Throwback Thursday: The SIG P320 Striker Fired 9mm Handgun

By Wilburn Roberts published on in Firearms

The SIG P320 strikes a familiar outline. The P320 is an adaption of the P250 to a striker-fired mechanism. The frame, magazine and barrel are the same as the P250.

Picture shows a black SIG Sauer P320 9mm pistol.

The SIG P320’s most interesting feature is its versatility and changeability.

The P320 is a modular design. You may change the grip frame and slide around the serialized metal chassis as well as exchange the grip frame for larger or smaller units. Institutional users can keep a few sets in stock to fit all hand sizes. The rest of us will be careful when we order.

P320 Features

  • The test gun came with the medium grip, full-size frame, which seems to suit most shooters across the board.
  • The SIG weighs 29.5 ounces (unloaded) and has good balance.
  • The slide has a Nitron finish and features forward cocking serrations, which offer sufficient purchase for manipulation.
  • The controls include a slide lock, magazine release and take down lever.
  • The SIG magazine release is a trapezoid shape. I had the impression of pressing forward as well as in with this release. It is a good feature of the P320.
  • Field strip is simple enough, using a takedown lever. The pistol does not have to be decocked for disassembly, a plus.
  • The grip frame is pebbled on the front strap, back strap and each side in the same pattern. It worked well for the author and other shooters.
  • Magazine capacity is 17 rounds. There are grooves in the handle to allow a strong grasp on the magazine in the event of a stuck magazine—which isn’t likely to occur.
  • Trigger compression is consistent at 7.75 pounds. While classed as a double-action only trigger, it behaves more like a single-action trigger. The more you use this trigger, the more you appreciate it. You can accomplish good shooting with this action.
  • The sights are steel in the popular 3-dot white outline design. The SIG sights are dovetailed in place both front and rear.
  • Two magazines accompany the SIG along with a plastic range holster.

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Part of the firing evaluation was accomplished with Fiocchi’s reliable and affordable 115-grain FMJ load. I drew the P320 and fired at man-sized targets at five, seven and 10 yards.

  • The pistol came on target quickly.
  • Fast recovery was the rule.
  • Trigger compression is short and reset fast.
  • Trigger travel is about .4 inch.
  • There were no failures to feed, chamber, fire, or eject.
  • The SIG P320 is comfortable to fire.
  • In combat drills, the SIG P320 made a good showing.
  • In absolute accuracy, the pistol exhibited an average of two to three inches in accuracy with different loads.


Like all quality handguns, the SIG prefers one load to the other at long range, when firing for absolute accuracy. However, at seven yards the pistol put all of the rounds in the magazine into one hole.

At 15 yards, a bit longer than the average engagement range, the SIG P320 put five rounds of practically any service load into a two-inch group.

I was able to test fire the SIG extensively. I moved to a heavyweight load preferred by many shooters.

SIG Sauer P320 pistol right

Cheap does not have to mean rock bottom. SIG Sauers are not normally associated with “cheap.” However, by comparison, the SIG P320 is significantly cheaper than previous models and still features SIG’s “To Hell and Back” reliability.

  • The Fiocchi 147-grain Extrema proved accurate, reliable and with less felt recoil than the 115-grain load. This loading penetrates deeply and expands modestly.
  • I also used the Winchester 115-grain JHP in the Personal Defense line. Affordable but effective, this loading is fast enough to ensure expansion.
  • I also fired a quantity of the Winchester 115-grain Silvertip, a proven defense loading.

All loads were reliable and gave good accuracy.

SIG modified the basic design of the hammer-fired SIG P250 in the SIG P320. In my estimation, the new pistol exhibits a faster lock time, a smoother trigger action and greater practical accuracy.

The P320 is light enough while offering service grade accuracy. For those preferring ease of maintenance, a simple operating mechanism, and SIG reliability in worst-case scenarios the P320 is an excellent choice.

The SIG P320 is a solid handgun, reliable, accurate and rugged enough for duty. The reserve of ammunition is good and the pistol will handle most emergencies in trained hands.

Do you have a SIG P320? Do you agree with the author’s review? Why, or why not? Share in the comment section.


Bob Campbell is a former peace officer and published author with over 40 years combined shooting and police and security experience. Bob holds a degree in Criminal Justice. Bob is the author of the books, The Handgun in Personal Defense, Holsters for Combat and Concealed Carry, The 1911 Automatic Pistol, The Gun Digest Book of Personal Protection and Home Defense, The Shooter’s Guide to the 1911, The Hunter and the Hunted, and The Complete Illustrated Manual of Handgun Skills. His latest book is Dealing with the Great Ammo Shortage. He is also a regular contributor to Gun Tests, American Gunsmith, Small Arms Review, Gun Digest, Concealed Carry Magazine, Knife World, Women and Guns, Handloader and other publications. Bob is well-known for his firearm testing.

View all articles by Bob Campbell

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Comments (23)

  • Brian


    I fell in love with these when someone offered me one to shoot while they serviced my P229. Amazing fit, comfort, accuracy, and a smart looking pistol too. I’ve since bought two and have zero regrets.


  • Kevin


    I, too, have owned many handguns over the years, including Sig, HK, Beretta, FN, Glock, Walther, and Magnum Research. Sig Sauer has continued to offer top designs, engineering, quality, and reliability. I own several Sigs, and my P320 full-size 9mm is my favorite. Great look, striker-fired, excellent quality, balance, reliability, and accuracy, and 17+1, with 21 round mags available. Top gun.


  • Isaac Rascon


    I own this sig p320 and as said in article the strong point is the modularity,i bought the compact,and then later bought the full size conversion kit. But for some reason i cant shoot this gun with ease of accuracy like my Canik TP9 sf Keep in mind the Canik was only 339 dollars.So i guess more expensive isnt always better. I think its because of how comfortable the Canik and slimline it is it fits the hand better,translating into better shootng.


  • Blankovich


    I own and shoot many brands and types of hand guns. 1911’s, Glocks, M&P’s, Sigs, some wheel guns. I got the P320 soon after its introduction. From the first time I took it out of the box, chamber checked it and did some dry firing, I was impressed. No, it doesn’t have a good 1911 trigger; but what does? Yes, its trigger is, in my personal experience the best production striker fired trigger FOR ME. Your mileage may vary.

    I now have the original full sized, medium grip 9mm and a compact, medium grip 9mm that I carry every day. The P320 carries on Sig’s reputation for designing and building super tough and reliable weapons. I am as accurate as I can expect to be in self defense drills.

    Glock popularized the “plastic” gun. Sig has nearly perfected it. I say ‘nearly’ only because I don’t think much on this earth is perfect.

    If you are in the market for a good carry gun I would take a long look at the P320.

    The last thing I wanted to say about this product is that it’s grip is, without a doubt, the most comfortable I have every held and shot over long periods of time/rounds. Luckily, I have medium hands and the standard frame fits me very well. The grip width is neither too wide nor too slim. It’s just right. With the ability order a frame for under $50 nearly everyone can have a pistol that is ultra-reliable, accurate and affordable. I never thought I would see a Sig Sauer product that I would say was affordable!


    • Dragon


      That term “affordable” with regard to SIG Sauer firearms brings to mind another pretty nice piece. A few years back, I purchased a new P250 Compact model in .357SIG for the price of $365.00. I liked the P250, because as I have commented elsewhere, I tend to favor hammer guns for everyday carry. Then, I decided that I wanted a 9x19mm P250 for my bug-out bag as a compliment to my SIG P320. I managed to get the 9mm model at a gun show for $400.00, and I was also delighted to find that the appropriate caliber magazines are interchangeable between the P320 and the P250. Finally, I found a subcompact P250, which is a very handy sized pistol for wear around the house, and I purchased it for $369.99. While high end SIG pieces are delightful to own, there are…..there REALLY are…..some very reasonably priced SIGs out there.


    • Andrew Szekely


      Do you know if the Sig Sauer 320C-9-BSS (compact) support a modular optical site (red dot), or do you have to purchase a new slide w/rail like the 320RX?


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