Glock SBR Enclosure Comparison Final Thoughts

| August 1, 2014 | 17 Comments

This is the final post in my series comparing three different Glock enclosures: the FAB Defense KPOS, the CAA RONI, and the Hera Arms Triarii.

I am going to briefly summarize my experience with each enclosure, but I am not going to do a full recap on the features of each. If you want more detail, please see my individual posts on each enclosure.

This summary was delayed by problems with my personally-purchased RONI. It had 8 jams during testing, sparking speculation that I had an Airsoft version. My RONI was a “real steel” version, but I never received a reason for why I had 8 failures out of approximately 250 rounds fired.

The folks at Command Arms sent me another RONI for evaluation, but THAT unit was modified by a different tester somewhere in the past. The T&E unit suffered a stock malfunction, resulting in the top rail slamming into my cheek and cutting my face open.


I sent the second RONI back and got a third, and I was able to do some additional testing before compiling this summary.

Why I bought these

My wife is 5′ 2″ and has a limited reach. Her upper body strength is more than adequate to run a full-sized AK47 for short periods of time, but at the end of an 8 hour class fatigue was a major factor and her shooting and procedures suffered.

The goal was to get a lightweight, small, ultimately concealable platform for my wife. As a big bonus, we are “Glock folk,” and I imagined value in magazine commonality with our carry pistols as well as system familiarity compared to a pistol caliber carbine such as the Beretta Storm.

I sent off my paperwork to register a Gen 4 Glock 19 as an SBR with the ATF. When the stamp came back I was excited to try the KPOS as it was super small.

My excitement quickly faded as I encountered problems with the KPOS, sent the first one back due to a manufacturing defect, and still experienced reliability problems with the replacement.

No one else has written, to my knowledge, a comparison of the three most popular Glock enclosures. I bought these enclosures at my own expense so that someone in the future wouldn’t have to play the guessing game with their time and money.


Each enclosure was tested with at least 250 rounds of different ammunition and different magazines. The KPOS received the most testing, since I’ve owned it the longest, and the RONI received additional testing, combined, due to testing three different units.

As with children, the least troublesome unit got the least attention. The Hera Triarii only suffered two malfunctions during testing, and so we did not do any more shooting with it.

Why do you want one?

Before I proceed, you need to have a clear idea of why you are buying one of these enclosures. Is it for someone with specific physical requirements? Do you want something portable? Is magazine commonality important to you?

Your own personal requirements will strongly dictate which Glock enclosure is right for you, or if you should even own one at all.

For example, if portability and size are the most important factors for you, then the KPOS is your best choice, and the Hera Triarii should be excluded from your list. However if you want customization, then the Triarii is your #1 choice.


In my video summary, I broke down the attributes of these enclosures and ranked them. Here’s my assessment:

Size / portability

The KPOS wins this one. It’s the smallest, the most light weight, and folds up into the most compact package. The RONI is still small enough to put in a discreet carry bag with the stock collapsed. The Triarii is quite long — longer than my AR15 300 Blackout pistol when folded.



#3 Triarii

Adaptability / customization

The Triarii has the most customization options due to it’s size and the use of an AR15 buffer tube. You could put any AR15 stock on the Triarii, and of course use the detents in the buffer tube to adjust length of pull. The Triarii had the longest top rail of the enclosures I tested, as well as rails on each side and on the bottom. Conversely, the KPOS does not allow for any adjustment in the stock, and if you don’t like it you’re stuck.

#1 Triarii




None of the enclosures I tested were 100% reliable. I also evaluated my Gen 4 Glock 19 outside of the enclosures and fired 250 rounds through it. It worked without a single malfunction. I used different ammunition and different magazines, and three different people participated in the testing and all encountered failures of some kind.

I talked with the designer of the KPOS at SHOT Show 2014 and he said that the Gen 4 Glock was overall less reliable and more problematic than the 3rd generation versions. I don’t find this to be my experience, but I’m writing this as an additional data point. I also believe that the longer Glock 17 would be helpful, especially when using the KPOS because the 19’s ejection port is partially obscured by the enclosure.

I had a cascade of problems with the RONI. I had a series of problems with my first unit, and sent it directly to Command Arms, the US importer for the RONI, after the company I bought it from refused to help. Almost two months later, I haven’t heard back and have no idea what, if anything, is wrong with my unit.

The PR department from Command Arms sent me a black RONI unit for testing. It had zero malfunctions in approximately 80 rounds fired. I was going to do a longer test session but the stock locking mechanism had been tampered with by another tester and the stock failed. I am surprised Command Arms didn’t inspect their T&E units after receiving them, but I blame the previous user(s) of this RONI for the problem. I sent that one back and got a third RONI, but it suffered a malfunction in the first 33 round Glock factory magazine. I’d had enough.

#1 Triarii

#2 KPOS (although it had the worst failure of the bunch)



One of the minor reasons for going with a Glock enclosure is that I thought it would be cheaper than going with another platform. After all, I already owned the Glock, and aside from the stamp I wouldn’t need anything else besides the enclosure. It turns out that there are many other options for about the same price as an SBRed Glock in an enclosure.



#3 Triarii

One thing about the Triarii is that it’s death by a thousand cuts. The enclosure is $475 on its own, plus the side folding unit at $115, then a buffer tube, and stock. I went bare bones with a generic buffer tube and a MagPul MOE stock, but depending on what you choose you may drastically increase the cost of your build.


Would I buy a Glock enclosure all over again? No.

The most reliable enclosure was the longest and heaviest. If portability wasn’t a concern, I could have also considered the Beretta Storm. I could have tried an AR15 chambered in 9mm with the Law Tactical folding stock adapter, or perhaps a different SMG platform altogether, such as the Masterpiece Arms MAC-10.

I am still tinkering with my KPOS to make it work more reliably. I really like its size, but out of the box I wouldn’t recommend it without some serious caveats. Regardless of which enclosure you choose, you’re going to need to run some rounds with it, even if you’re sure your host Glock is 100% reliable.

If you’re still interested in getting a Glock SBR enclosure, I encourage you to use a Generation 3 Glock 17 as your starting platform. Some of my readers have responded that their enclosures are problem-free, and most of them have either Gen 3 Glocks or G17s or both. Best to maximize your odds.

Lastly, the customer support for these enclosures are all sub-standard. The company I bought my RONI from wasn’t helpful when I had problems with my enclosure, and dealing with CAA / Command Arms has been a slow and lengthy process. The Mako Group, the US importers of the KPOS, has a terrible track record of customer service and it’s been almost seven months since they promised me a replacement part at SHOT Show. Lan World Inc is the sole importer for the Triarii, so you’re not going to have the opportunity to shop on price. This won’t apply to you, but Lan World made me pay a deposit on my Triarii for testing, and then refused to take it back after I fired it. I told them what I intended to do, so they knew I would be shooting the Triarii. I’m out $700.

If you venture into the world of Glock SBRs, please send me a note with how it’s going. I’d like to get more data on why certain pistols may work better with certain enclosures, and hopefully get people paired up with the right solution before they spend their hard-earned money.

About the Author:

Short Barrel Shepherd Short Barrel Shepherd is a regular guy and works to make Web sites and mobile apps easier for people to use. He spends his free time attending fight-focused firearm, knife, and combatives training, motorcycling, writing, and playing games. His daily carry is a Glock 19 pistol and an AR15 .300 Blackout pistol in a backpack.

17 Comments on "Glock SBR Enclosure Comparison Final Thoughts"

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  1. Marc says:

    God Love ya SBS I give you credit to see this thing thru and help people to not make the poor choice of buying a good weapon and loading it with a bunch of crap that makes it less reliable.

  2. David says:

    Nice write-up. No surprises

    Just did another run of my Glock 17 Gen3 with my KPOS G2 yesterday evening, probably 100+ rounds. Only had one malf, which was a failure to eject. It was not obvious to me that the enclosure was to blame (I was using reloads, so it might have short-stroked). Zeroed in nicely at 25yds with my Holosun HS403C and Troy Micros, with the caveat that bulk 9mm is not exactly conducive to precision.

    Also, you CAN get a KPOS G2 with an M4 stock. I don’t think Mako sells them in the USA (yet), but Israeli Weapons sells setups with them. I am skeptical that this would be much of an upgrade – it seems like it would add rather a lot of weight and bulk, which is really the opposite of what I’m looking for in a PDW. The factory stock is angle adjustable, albeit it works best when straight-lined.

    Alternatives? One of these days, I’m going to dig up the cash and buy an SU-16D9 SBR (or build one from a PLR-16). 20″ folded, < 4lbs unloaded, 5.56×45, and takes AR mags. Besides a TP-9 / SPP SBR, that's the only gun I can think of that meets the ultra-small envelope that I'm looking for.

    USMG sells a neat minimalist folding stock setup for the MPA930SST, too… just not a huge fan of the platform, which is on the heavy side.

    • David says:

      I take it back; Mako sells the kits with the M4 stocks, but I don’t see an option to just buy the M4 stock upgrade. Might need to brave CS to ask for one.

  3. B says:

    Good Day Shep!

    Great analysis and thanks for spending the money, doing the work, and saving me the time and money of doing this myself LOL! I’ll start looking at scout rifles for the little lady then…been ogling the Kel-Tec SU16D or possibly E versions for her…at a mere 5 pounds loaded it’s got to do better than these block units. You’re a great spirit and I always enjoy reading your write ups! Peace to you brother!


  4. Jerrell says:

    I have a Roni and a Form 1’d Gen 3 Glock 17. It has run flawlessly in 9mm, and only had failures when running a .22 conversion kit. I haven’t had any failures personally, but others have experienced failures with the .22 kit.

    Again, I haven’t had any failures in 9mm. This is when running it suppressed and unsuppressed.

    • Short Barrel Shepherd Short Barrel Shepherd says:

      Hey there! I am glad you are having a great time with your Gen 3 G17. No one wants to come out and say it (except the designer of the KPOS), but I wonder if the Gen 4 G19 has some sort of design difference that makes it less reliable in enclosures.

  5. Dave Brown says:

    I was very interested in doing on of these in 40. I have MPAs set up in 9 and 45, and I am working on a AK C39 pistol. But I have a bunch of 40 to burn up. Your reviews discouraged me, however I don’t own a single Glock so something else may work. But, then I remembered seeing one of these creations made or at least sold by Sig. I checked it out, did some research and just picked up a NIB with a case, sling, and a red Sig laser on GunBroker for $190.00 at my door (they wanted $20 more but we dealt on it). I own some Sigs but nothing with a rail, but I have some 40s with a rail and will be seeing if this Sig ACP which stands for Adaptive Carbine Platform works out. A bunch of info says it will work fine with a Glock. Hope you see this as I don’t do all the social media stuff. Might some day but after having a cell for around 28 years the newest and greatest can wait. Great Review, Thanks Dave

    • Short Barrel Shepherd Short Barrel Shepherd says:

      Thanks for the comment! We’ve been trying to get the ACP law enforcement model for about two years. Some places wouldn’t sell it to us, and SIG has been unreliable about sending us a unit for testing. At this point I recommend that people buy a MasterPiece Arms DMG if they are considering a Glock enclosure, but in cases like yours the ACP may be a great choice.

      Keep us posted!

      • Dave Brown says:

        Well the SIG ACP ain’t an MPA. My MPAs are just Smoking! The SIG ACP seems to have a problem by taking away Ejection. Ejection gets real Wimpy. It appears to need a very firm wrist or shoulder mount if you are legal with that. I almost have mine working, but I am not sure it will be 99% reliable, 99 is my best rating as stuff happens. I am not using a SIG or Glock, but the pistol I am using runs just fine out of the ACP. I watched a guy use it on a Glock with good results. It appears SIG ain’t making them anymore?? Look around and you can pick one up for under $200.00. Thanks for the great info. Dave

  6. Dave Brown says:

    I Got the Darn SIG ACP to work! Sorry Sig, but I nicknamed it Sissy Sig, and thanks for being no help at all. SIG has discontinued this item, and they don’t even have any parts available, Go Figure. I wanted an extra set of rear adapters, but nope they don’t have any. Now I own a few Sig’s and expected more from them.

    Anyway I am using a Taurus PT840 as I want this in 40S&W as I have the other cals covered. Now I have Sig’s Star’s, Astra’s and others in 40 but none with rails so I picked the PT840. I was blaming the PT for not working in the Sig yet it ran fine out of it. I tried a PT809 worked just fine. I tried a 24/7 Gen2 in 45 and it had some ejection issues. Now I had been checking the 40 brass and found a few dented, and I noticed the same slight dent on the 45 brass.

    The finish on the Sig ACP is tuff stuff and I never found a mark on it so I was blaming the PT840. Did a little file work on the Sig and used red marker to cover it. Did a test and found 3 areas that were being hit by the PT840 Brass! During all of this I even tried the 809 recoil spring in the 840 and it still had problems. The reason was the difference in casing size and the 45 showed it best. So back to the PT840 in the Sig ACP, it works just fine, easy to rack once you get use to it, and break it in. I did take a little off the efector on the PT840 which allows the long case to stay in a little longer and also pops it out a little more to the front and right as that helps clear the sig ejection port.

    I added a folder and Blade Brace, and now I have my 40 cal creation. You can still find the Sig new on the net for cheap or at Sig for a $150 more. Yep, they are still selling them out, but do not plan to have any parts, Shame On Sig!

    The only thing I don’t like other then they send no instructions along, or should I say few, and that leads me to believe they didn’t real care, and just wanted the money, but I digress. The thing I don’t like is with the PT which has a 4 inch barrel there is about 5/8″ between the muzzle and the racker on the Sig Now that is normal, however, the blast makes a mess inside the Sig and the front of your pistol. I was shooting 2 types of reloads and one was really messy. So,I simply made a like shim that fits into the slide slot in front of the racker. It now sits about 1/16″ in front of the muzzle. Bingo it works and keeps the pistol much cleaner which is a good thing. I might pick up another Sig ACP on the cheap just to have it, and you can fab a rear adapter bracket if you break one. Thanks for all your efforts and Good Luck, Dave

    • Bleach says:

      Dave, would you be willing to post a picture of your final build? Also, any idea how the ACP functions while suppressed? Thanks in advance

  7. David says:

    Great review!!! I ordered one a Roni G2 for my registered Glock 32 I converted to a .40 via a threaded lone wolf barrel, so its essentially at G23. I also run an Octane 45 HD suppressor. My glock suppressed is NO FUN AT ALL due to the fact that I get a lot of blowback in my face. I am hoping that my suppressed glock will run reliably in RONI G2. Do you know anyone running a RONI G2 with a glock .40 and is it running any better than with the 9mm 17/19 glocks?

  8. Andres says:


    Bought RONI for CZ P-09 recently. 25 malfunctions from 50 rounds. Not good. Gun by itself- bang, gun in RONI- no bang.
    As it showed on later examination- the cocking lever either is bit too long or wrongly shaped. Handle will hit the frame of RONI, before the round gets fully chambered. Thus giving light trikes over and over again. It is clearly visible on primer- on no bang primers FP mark is oddly oval shaped.
    Reshaped the handle a bit- removed some material from lever ,,ears”, also portion of lever was sitting on rear sight, not allowing it to sit all the way down. Fixed this too. Had no chance to test it again. But after modifications it will probably work. Very simple fix, really, but I am not on CAA-s payroll, right, to do something what they should have done in first place.
    And all this happiness only for 400 euros:) Wrote to CAA to address this stupid problem. Think, they answered? Yeah, right…


  9. Cooter says:

    Glock 17 G4 and Roni enclosure. Using 9mm Tula ammo

    Typically works very good, really improves effective range.

    Had a few failures in 1000 rounds due to the spent casing not ejecting hard enough and causing a jam. I’m not sure the reason, but I have to speculate it’s the charging handle adding too much mass or rubbing on the enclosure. What actually happens is the round kicks out and it catches the top right of the plastic on the Roni behind the ejection port. They were easy to clear, however I would not opt for the spent brass catcher.

    Have issues with blowback of gasses around muzzle dirtying up the enclosure (ribbed so impossible to clean) Also covers the front 1/2″ of gun including making the night sight dirty until cleaned, possibly shortening the life.

    I came to same conclusion as author, that it’s not worth it for $300 plus $200 SBR stamp. I’m keeping it as a toy, but you’d be better served buying a carbine.

  10. Tactical Studmuffin says:

    I’ve had a stamped G17 Gen 4 in a Triarii with Magpul UBR for about 3 years now and haven’t had a single malfunction. I’m running an Eotech 512 on top. With the optic and added stability of the Triarii, she’s been a real tack driver out to about 75 yards. Even though it shoots great and never had a problem, I regret dumping all that money into it. I’m with the other guy regarding the Kel-Tec, so I now have a stamped PLR-16 with SU-16 underfolding stock. She ain’t the prettiest thing I’ve ever seen, but at less than 20″ inches folded and 30rds of 5.56, it beats the hell out of the G17/Triarii setup!
    I’ll keep the Triarii because I’ll never be able to recoup my investment on it, but it will never be anything more than a range toy.

    • Short Barrel Shepherd Short Barrel Shepherd says:

      Thanks for the comment — the more that people post about their experiences with these enclosures, the more I wish I had done it with a G17 or G22, ideally a Gen 3.

      We thought about keeping the enclosure around in my wife’s truck as a “convertible” platform in case of an extended incident, but in the end it didn’t make a lot of sense.

      Out of the three enclosures I had, the Triarii sold the most quickly. I think it’s far better made than the other two.

      Glad you like your PLR-16, if I had more $$$ I’d love to SBR one and try it out.

  11. xylen says:

    Hi, nice reviews I really like the way you are doing this!

    May I ask you also to test the IMI Kidon of IMI Defense – I didn’t find there
    one single video on youtube about someone testing it.

    Also the Micro roni which is comming out soon is for sure interesting.

    I would really love to see you testing those enclosures.

    Regards :

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