Check out the SIG P320: https://www.sigsauer.com/CatalogProductDetails/p320-full.aspx
Buy one on GunsAmerica: /SIG p320
When the SIG SAUER P320 was introduced, it was met with cautious optimism. After all, the P250 platform that first introduced the polymer framed, modular component concept at SIG didn’t exactly set the world on fire. But then few innovations really do take off on their first flight. The Wright brothers made several piles of scrap in their field before making history. The P320 is a striker-fired, rather than hammer-fired platform that uses an internal chassis or fire control group as the serialized gun (SIG calls this the “frame” to make things really confusing) – everything else is just “parts” and not a firearm. If this is all old news to you, then you’ve seen it before. The P320 series has been out for a while now – about a year. But not in .45 ACP – until now. Initially expected in the early spring of 2015, it has been slow in coming for those of us who love the P320 and love 230 grain projectiles.
I do admit without shame that I am a fan of the Sig Sauer P320. The consistency of the platform is very impressive, as is the ability to quickly re-purpose your firearm from a subcompact 9mm to a full sized .40 or .357 Sig in mere seconds. It’s like Transformers for gun geeks! But I remember thinking, as I lifted the first 9mm P320 that I fired, “boy, I really wish this was a .45!”. I don’t know why it is, among many gun-folk, that a handgun somehow becomes more legitimized when offered in .45 ACP. But as long as I’m confessing, I will also admit that I buy into it too.[full_width]
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One reason .45 ACP is not a mix-and-match with other calibers is the magazine size, and magwell difference.
Modularity and Compatibility
And then there is the issue of compatibility with other P320’s. It’s not. So let’s start right off with the disappointing part. By compatible I mean the ability to remove the chassis from a .45 and insert it into the kit (grip frame, side, barrel, etc.) of a 9mm, .40 S&W, or .357 Sig. With no official information that I could find, I was left scratching my head as to why that might be – and more importantly, why Sig would devalue the product line that way. After all, the pressures of the .40 and .357 are greater than the .45… so maybe it was a cartridge diameter issue.
The first thing I did when I got the P320 .45 on my work bench was pull a 9mm version apart and try mixing parts. Everything looks promising at first – but they do not interchange. The reasons, as I’m able to observe, are two: First and foremost it is a magazine size issue. 9mm, .40 S&W, and .357 Sig can all fit into a magazine of identical box dimensions. The .45 ACP cannot. The box of the .45 magazine is both wider and deeper to accommodate the bulky cartridge, and therefore requires a specially molded grip module. Reason two is the ejector.
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The other reason is the ejector size and geometry, which is unique for the .45. A preventative tab is present on the smaller calibers to prevent use with .45 Auto.
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The only functional difference I could see between the smaller caliber chassis and the .45 chassis is the fact that the latter uses a shorter ejector. Not surprising, once I realized it. I have no doubt that there would be malfunctions if that were not so. The chassis for non-.45 calibers also includes a metal tab to prevent the .45 magazine from being loaded in. For all intents and purposes then, the .45 Auto variety of the P320 family stands alone. There is still the good news that you can eventually have several sizes (four, if they follow the Full, Compact, Carry, and Subcompact offerings) in .45 ACP that use just one serialized chassis.
Like its smaller caliber siblings, the P320 .45 comes with two magazines and a convenient (and actually quite good) polymer paddle holster. The full sized magazine for the full sized grip panel (what we would call the ‘frame’ of any other pistol) holds 10 rounds. This puts it on par with the majority of .45 autos, but comes up short of several models offered by Glock, Springfield Armory, and others. Never is the “Size vs. Capacity” argument so relevant as with the massive .45 Auto cartridge. I don’t mind 10+1 and I think it allows for a “just right” sized pistol stock.
Grip frames are a replaceable commodity with the P320. This is the full size, medium grip. With five grooves of picatinny rail out front and E2 style texture, it provides a stable base for the gun.
My copy of the P320 came equipped with the optional SIGLITE® night sights. The standard sights are 3-dot contrast. That is the only optional choice with the P320 line, except for some marketing driven color options for the grip modules such as flat dark earth (FDE). Night sights raise the price of the gun, but the various color offerings generally do not. Fit and finish is typical Sig Sauer. In other words, excellent. One may be tempted to poo-poo the look and feel of the dull poly lower on these guns, but remember – Sig does not consider these a permanent part of your firearm and replacements are $46 as of this writing.
That said, the design of the grip module is fantastic from an ergonomics and practical perspective. The look is pure Sig, and your hand feels right at home wrapped around it. The grips are available in three hand sizes for each module size for each caliber. Scratching your head yet? Okay, it works like this: For each caliber offered, the P320 is (or will be) available in Full size, Compact, Carry, and Subcompact. Then, each of those sizes can be had in small, medium, or large. That’s twelve permutations of each caliber P320! And that’s not considering the fancy colors like FDE. Essentially, the S,M,L sizing changes only the circumference and reach aspects of the grip surface, making them thinner or thicker in the handle. The length and height don’t change. Each grip module has molded-in grip texture that is very akin to the modern E2 style grips on newer Sig pistols. I like this texture and find it very effective.
The trigger on the P320s is pure SIG SAUER. No compromises here.
What made me fall in love with the P320 though, was the trigger. I was pleased to see that Sig did not follow the crowd when it comes to striker-fired triggers, but instead made the P320’s bang switch out of steel and left it smooth faced and thick. It has a Sig shape and feel. But most of all what it has is an incredibly crisp break and reset. I was hoping that the .45 version would be just as good as the 9mm and .40 that I’m accustomed to. Sig specs the trigger pull at between 5.5 and 7.5 lbs. My measured average tipped the scale at just under 7 lbs. But I have often opined that the weight of the trigger is far less important to a good shooting experience than the cleanness of travel and crispness of break. And because both those elements are superb on the P320, the feel of the trigger is much lighter than those numbers suggest.
Sig Sauer supplies the P320 pistols with two magazines and a polymer paddle holster. Before you scoff at the “free holster”, I’ll tell you that it’s a pretty good one. Of course it fits your new Sig perfectly, and it’s sturdy and very practical. I’d be happy to wear it out before I felt the need for a new one – even if this were to be a competition gun. The magazines hold 10 rounds, and are manufactured by Mec-Gar in Italy. They functioned flawlessly in all my testing – as did the pistol. Not a single malfunction of any kind after nearly a half-case of Remington UMC, some Winchester, Federal, Freedom Munitions, and steel cased Tul Ammo. I even fed it a whole box of my handloads for good measure. Everything feeds, fires, and ejects without a hitch.
Sig Sauer P320 .45 ACP Fullsize
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The P320/.45 was put through its paces with several types of ammo.
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| 25 Yard Results – Rested | |||
| Ammunition Brand | Ammunition Type | 5-Shot Group | 3-Shot Group |
| Winchester White Box | 230 gr. FMJ | 2.382 | 1.050 |
| Remington UMC | 230 gr. FMJ | 2.319 | 0.978 |
| Federal American Eagle | 230 gr. FMJ | 4.535 | 1.997 |
| Freedom Munitions | 230 gr. FMJ | 4.113 | 2.082 |
| TulAmmo | 230 gr. FMJ | 4.264 | 1.660 |
I did some 25-yard accuracy tests, rested on a bag. The results were good overall, with a pretty wide spread between best and worst. The P320 seemed to like the Remington UMC the best, followed closely by Winchester white box.
Looks like we’ve got a blue collar gun here that likes to shoot what you can find at the local discount store. I shot five-shot groups, and then from those I also chose a “Best Three” subgroup. The best performance was a three shot group from Remington at just under 1 inch.
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Just edging out the Winchester, the best groups were achieved with Remington UMC 230 grain ball.
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The SIG SAUER P320 takes its design inspiration from the X-Five line, making it one sharp looking handgun.
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Most P320s ship with the Medium sized grip module, but are available in Large and Small too.
Form and Function
If you like Sigs, you’ll find the feel of this gun in your hand to be a familiar one. Yet, though both are double-stack .45’s, it is thinner than the Sig Sauer P227 because it is a one-piece molded grip body that needn’t be any larger than necessary. On this molded grip, Sig has placed texturing very nearly identical to the E2 grips on their new handguns. I like this texture and feel it does a great job of providing superior grip without the discomfort of some more aggressive styles. You’ll understand just how good that grip texture is, when you see the skin embedded in it after a shooting session. I hear it’s great for removing callouses, too. The beavertail on the P320 full sized frame is a generous one. It gives the web of the hand a comfortable and secure place to wedge itself and aids in the stability of the pistol during recoil. Opposite that is a nicely undercut trigger guard. My smallish hands find the reach to the trigger to be just about ideal with the medium module (which is the most common one shipped for stock orders).
The author’s only pet peeve with the P320 is the over-sized takedown lever.
Controls are sparse, well placed, and function very well. The slide stop/release levers appear on both sides of the pistol for all P320’s. It’s not as high quality as you may be accustomed to on a Sig, but it’s part of the removable chassis and had to be designed for universal fit. Easy to reach without altering one’s grip, it operates just fine. The triangular and aggressively grooved magazine release is one of the best I’ve used. The button is large and easy to depress. You don’t feel like there is an automobile suspension spring behind it. Magazine ejection is clean, fast, and very positive. The control is reversible for lefties. The only remaining control you’ll find out the outside of the pistol is the one that bugs me. It’s the takedown lever, and in my opinion it is far too large – mainly in the thickness department. It adds about 1/8” to the thickness of the pistol. Not a big deal maybe on the full sized frame – but a very big deal on a subcompact. The takedown lever is part of the serialized chassis – and moves with it from module to module if you buy kits. It also interferes with the thumbs forward shooting grip – sitting right where your thumb wants to be. Sure, I can move my thumb under it, and I do (or it takes a beating), but I have to think about it every time I grip the pistol. Maybe there is an engineering reason for the mass of this lever, but if not I would like to see that thing put on a serious diet. Someone at Sig needs to talk to someone at Springfield Armory – they’ve got this figured out.
The trigger guard is square and large with serrations on its flat front for those who use that as a finger-hold. The magazine fits flush to the grip frame and does not protrude on any side. There is a tabbed area on either side of the grip to allow grabbing and assisting the magazine’s exit, should that ever be necessary. The grip is finished off with a lanyard ring at the heel.
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Magazine fit is perfection. Perfectly flush on every side with finger tabs in the unlikely event that assisted removal is necessary.
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The Gun Parts
The important parts of the P320, aside from the removable chassis (or FCU) are all up top. The slide is stainless steel coated with Sig’s impervious Nitron® finish. The 4.7” barrel is typical Sig Sauer and its coating is nearly impossible to mar or scratch with normal use. It sits atop a dual captured recoil spring and guide rod assembly made of steel. A nicely milled and polished breech face and short external extractor finish it off. Taking its design cues from the X-Five series of pistols, the side presents a ruggedly beautiful aesthetic, with its geometric angles and cuts, and large forward serrations.
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Every field strip can easily be a detail strip by removing the FCU. It adds only seconds to the process and allows you to inspect and clean every part.
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The entire line of P320’s is just a year old, and the .45 ACP is still so new that Sig Sauer still lists it as “coming soon” on their website. How it will fare over the long haul is still a question to be answered. Whether or not LE agencies will adopt it as a duty gun or full service platform remains to be seen. But as I said up front, I’m a fan of the design concept and I think can become a proven warrior. Where I think Sig stands to hurt itself with the P320 line is in the accessories and kits department. Exchange kits are still hard to obtain, and Sig has recently raised the price of them significantly (about one third!). If you cannot get a grip module or caliber conversion you want, or have to pay nearly the price of a whole new pistol for it, there isn’t a lot of value in the concept. Let’s hope that they find a price point that works for them and us – and that they fill the shelves soon.
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Removable serialized chassis/frame/FCU = gun (top). Gun-shaped polymer parts and slide assembly – not a gun.
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Tritium powered SIGLITE ® night sights are optional, but are among the best factory-installed night sights because they also provide great daytime visibility.
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The trigger might measure a tad on the heavy side, but it’s so smooth and crisp that you won’t believe the numbers.
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It’s nice to see that full-sized bore on a full-sized gun!
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The author got almost all of these 20 rounds in one ragged hole at 10 yards offhand.
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The included paddle holster is not just ‘okay’, it’s quite good.
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I just bought the P320C. I love this gun. I put 50 rounds of 45 ACP down the pipe with not one problem. Straight from the gun store to the range. The Night sights are also very good. And this gun is accurate. If there was a problem? I am guessing they fixed it.Or I got a good one. Either way I am one happy retired Army Staff Sergeant. And I would recommend this gun to anyone looking for a good striker fired 45. this is just my 02 on the gun.
I got my new Sig P320 45 a few months ago. The first day firing was not one I found enjoyable – many jams and second guessing myself in that purchase.
I took it home, thouroughly cleaned it, found a few minor tips that I sanded to soften the edge and went back in the next day.
I had three different brands of ammo and found that one brand in particular seemed to jam, while the other two did not at all.
I switched to just those two brands and had zero jams. I have been shooting now 2-3 times per week and have found that the jamming has ceased and can even shoot the 1st ammo that seemed to have the most jams – with maybe 1 out of every 50 of that brand needing a slight tap to the back of the slide to set all the way in prior to firing, with still not a single jam with the other two types of ammo.
I think with the 45 there might be a slight break in period that I never had with my Sig 9mm, and now the 45 is my absolute favorite, most dependable, and most accurate gun to shoot!
Why isn’t there any comments on the 40S&W P320, isn’t it any good??
Mostly because 40s&w is starting to die out. Since it lost its credibility with law enforcement and feds and such
Over my 30 years in the Army I have fired about every hand gun know to man and after my retirement in 2006 I was one of the first to purchase the new Army’s SIG p320 .45 auto. I cannot begin to tell you how disappointed I was with this weapon.
Brand new weapon, never been fired, american .45 factory ammo, weapon clean and oiled and the first round JAM. Pull back the upper receiver clear the JAM and fired the weapon for the second time JAM. The first 9 rounds fired were all JAMS. I dissembled the weapon at the range and found witness marks on the sides and top of the barrel and on the sides of the receiver that indicated the barrel had contacted the sides of the receiver and was getting PINCHED between the two sided of the upper receiver.
Not a good way to start a relationship.
With the potential of the weapon firing when dropped and now the JAMMING problems I had with this weapon, this would not be my GO TO weapon of choice. If you are looking for this weapon for home or personal protection you might want to rethink your options.
Col. John P. Gonsalves (retired)
Does anyone know if the manual safety from the 9mm guns can be refitted to the 45 FCU?
I have the compact 9mm, and the sub-compact grip mod. For the size of my hand, either is a perfect fit and performs flawlessly. The sub compact with ten round magazine is easily concealed in a shoulder holster, and fits with no noticeable bulge under my leathers. I got it purposely to be a cc. weapon, and for that duty it is well designed and feels comfortable for me. It is my first Sig, and I got it because most of my public safety buddies carry Sig Sauer as their duty weapon, and none of them has ever had a misfire from one, that sold me.
Just got my first sig, the 320 full size. For me it shot great at 10 and 15 yards…had a tough time getting the 10th round in mag though anybody else agree? Thx.
Justin, is the .45 available in the compact version? Thank you. Jay Andre
Clarification on the 320 and if it can be converted back and fourth from a 45 to a 9mm. I just took a few classes at the Sig Sauer Academy and fell in love with the 320 after firing it at their facility. I had the same questions about converting and I was told directly from the rep at the pro-shop on the Sig Sauer campus that yet it can, with a catch. You must purchase a 320 chambered in 45 first and then you can purchase any of the conversion kits available to convert it (say to 9mm). You can’t do this the other way around. I purchased a P320C chambered in 45 and plan to convert it to 9mm (full size). I hope this helps as I am sure that the dealers may not have this information and to get the most bang for your buck (options speaking) purchase the 45 first and then convert.
Thank you! Thank you! We’ve been looking at this and have a P320 .45 compact on “special order,” and although it’s clear you can’t buy the 9 mm and change up to the .45, my son could think of no reason it wouldn’t work the other way around. Yours is the first comment I’ve seen anywhere that specifies this – so if we ever get our .45, we should be able to buy the 9 mm conversion kit for it.
If you buy the 45 and plan on converting it to 9, you’re also going to need to buy a grip module for 9 and magazines for 9. When you tally up the cost, you might as well just buy a new 9mm gun. The grip and the mags for the 45 will not work with the 9mm conversion kit unless you buy mags and a grip for 9. I’m pretty sure that the FCU for the 45 is different slightlytoo so you might want to look into that before you buy a conversion kit.
I am a Sig armorer myself, but took the trainings before the 320 came out. I assumed the .45 fcu would work with an ejector change. Can you clarify if the ejector from the .45 fcu needs to be replaced with an ejector from the 9mm fcu?
I own and shoot various Sig, and other brand handguns. I like Sig my P220 Scorpion Carry, a commander sized 19911a1, is flawless. I love my p938. No malfunctions, ever. My P250c 9mm, no problems. The .45 acp conversion kit I bought for it, runs good, never a problem. My only gripe is the tiny slide stop levers. Hard to manipulate.
Thanks for the great review. I bought a p320 45 but have been wanting a 9mm, I thought I would be able to just swap the chassis. You saved me a lot of time, money, and headache.
Is the chamber on the 320 fully supported . Are hand loads approved.
First I confess that I am a big Sig fan. Although I own a variety of other makes–Colt, S&W, Ruger, Glock, Para Ordinance, Dan Wesson, Springfield Armory and others–I own a large number of Sig pistols. P220, P245, P226, P228, P250, P290RS, 1911-22, C3 (Commander sized. 45 1911), and now the P320 Carry in .357 Sig.
I am retired from the Army, where I spent several years as a weapons instructor, and spent 5 years as a civilian peace officer. We still carried the 1911 in the Army and I loved it. As a cop I frequently carried a .357 magnum and developed a lot of respect for the caliber’s performance. The .357 Sig is a close match to the venerable old magnum. However, I’m not a caliber bigot and my small Sig collection reflects that, including .22, 9mm, .40S&W, .357 Sig and .45acp.
The P250 was a revelation to me, allowing me to mix and match the 9mm, .40S&W, .357 Sig and .45acp. I like the P250 series and knew from the first rumors of the P320 that I would have to have one.
I lucked out and purchased a new P320 Carry chambered for .357 Sig, with night sights, for $539. The fit and finish, the quality of workmanship, the lack of tool marks, etc., are equal to or exceed that of pistols costing three times as much.
The pistol performs like a champ at the range, too. I have fired just over 700 rounds through it at distances from 3 feet to 50 yards, using a variety of ammo brands and weights and quality. Although I got best results with Hornady XTP, I experienced no hiccups, no failure to feed or eject, no malfunction of any sort with any ammo. At distances up to 25 yards, the pistol shoots small groups as long as I do my part. At 50 yards I’m simply ringing gongs on metallic pigs, ducks and other small critters. Someone with younger eyes and steadier hands could do much better.
Anyway, this P320 Carry is now my new EDC. It’s difficult for me to bond with a polymer striker-fired pistol but Sig outdid themselves with this one. And knowing I can now switch to a .45acp with minimal cost and effort is the icing on the cake!
I’ve had my 320 for 2 months – put 500+ rounds down range — and let me tell you it’s the greatest pistol I’ve ever shot. Trigger smooth as a water slide. Accuracy like a fine sniper’s rifle. You Glock fellows need to wise up shooting a 320 is like driving a Rolls instead of a tractor.
That’s what I tell everyone too. I used to have a Glock 23 with night sites, couldn’t hit the broad side of a barn. Now with my Sig P320 compact FDE 9mm I can’t imagine a more accurate pistol. 4″ clay targets at 15 yards not a problem.
I notice on Sig’s website that there are Sm/Med/Lg grip assemblies for the 9/40/357 P320, but for the 45 P320, there are only Med and Lg listed. Does anyone know if Sig plans on releasing a Small size grip for the Full size P320 .45? Also has anyone heard any rumors about a 10mm version of the P320 and, therefore a caliber X-Change kit?
I just purchased a 320/45acp in the compact/small version last night in the FDE color with Siglite sights. Feels great in the hand. I also have a 320 sub-compact in 9mm. Taking it to the range this weekend! So they are out there.
I also just got a p320 in fde small frame they are around love it just couldn’t resist after having it in my hand haven’t shot it yet but trigger feels amazing can’t wait
I’ll bet that takedown lever is MIM and made in India like most of Sig’s other small replaceable parts.
Admittedly the break in compatibility between .45 ACP and the smaller calibers is definitely a bummer. I imagine the striker mechanism necessitates the difference, as my P250 doesn’t suffer from this. There was a drop-in part change for the slide lock when I bought my .45 ACP conversion kit (I believe it was the Compact model) included with the kit that works from .45 ACP and smaller that was suggested/required if upgrading from anything smaller than .45 ACP. Since the P250 and P320 share magazines, it seems odd that the frame on the P320 can’t handle everything from 9mm to .45. I am just assuming it’s part of the striker action that adds or repositions a component that could interfere with the two different magazine body sizes.
I like the interchangeable frame idea alot. I wish most other manufacturer did the same. Ahem!! Glock. I like the idea of changing it out once you get bored or for different duty. Have one frame for target, one for home defense. One for carry. Sounds good to me. At an msrp of that nature I would just go buy the new magnum research mr9 /mr40. Nice review though and a nice gun.
I bought a sig p320 9mm when they first came out. I took it to the range and ran 300 rounds through it. At least once in every magazine I had a failure to extract, sometimes two or three. I sent it back to sig, they returned it pretty quickly (around three weeks) with a note that said the problem was fixed. Went to range same day and now had at least two failure to extract per mag. Called sig and they told me to shoot another couple hundred rounds through it and the problem would correct itself. In the next 150 rounds, it only got worse. I took the gun back to the dealer who sold it to me and he said my gun coming back was the second of the three he had sold. I was a Glock guy when I bought the sig, now I am a Glock guy only. I sold my other two sigs.
I’d find a differentdealer if I were you. He was pprobably doing something to them or swapping parts. Could be he got a bad run before sig caught the problem. I can show you a list of guys who had similar issues with glocks. That doesn’t condemn the mug. Some bad parts are bound to get by the inspection process no matter who the mfg is.
It would seem Sig went at this backwards. If they had started with the .45, it would have been much easier to use that platform to smaller calibers instead of now having two non compatible units.
Curious, why no JHP in the ammo testing?
If you drill a hole in the bullet. It will just slow it down, air resistance.
My question is, why is it the P250 can use all calibers with same FCU but P320 can’t? Having asking that, my 250 .45 never worked very well, mostly feeding issues.
The P320 has a modified extractor on the 45 FCU that is slightly different from the rest of the P320 line.
Has Sig made the announcement about the .45 not being available as a caliber exchange kit? If so, I missed it. It’s a shame! I intended getting it to compliment my 9mm SC. I doubt I will get this .45. I would probably put a bit more in and go with the P227. Thanks for the review, Justin.
Been looking forward to this, in compact version tho..
Whoops! Before the comments come – I forgot to note the MSRP. Bonehead oversight on my part. Depending upon the option of SIGLITE night sights, list price is $628 – $713. Expect street prices to be more in the $550 – $675range.
I was able to get my hands on one in early May. I paid $569 w/ sig lite sights. It has performed flawlessly as has my 9mm P320C
Interested to see and fell the subcompact version on the .45, I’m hoping it won’t be much longer
I was able to get my hands on one in early May. I paid $569 w/ sig lite sights. It has performed flawlessly as has my 9mm P320C
Interested to see and fell the subcompact version on the .45, I’m hoping it won’t be much longer
Regarding the sizes of Sig P320 offerings – there are actually only three ‘frame sizes’.. What Sig offers as the “Carry” model is a compact slide and full-size grip frame. As another writer mentioned, Sig combined these components as a LE duty carry gun so that the overall capacity was equivalent to a full-size gun, but that the length of the gun (due to the compact slide) was more convenient to ‘carry’.