heavier gun for better recoil control, comfort, & accuracy. The P-11 frame pins are plastic and someone mentioned that theirs sheared off. The P-11 sights are plastic and the same person said they tend to come loose. Yes they can be modified & fixed, but time & effort involved & you do usually get what you pay for. What price to defend your life and the lives of your loved ones? Your very personal decision, preferences, and dependent upon your goals, priorities, and available funds dedicated to self defense. Continued success!

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  • Randy

    Isn’t it funny how people that don’t do gun reviews all of a sudden become gun review, reviewers??? Jesus! Thank you for the stats and your opinion on the Sig. If anyone wants to tell us how much better their gun is than anything and everything being reviewed perhaps you should start your own blog. I am a fan of this Sig so far in the Carry Size. Grip/frame changes are about $50. Total conversion w slide and barrel seem to be around $300. This Sig WITH night sights is around $525…so the Glock is not cheaper…even with the Glock crappy sites Glocks are similar cost or more in Gen 4. And if you are trying to compare the price, reliability and performance of a Kel Tec P11…then you really don’t belong reading gun reviews…just keep betting your life on the cheapest gun you can find.

    • Col Ben

      Amen! All opinions are certainly worth something as subjective evaluations to help you form your own opinions and make your personal decisions. I understand how familiarity breeds superiority for some folks. I appreciate your comments. Continued success!

    • Lindsay754

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  • Ben: How does this compare to an XDs?

    • Col Ben

      Hi James! Recall from my Feb. 2014 XDs review that I did recommend it. I also really like this Sig, especially the 12 stnd. capacity (versus 7 for XDs) and thin grip 1.06″ & nice angle (but good.94 for XDs). Heights and weights are very similar. I shot better with the Sig 320 SC and the trigger press for it was 6.2# v. 7.2# for XDs. I enjoyed shooting the 320. For accuracy & reliability I would give a slight edge to the Sig 320. I do enjoy shooting both, but the Sig 320 SC will be in my top 3 rotation for carry. Solution: buy both. But really try the grip feel before you buy & shoot both if you can.
      Continued success James!

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  • Keith

    Sig just makes great guns. For me they fit great in my hand and have a natural point of aim. Fit and finish are superb and the tolerances on some of their firearms are on par with some customs. The Sig 320 compact has a great trigger, smooth with a short reset that is wonderful for fast follow up shots. I like the night sights, the front post is easy to pick up. I gave the 320 to my 21 year old daughter because she loved it so much. She also carries a Glock 43 but when it comes to pride in ownership she loves the 320, as she says “it’s a Sig.” I am now in the market for another. I currently am carrying a Sig .45 Ultra Compact and absolutely love going to the range with this gun. Talk about accuracy, this .45 is outstanding, much to my surprise. The 3″ barrell would lead one to believe accuracy would suffer, absolutely not the case. No issues feeding cheap or quality ammo. Once I get another 320 my rotation depending on dress and environment will be Sig 320, Sig .45, and Keltec .380. My Keltec is always with me or nearby. It is just so compact it is hard to justify not having it around. My weapon of choice is my Sig .45 Ultra, the weapon that makes sense is the Sig 320. Enjoy!