M*CARBO Brotherhood

S2K v Ruger PC9

For those of you that have/shot both.

I own both and think they are both awesome guns. I got the PC9 first because it too uses Glock mags and it is near impossible to get an S2K in 9, especially G19 which is what I was holding out for. I am not asking any of us fan boys/girls which is better. They both have advantages in their own ways, and other than being portable PCCs, they both have their place for different needs.

One thing that will be interesting is when Magpul finally releases their new Backpacker stock for the PC9. That will bring the two much closer in terms of portability. The PC9 does have more limited space on the rail, but the rail on the PC9 is much more solid that the molded plastic rail of the S2K and the overall build quality is much better. Very different guns.

What surprises me is the recoil. I find that even though the STOCK PC9 is a heavier, more robust weapon, my full MCARBO rebuild S2Ks with all the recoil dampening gear have less retort that the PC9, even the 40. I’m thinking that is a testament to the fantastic products MCARBO has made for the S2K as opposed to some inherent quality of the guns.

I have bought all the MCARBO upgrades for The PC9 but have yet to install them. It will be interesting to see how they compare once installed. I’m waiting for Magpul to release the stock to do it all at the same time.



I was waiting for this comparison post on these two particular carbines. I’m sure it’s been done in the past, to lazy to find it. It’s all about systems for me, I do have fun guns don’t get me wrong.
For me, the S2K just fits into my system better. It’s portability, low recoil, accessory mounted options etc are to much for the PC9 make up IMO (I have both of these carbines). If you were to deck out a PC9 with all the Midwest Industries goodies you’ll still have that portability issue.
Recoil is much more controllable on the S2K due it’s blowback characteristics and larger bolt group than that of PC9, my follow up shots are wee faster on the S2K.
My opinion is coming from testing and trying integrate weapons into a system that my family can adapt to and are learning to do that. Yes, I have integrated the S2K into my home defense system, particularly the wife does not like the 12ga shotgun being petite its not feasible for her to grab that in home defense situation where the S2K would be. Just my 2¢


Overall, the PC9 is a much better quality firearm. On the other hand, the S2k is simple, and best of all fits under a truck seat. In these times, having a rifle too as opposed to only having a pistol is a necessity - witness Kyle Rittenhouse. That confrontation would probably have ended differently if he’d only had a handgun.

Barring a shotgun, a lightweight short carbine like the S2k is probably better for home defense because it’s easier to maneuver and clear around corners. A fun stick in either PCC is also a good thing - there may be more than one intruder, and each will likely need multiple hits to take them down. To me, the S2k is mostly a range toy but it has its place and is better than just a pistol.

Of the two, I think only the PC9 will be handed down to my descendents because the S2k will probably not last that long - plastic gets brittle, and moving parts like the hammer and sear pivot in plastic holes which will eventually wear out. Also, I expect Ruger to be around a lot longer than Keltec, and a lifetime warranty doesn’t necessarily mean your lifetime.

The Backpacker stock is better than nothing but it looks awkward - I’d think a skeletonized folding stock would be better - the total length would be almost identical to the Backpacker stock and deploys in a second. I rarely take my PC9 down because you must separate the pieces in a pack or they’ll bang against each other and make noise, not to mention get scratched, and it takes time to put it back together. That’s the true beauty of the S2k - it’s compact but ready in an instant. I’d rather have the better-made gun but size and weight are higher priority if you must bug out. Just make sure to carry spare parts.


Or… Replace ALL the S2K internals with MCARBO parts. :wink:


That is really the answer I was looking for. Answer in front of my eyes and the blind could not see. That big S2K bolt really makes sense not that you put it out there. When I took it down the first time I really did pause to check out that hunk-o-metal.

It never made much sense that they would be noticeably different since they are in essence the same barrel length but the PC9 has more overall weight to it.

Good on ya 00Buck


I’ve done that, but even with the MCARBO parts the S2K is lower quality - those replacement parts bring it up to minimum acceptable standards. The S2k depends on polymer for its light weight, but it also depends on polymer to not wear out, and that’s provably false or there’d be no need to replace the hammer bushing and feed ramp after only a few hundred rounds. The S2k WILL wear out much faster than a firearm that uses metal for load bearing and moving surfaces, even with all the MCARBO improvements. I also expect at some point the polymer will get brittle, making it unsafe to use at all.


Serviceability of a weapon also depends on care and use. I think your polymer concern is really a good point. I think there are preservatives that can be rubbed in that extends life?

I absolutely agree that the PC9 is overall a much better build and finish. What bothers me about almost all of these guns is the reliance on plastic internal parts. For example, the PC9 recoil spring retainer is plastic and I have read that this is wearing out/failing for many people at around 1000 rounds. That’s less than ten trips to the range for me. That is not what I call long term durability for any gun. What Ruger was thinking is beyond me. When I replace mine with the MCARBO part, I will post pics (that might be a while because I’m waiting for the Magpul stock to be released and do the build in one sitting).

Neither gun from the factory is a daily firefight weapon until the internals are upgraded. With the upgrades, if you are in a long term situation where you need to fight everyday (that ammo thingy comes into play), You’re going to be wishing for your AR.

My original post was more about handling and recoil. I am constantly amazed and impressed at the accuracy of the S2K. IMO, the S2K is a much more nimble gun, faster on target and as 00Buck solved for me, the lower recoil makes follow up shots faster. The PC9 is a more versatile platform. With decent optics, the ergonomics are more comfortable for longer ranges. Though I have a Bushnell TSR on the PC9, I am really thinking of getting a 4X scope and run both on QR mounts.

If I’m shooting steel or in a situation where I’m going to potentially be in regular fights, I would take my S2K. It is a more fun gun to shoot. As an outdoor gun where I might have to try and take game at a distance and fight an occasional skirmish, I think the PC9 and it’s versatility is the way to go.

FORTUNATELY, I have five bug out bags because there are five of us and we can take both!



I take good care of all my firearms. One big ‘plus’ of the PC9 is the internals can be taken apart and cleaned/lubed regularly. Taking apart the S2k is certainly not something you do very often. Yes, the PC9 trigger group is in plastic but the load-bearing/moving parts are supported by pins that don’t move so wear is a lot less. Your point about the recoil spring retainer is valid - I’ve had to reseat the plastic one more than once - but even if it fails, it doesn’t affect whether the gun will function. Other than that, the stock is the only other thing plastic, and the gun will still function if it fails.

The S2k is fun to shoot and accurate, but I’d hate to depend on it not breaking when I need it most. The bolt handle is a big weakness - mine has broken before. When you say, "“get the MCARBO one”, I have to disagree - getting that tiny retainer pin in, even the improved one, isn’t a trivial thing, and takes time - time you may not have in a danger situation, especially if you’re amped up.

You’re right about the AR, especially when you consider the difference in ammo weight compared to firepower. The flip side is the bulkiness of magazines - you can carry 9mm mags, even funsticks, in a pocket. A 4x scope is indeed an option, though more so for the PC9 since the rail on the S2k is, except for an RD, too far forward for a good sight picture and you lose much of the quickness getting on target.

Unfortunately for me, there’s only me to carry anything heavy, so I have to ‘weigh’ what’s important carefully.


So I haven’t shot the S2K, but have the ruger pc9. Which is one of my favorite guns I own. Glad to know magpul is coming out with the back pack. I am curious what optics y’all might have on pc9. I have the romeo5. Mcarbo upgrades on pc9 trigger and extended bolt release

I really enjoyed getting my S2K and upgrading it with all the Mcarbo parts. I liked the concept of a portable PCC utilizing the same caliber and mags as a handgun I had already carried for years. I had the Glock model in 40 cal. I just never had the confidence to bet my life on it. Too much plastic and too involved and difficult of a process to break it down for thorough cleaning and service. Considering the work I do now and the growing unrest in the country I wanted a gun that was very reliable, yet fit many of the characteristics possessed by the S2K. It was a fun gun, but I decided I needed to invest my resources into a serious work weapon. I sold my S2K and bought the CMMG Banshee 200 AR pistol w/8 in barrel. First it’s an AR platform, which I am already very familiar with. It also takes the same 40 cal Glock mags I previously had. It takes everything from my 10 rd mags to the 15’s and 22rd ones. The CMMG’s overall length, with the stock compressed, is only about 5 inches longer than my folded S2K. With the integral rail there was no problem adding Magpul flip up sights and a Burris fastfire 3 red dot. I don’t have any experience with the Ruger PC9, but have owned other Rugers and have always had respect for the quality of the arms they produced. It was the CMMG’s length, portability, AR type platform, overall quality and fit for my needs that made me choose it over the other two. The S2k was fine for awhile, until I could find and afford something that just fitsCMMG Banshee 200 the mission better.


What is the recoil like on the CMMG Banshee?


Recoil and muzzle rise are not a problem, very light for caliber.


I have considerably more than 1000 rounds through mine and the plastic retainer isn’t in tip-top shape but it’s still there and works okay. After looking at MCARBO’s stainless retainer, I decided $15 + $6 shipping for what’s essentially a washer was more than I wanted to spend so I contacted Ruger and asked how to get another stock retainer and they shipped two to me for free.


I use a Romeo5 with a Vortex 5x magnifier. Yeah, the Vortex didn’t cost $200 but it does the job and doesn’t blur the Romeo’s 1moa dot.



I have the CMMG Banshee 300 in 9mm with the 5" barrel, it has a Radial Delayed Blowback action that makes it a very soft shooter. The delayed blowback is quite interesting and everyone that has shot it has really liked it.


WTF, Y’all didn’t tell me about the PRICE of the CMMG 9mm… $1400 fudge that! :crazy_face::joy:


The CMMG looks intriguing. Like 00Buck, I was kind of sticker shocked when I saw the price, though they look top quality. Lead time on a purchase is 20+ weeks.

You’re also comparing a pistol to a carbine. The big draw for me on both the S2K and PC9 is the 16 inch barrel. The added length of the carbines increases the muzzle energy of these pistol calibers significantly. That is the reason why we choose this type of platform, no?

The CMMG platforms are cool and probably awesome little guns. IMO, they are just fancy PISTOLS, and I don’t see, for this discussion, how the CMMG is relevant.

I already have pistols in these calibers. The point is to have the improved ballistics that a portable carbine offers that matches the caliber/magazines of the sidearm to be carried/matched with it.


Sure, if had a money tree out back I’d spring for one of those CMMG doohickies. I agree @MOLON_LABE the price shocked me more than anything. Maybe when my rich Uncle Louie passes to the great beyond I’ll be the benefactor of his inheritance :joy: Maybe a CMMG Banshee is in my future :thinking::rofl:


Yeah. But a Money tree buys my 300 model in Bazooka green. How F’n Cool would that be? I’d feel like one of those plastic soldiers I used to play with as a kid! :gun::bomb::firecracker::us:

The burnt bronze and stormtrooper white look really sweet also.

Did I forget to mention that small detail? I have the CMMG Banshee in 40 cal and it was only $1350.00. I guess you have to really want one bad at these prices.