Throwback Thursday: The SIG P320 Striker Fired 9mm Handgun

SIG Sauer P320 pistol right

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.

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.


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.

  • 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.


About the Author:

Wilburn Roberts

When Wilburn Roberts was a young peace officer, he adopted his present pen name at the suggestion of his chief, as some of the brass was leery of what he might write. This was also adopted out of respect for families of both victims and criminals. The pen name is the same and the man remains an outspoken proponent of using enough gun for the job.

He has been on the hit list of a well-known hate group, traveled in a dozen countries and written on many subjects, including investigating hate crimes and adopting the patrol carbine. He graduated second in his class with a degree in Police Science. It took him 20 years to work himself from Lieutenant to Sergeant and he calls it as he sees it.
The Mission of Cheaper Than Dirt!'s blog, The Shooter's Log, is to provide information—not opinions—to our customers and the shooting community. We want you, our readers, to be able to make informed decisions. The information provided here does not represent the views of Cheaper Than Dirt!

Comments (23)

  1. 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.

  2. 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.

  3. 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.

  4. 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!

    1. 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.

    2. 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?

  5. I have 3 Sigs, including the P250 and I like them all. However, none of them are what I would call perfect. The one I like the least is my Sig P229. Extremely well built gun and it has never failed me, but the grip just doesn’t fit my hand well. A spectacular and well built gun, but just not to my liking for one reason and one reason only. I just dont shoot it very well due to the grip. That being said, this is just another gun review without one negative, something that could be changed/improved, or something the author just didn’t care for personally. Just like how I dont like my P229 grip. Something as small as that is important because most likely there are going to be a bunch of other people out there that might not like the grip either and just might influence their decision when it comes time to buy. There has to be something that isn’t perfect about the P320 and I am sure there are a lot of people out there that want to know. So I hope you are picking up what I am laying down here.

    1. Yes, Eric…..You have a valid point. It is interesting, that my most often carried pistol is a SIG P229 with DAK trigger, and as you say… is a fine quality piece of weaponry. ‘Fact is, I like it so much that I purchased a police surplus P229 with the same trigger system as a spare. I tricked both of them out with XS Big Dot express night sights, Lasermax guide rod lasers, and Hogue G-10 grips. I also understand your criticism of the P229 with regard to the grip feeling right in your hand, since I have the same criticism of any and all Glock pistols. My preference in carry pieces runs to pistols with hammers, rather than strikers. I know to some it may seem irrational, but I feel safer with a gun whose hammer I can see to verify it’s state of readiness and safety, over one whose striker is not visible…..but that’s just me.

  6. I have a SIG P320 Compact, and generally it’s OK. I purchased it mainly, because I have many SIG pistols, and I was curious about their entry into the striker fired market. One of the neat things I discovered about the P320, though, is that it and the P250 use the same magazines, and since I also have a couple of P250s, I was overjoyed to find that I can stash magazines (of the same caliber) that will function in both pistols…..except compact magazines will be too short if one tries them in a full sized model.

  7. Since WHEN is the 115 grain Winchester Silvertip a “proven defense” loading? This is the 9mm bullet architecture that FAILED to incapacitate in the Miami shootout that cost the lives of two FBI agents!
    Has Winchester changed the design??
    I would NEVER use the Silvertip as carry load.

  8. I have the P320 9mm carry and I love it. The trigger has just a small takeup, crisp break and a short reset. To me, the trigger is far superior to the stock Glock triggers. The spec is 5.5 to 7.5 lbs, mine appears to be right at 6 lbs.

    The only complaint I have is the the slide lock lever is small. I would love one just a bit easier to manipulate. Sixty six year old fingers don’t seem to work as well as they used to 🙂

    I will be in the process of redoing most of my handgun collection and switching to the P320 series…nice to have the same trigger on three different frame sizes and all the different calibers that will be offered.

  9. As to the Sig Sauer P320 – –
    * Can you get the P320 in a two-tone finish such as desert tan & black?
    * Can you get the P320 in a cal. other than 9mm?

    1. Totally concur. I love my P320 Compact. My trigger feels as smooth and crisp as the 3.5 lb triggers I had on match .45s back on the Marine Corps Shooting Team years ago. When I went shopping for a new pistol, I’m glad they were out of Glocks.

    2. Yes, they come in 9mm, 357Sig, .40 & .45. You can buy separate grips and slides to mix colors to your desire.

  10. Just wanted to share my recent sig 1911-C-3 purchase.The gun is everything I wanted and more.I can’t believe how easily it holds it position on rapid fire and the lighter trigger pressure on second shots on.It’s truly a beautiful piece of craftsmanship and I’m glad I spent more going to the sig.Only trouble I am finding is getting correct accessories for it,not to mention the cost of the .45 cal. ruger target .22 cal. Ammo.Chuck in NY

  11. I have been shooting handguns for 50+ years, including one trial with the fabled SIG-Neuhausen P210, and the new P320 full-size is THE most effortlessly accurate handgun I’ve ever fired. Trigger and ‘reset’ are EXCELLENT. I’ve heard folks ‘complain’ about the bore axis being so high over the grip- I urge these people to FIRE ONE before making this claim. It instinctively points beautifully and it can run its whole magazine through a single slightly-more-than-9mm hole at anything out to 25 yards. EXCELLENT pistol!!!

  12. I received my 320 for Christmas ran about 500 rounds through it no problems at all I really like it. I wish Sig would have come out with the exchange kits when they came out with the gun. Also I got the same gun you tested. I want the .9mm sub compact no idea when it will be released. That is the only neg. about this gun. I have the 250 too I like the 320 better

  13. I have a new 320, .40cal full medium and I need extra mags for duty, can I buy them from sig. Nobody else has any. can you tell me where and who may have them. Greensboro, N.C.

    1. I have a P320 carry in 9mm. I purchased extra magazines from top gun supply on-line. They have quite a large inventory of magazines in many calibers. Prices are OK but not cheap but that is what I have come to expect for new pistols. I love this pistol but not sure what ‘size’ the grip is. I would like one size smaller and plan to contact Sig. Grip is excellent for a polymer pistol but I still prefer Talon rubberized grip. My trigger causes a little pain in the very tip of my fingers and I have not figured out how to correct this. I may see if I can replace it with a polymer trigger similar to the Springfield XDs I carry. I had a Sig P226 in the service and the metal trigger in that pistol did not cause the same pain.

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