Upgrading the SIG P365: Life-Changing 12-Round Mags and A Comfy Holster

in Authors, Clay Martin, Columns, Concealed Carry/EDC

I haven’t been shy about the fact that I love the P365, enough that I bought my review gun. It is now my primary carry option and I couldn’t be happier about that. But wait, there is more! If you call now, for just shipping and handling, we will include…

Upgrading the SIG P365: Life-Changing 12-Round Mags and A Comfy Holster

What was perfect is now more perfect.

That part isn’t actually true. But one cannot really help but feel like an infomercial salesman when you have something to add to what you have already termed “the perfect carry gun.” The real story is that it is going to cost you some coins, but I think you will like the new add-ons anyway.



First up, I finally got my hands on some of the mythical 12 rounders for the P365. Given the tiny stature of the gun, 10 rounds was already pretty insane. Twelve plus one is borderline Hollywood capacity. It is so many rounds that during training my brain often forgot we still had bullets left. It feels really weird to have a little baby gun with near Glock 19 capacity.

I also like the added grip of the 12 rounder. I had no complaints about the original P365 grip, for its size it fits very well. To expect your carry gun to feel like a full-size is like expecting the sky to be purple. With my hand size, I have about half my pinky hanging off the grip, which is acceptable in 9mm. The 12 has the added benefit of being exactly long enough to give me a full grip and I would imagine many others. The little bit of added control is noticeable, and the plus 2 is amazing!

Upgrading the SIG P365: Life-Changing 12-Round Mags and A Comfy Holster

With the 10 round magazine.

I didn’t notice a difference in printing with the 12 rounder on board, so all-in-all I see it as a benefit with no downside. The only thing bad about the 12s at the moment is availability. SIG has been making them as fast as they can, but they are still hard to come by. GunMagWarehouse.com has a shipment in at a good price — $42.99 per mag. I didn’t hesitate, I picked up four while the getting is good. With the 12+1 capacity, the P365 is just one step closer to being a replacement for even a duty-sized gun.

Upgrading the SIG P365: Life-Changing 12-Round Mags and A Comfy Holster

With the 12 rounder on board.  That little bit goes a long way in terms of comfort, grip, and shootability.

The other bonus item this week is from our friends over at CrossBreed Holsters. I have been a fan of CrossBreed for years and it is my usual go-to holster for concealed carry. CrossBreed finally caught up on a design for the P365. They have several offerings now, and I decided to switch it up. Instead of the SuperTuck, my usual rig, I opted to try out the Appendix AIWB. This differs from the SuperTuck and MiniTuck not only in size but in attachment points.

SEE ALSO: P365 – SIG’s New Wonder Weapon

The Appendix only uses one clip in the front of the gun, not the usual two. Despite its name (Appendix), I have found it to be very comfortable in the regular strong side position as well. For all-day comfort, this is the one to beat. I have been using the AIWB for over a month now and it has relegated all my other P365 holsters to a shoebox down in the basement.

Upgrading the SIG P365: Life-Changing 12-Round Mags and A Comfy Holster

Crossbreed AIWB Front

The P365 has really grown on me to the point I can’t imagine carrying anything else these days. The every-growing accessory support just speaks to its popularity. Now I want SIG to create a 22-round extended magazine, you know, for when things get extra dicey.

Upgrading the SIG P365: Life-Changing 12-Round Mags and A Comfy Holster

CrossBreed AIWB holster.

For more on the P365 and 12 round mags visit SIGSauer.com.

Learn more about the AIWB holster at CrossbreedHolsters.com.

***Shop for a SIG P365 on GunsAmerica***

About the author: Clay Martin is a former Marine and Green Beret, retiring out of 3rd Special Forces Group. He is a multi-decade and -service sniper, as well as 3-Gun competitor and Master ranked shooter in USPSA Production. In addition to writing about guns, he is the author of “Last Son of The War God,” a novel about shooting people that deserve it. You can also follow him on twitter, @offthe_res or his website, Off-The-Reservation.com

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  • Beachhawk March 4, 2019, 9:29 pm

    Anyone buying this pistol will probably one or two of the 12-round magazines if they are available. The major upgrade for this pistol is the LIMA365 laser sight. With 13 rounds and a laser sight on board, you have a serious bit of firepower in a very small package. The problem is finding a good selection of holsters that will accommodate the pistol/laser combination. I like to carry IWB and I really like the click of the pistol being seated in Kydex. But finding one and finding one that is comfortable to wear is a major headache.

  • Myles Harvey January 29, 2019, 6:52 am

    This gun to me is a tea cup gun. How can they not make a 15 round mag so you can hold it. I have been told I have small hands and 1/2 of my third finger was off the tiny hand grip. If you like this gun I will take all future posts with a huge grain of salt. Sig missed the ergonomic bus with this product.

    • Paul Musatow May 5, 2019, 1:04 am

      I have been using the Sig Sauer P365 since 9-11-2018 and I just LOVE it !!! The P365 is just “PERFECT” with the 12 round Magazine. and I have NO-TROUBLE using it with either of the 10 round Mags. that came with the Handgun.

      I think You maybe have to place Your Grip a little higher in order to get Your hand in better position ??? I have Small Hands and use a Cadet Medium Golf Glove. So it just may have the Perfect sized hands for this Pistol. But, if You would go with a 15 round Magazine; I think it may Print To Much.

      If You want a Handgun with a 15 round Magazine You should go for the Glock 19X with the Smaller Slide and Larger 15 round Mag. and Frame. I do think that the Barrel for the Glock 19X is 4.02″ where as the Sig has the much Smaller 3.1″ Barrel !!! A Pistol with 15 rounds with only a 3.1″ Barrel may be out of place.

      • Jon June 16, 2019, 11:06 am

        Paul, if you are going to give someone advice about something at least know what you are talking about. The standard glock 19 has always come with a 15 round magazine, the 19X you are recommending comes with a 17 round magazine and longer grip from the glock 17 but retains the standard glock 19 barrel length. The grip length is what prints not the barrel length and anyone who has tried concealed carrying a glock 17 knows it is no easy feat to not print and I have carried a glock 19 for 10 years concealed but my P365 even with the 12 round magazine is by far much easier to conceal than the glock 19 and does not print in the slightest bit when appendix carrying and FYI Sig now has a 15 round mag for the P365

    • Dan July 7, 2019, 8:22 am

      They do! look for it

  • Mark S. January 18, 2019, 12:58 pm

    What kind of rounds are you using? I bought a 12-round magazine and I’m having issues with it. I loaded it with Liberty Civil Defense rounds. With a round already in the chamber, the 12 round mag will not go all the way into the grip, so no 12+1. I replaced the rounds with Hornady. I was able to force the magazine in with a round in the chamber, but when I racked it, it ejected the chambered round but the slide wouldn’t go all the way forward. The magazine handles 11+1, no issues. I was wondering if anyone else had similar issues.

    • Paul Musatow May 5, 2019, 8:26 am

      I had the same problem with My 12 round Magazine full of Liberty Civil Defense Rounds Loaded in 12+1 !!! The “PROBLEM” is that Sig Sauer’s 12 Round Magazines come with a VERY STIFF MAGAZINE SPRING. I had to leave My 12 rd. Mag. Fully Loaded for 3 weeks before it got soft enough for Me to use 12 rounds instead of 11 rounds with one in the Chamber.

      Just give it TIME and it will Work-Out. I even called SIG. and was told the same thing that I just told You. My Mag. Spring came Very Stiff was Twisted Badly. I wanted to send it back to SIG SAUER but, called instead.
      I hope You have the same Good results that I did ??? Bye – Paul

      • CHRIS SHELTON September 14, 2019, 8:36 pm

        I left my 12 rounder loaded to 23 for a week, solved that problem

        • CHRIS SHELTON September 14, 2019, 8:38 pm

          I meant 13

  • Michael Reeves June 22, 2018, 7:22 pm

    Loved the P365 very accurate until I shot about 60 rounds trigger quit resetting I had no trigger at all on the way back to sig I hope this is not normal and I’m not sure I will ever trust it

  • DrDollar June 3, 2018, 9:05 pm

    Now if only Sig or some aftermarket manufacturer would make an extended magazine for the subcompact P320. You can buy an adapter that slides over a 15 round magazine, but then you have a full-size grip which defeats the purpose of carrying a subcompact firearm. Sig makes an extended mag for every other subcompact its sells, as do all of the competing gun companies for their subs, so why not for the P320 subcompact? What jerks!

  • Mike June 3, 2018, 8:10 pm

    I am very disappointed that the article says the crossbreed holster is good. Crossbreed actually copied a Tucker Gunleather holster years ago to get started and bought many good reviews to get where they are today. The metal connections on the back rust, the kydex cracks very easily, blah, blah, blah.

    It has proven to me that the GunsAmerica articles can be bought, because a special forces guy should know these are trash.

    There are many other holsters that are much nicer in the same price range.

    • Mark January 8, 2019, 6:43 pm

      Not true. I own nine Crossbreed Holsters and have carried one everyday for the last 13 years. Never any rust, cracking, or any failure of any kind. I have a stack of holsters I tried prior to Crossbreed and have never looked back. When you have to be with something for 10-12 hours a day (on your body) you find what works. They get worked in and you actually forget you are wearing.

      +1 for Crossbreed – Actual customer

  • Scott June 2, 2018, 3:23 am

    Clay, I have had and carried a KelTec P11 for nearly a decade. It is no bigger or heavier than the P365, has 12+1 capacity, costs about a third (mags are about half the cost compared to the SIG’s), chews through any and all 9 milli I feed it, and predates the P365 by about twenty years. I even got a .40 kit for it (9+1 capacity in 40 Short & Weak). Now bear in mind the trigger is horrible, and with the 40 kit swapped in, function and accuracy are still fine although the entire shooting experience feeling is really, really bad, but what am I missing here? Why is everyone acting like the P365 is some never before seen type of firearm? Is it that incredible? How has the P11 been under the radar for two plus decades? Please opine. Scott

    • Chris A June 5, 2018, 8:47 am

      The gun is actually a pleasure to shoot. I was running a sccy cpx2 before. Because of size, weight, and capacity the sccy was sweet. But now the p365 has come in with all the same things but with more options. The sights are awesome, the gun handles much better than most small guns, and added capacity with the 12 rounder. Worth every penny in my mind!

      • Scott June 7, 2018, 2:31 am

        Well the P11 and the SCCY CPX2 seem very similar….. I will purchase a P365 to see how it shoots for me. Thank you for sharing. Scott

      • Scott August 27, 2018, 6:11 am

        I just bought a P365 to compare to my P11 and I must say the P365 is vastly superior. Wow. SIG engineered an awesome pistol here. The P11 and I go way back (twenty years?) but the trigger and sites don’t even come close when comparing to the P365. I had always been impressed with the P11 and its 12 plus 1 capacity and the small size, but the SIG is hands down better in every way except cost (and capacity, both having available 12 round mags). Even though it is twice as much as the KelTec (and probably the SCCY’s) the P365 is well worth the investment. The trigger difference alone is worth the extra money. It shoots so sweet that it is just amazing.

  • Amado leon June 2, 2018, 1:34 am

    Won’t trust it with my life now too many issues they getting as bad as the automobile industry what is there excuse now

  • Amado leon June 2, 2018, 1:25 am

    Like everything new You by today junk

  • Frank P June 1, 2018, 8:35 pm

    Like the looks of the holster but hate kydex. The couple I’ve used on duty and CCW guns have wrecked the finish. I’d jump on this one if it were all leather. That said, kind of funny how a good article/review on the accessories turned into a gun bashing for some of the contributors. I did a little quick research after finding a great price locally, and before actually picking it up. Based on what I found, Sig did suspend production briefly to address some problems, but resumed shipping around May 15 after addressing those issues. Don’t know about the firing pin issue but the info I found indicated that the “new” guns ship with Xray sights in lieu of the Siglites, and a new/improved recoil spring assembly. Long & short, I bought the gun yesterday and have put close to 300 rounds thru it in two range sessions. Used any 9mm ammo I could find save +p+ and handloads. Just love it and it has become my EDC overnight. This thing shoots, and there’s no shortage of ammo on board. I had no failures of any kind. It’s the same size as my other EDC, a Kimber Solo DC, and I think I shoot it a bit better. I don’t know how Sig did it, but there’s got to be some unicorn horn in there somewhere. I’m glad I didn’t listen to the naysayers before buying it. Thanks Clay, great review!

  • Beachhawk June 1, 2018, 7:29 pm

    These accessories appear to be good ideas for a pistol that no gun dealer has for sale! I’ll consider the pistol when it’s actually available for sale. Until then, I’m just not interested in the accessories.

    • S.H. Blannelberry June 2, 2018, 6:51 am

      They’re listed for sale on GunsAmerica.com! All local sales are free!

  • Jon June 1, 2018, 1:07 pm

    I have fired about 1800 rounds through mine. I have had no problems at all. The gun is very accurate. The only thing I had to do is round off the back cprners of the magazine and the grip to prevent digging into my hand.

  • Jon Shaver June 1, 2018, 9:23 am

    Bought my 365 a month ago. As of this date, have 1100 rounds of +p through. Zero Ftf/fte. No trigger problems. No strike problem. No evidence of undue wear. Very accurate pistol. No hesitation to carry or to depend on it. I take the internet rangers info u set advisement but validate with real world experience—my own and my colleagues. So far, I have no direct knowledge of malperformance.

    Just one person’s info, fwiw.

    I’m with Clay on this one.

  • jim88 June 1, 2018, 8:26 am

    $42.99 per mag ???? / $172 for four mags ……… REALLY ?

    THERE’S THE GOT’CHA

  • David June 1, 2018, 7:58 am

    I had a Magazine holder from Magholder.com for my Sig p229 that surprisingly fits the p365 magazine, a great addition to the rig, since digging for those small magazines on the pocket can be a bit tedious, now I carry one on the belt for quick access and one on the pocket for a total of 33 rounds.

    • Barry Parks June 1, 2018, 8:55 am

      You are absolutely sure the 229 functions in the 365? You have tested this your self at the range?

      • Barry Parks June 1, 2018, 8:57 am

        Sorry misread. You were talking about the pouch.

        • David June 1, 2018, 12:25 pm

          No worries. Yes Sir, I am talking about the magazine holder, fit the p365 good but I added a small piece of the Velcro tape inside, for a tighter fitting but you can go without it.

      • Paul zoba June 1, 2018, 9:11 am

        Read his post again, he didn’t say 229 mags function in a 365.

  • Infidel762X51 June 1, 2018, 7:42 am

    The best upgrade is to trade it for a SIG 250 so you have a hammer. Friends don’t let friends carry striker fired pistols.

    • Rocky June 1, 2018, 8:45 am

      Why not? Because you still live in 1981?? Friends don’t let friends think that second strike capability is a viable self-defense measure for a primary malfunction. And friends don’t let friends think that a hammer somehow makes their pistol safer or more reliable.

      • Infidel762X51 June 1, 2018, 8:56 am

        I had 2 striker pistols both junk. And the glocks I tried have triggers that remind me of squeezing a wet sponge.

      • Infidel762X51 June 1, 2018, 9:04 am

        The Army is already having trouble with their striker fired P320s and they have only been issued for a few months. Plus a recall for drop fire. And a 3 gun shooter I know dumped his because of trigger problems. SIG makes probably the best handguns in the world, except for the 320.

        • Dennis June 1, 2018, 11:29 am

          This pistol is not a P320, it’s a P365 and it’s fabulous! Try one out before you knock it.

        • Paul June 1, 2018, 2:04 pm

          It was a voluntary recall …which I did and it was really painless. Both of my 320 run perfectly and are deadly accurate pistols. Comparing 320 triggers to Glock triggers is apples to lemons …nothing alike. Any gun is unsafe when handled in an unsafe manor. As for the 365 …I haven’t touched one yet …but my 320 sub-compact is pretty small and light. It holds 12+1 all the time and can do my 15+1 mags with a little adapter …can’t see jumping to the 365. Might get the wife one.

          • Chris October 5, 2018, 7:38 am

            I love the 365. I didn’t want to love it, I wanted to be able to say that once again the hype fairies were working overtime. I carried a M9 in service, big, heavy, accurate. I own a G22 Gen4 and G23 Gen4 (EDC) that took some massaging to get right, I’ve been on the lookout for a 9mm to use as a BUG. My local range has had a 365 for rent for upwards of 6 months now. My buddy bought the first box of ammo so I wouldn’t have an excuse not to try it. Now I can’t put the stupid thing down. I practice with it every time I go in there. I personally have put over 1k rounds through the little thing and it just keeps getting better. At this point, I’m about ready to sell my G22 to finance the 365. Now, I didn’t pick it up with the gleeful expectation that it would feel and function like a Sig. In fact I was dreading it. I do not like most other Sig handguns, Especially the 320 and the 226. Maybe it’s because I shot the M9 for so long but the recoil action of the 320 feels foreign to me and the grip of the 226 feels wrong. I’m not saying they aren’t good guns, the 226 has proven itself time and time again, I’m just saying they don’t feel right. I was pleasantly surprised when I fired that first round and it poked exactly where I pointed. Not only that, it felt good. A micro felt good! Now, I confidently hit a 6-inch SnC at 45 feet with all 100rds. I run 1.5″ controlled pairs at 15 feet from a table draw in 1 sec including putting it back down. The little sucker can shoot, it can run, and I would challenge anyone to give it a spin and not smile in pleasant surprise at least once.

  • Joe June 1, 2018, 6:51 am

    I was going to go with the 365 but chose the HKP30sk instead.The difference in size is slight and it takes a 15 round magazine.

  • Curtai June 1, 2018, 6:27 am

    I still think it’s a little small… I went from a 938 to an M11. One of the owners at my local shop have one, am gonna see if I can try his first before I make a decision…

  • Leon W Jester June 1, 2018, 6:06 am

    Interesting, a smaller pistol with almost as many rounds as a Browning Hi-Power. Surprisingly accurate, although I once did something similar with a sandbagged Smith M-66 snubbie — which I still say shoots better than I do. One suggestion — put a wind sock on your microphone, at one point, your voice was lost in wind noise.

  • Nikki Magnusson June 1, 2018, 4:20 am

    Is that the Cowhide or Horsehide on your holster?

  • Don June 1, 2018, 3:15 am

    Like Bruce I’ve heard and seen this P365 fail on You Tube videos with trigger assembly issues along with firing pins breaking. No way this sub compact will be considered til Sig gets this straightened out. I wont carry a gun I have no confidence in!

    • Chris A June 5, 2018, 8:55 am

      They already did fix the problems. They stopped production and everything. Thats why they are so scarce 4 month after release announcement.

  • Kevin Niven June 1, 2018, 3:14 am

    Same here. I would be worried carrying it, I’m waiting for V2

  • Tom June 1, 2018, 2:48 am

    No failures or breakages of any kind, Clay? How many rounds have you put through this beast?

  • Bruce B May 31, 2018, 12:07 pm

    When I first heard about this lol Sig I was very excited. HOWEVER, lots of reports of firing pin tip breaking off and broken triggers. Plenty of examples with a bit of google-fu. Would NOT carry as primary SDG until those issues are addressed. Patiently waiting for P365v2.0

    • Chris A June 5, 2018, 8:57 am

      They already fixed those problems and are basically v2. Look into it.

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