SRU Precision SARB-15 Bullpup Kit: Space Guns Are On The Menu

Without question, the AR-15/AR-180 and their derivatives are the most flexible and modifiable family of firearms ever designed. Combine that with some injection molding technology and a flair for the dramatic, and you have unlocked some truly insane options.

This is exactly one such option. The SRU Precision SARB-15 Bullpup Kit takes an unsuspecting AR upper and turns it into something new, different, and a little strange.

But first, you’ll need the right upper. This kit is only compatible with uppers that use internal recoil springs or short-stroke BCGs like the Brownells BRN-180, PSA JAKL, or Foxtrot Mike FM-15. Mine is the PSA JAKL 13.7” barrel pin and welded to 16”.

BUT… WHY?

Don’t ask “why”, ask “why not”. End of the day, there was a JAKL upper sitting in my safe that wasn’t being actively used and this looked like a fun way of putting it back into the rotation.

Why you might want to bullpup your own JAKL or similar upper, who can say. Maybe you’re bored, maybe you want to give yourself a new challenge, maybe you just need something new to show off to your friends while your friends laugh.

The kit is really well made. It works. It’s pretty cool. But more on all of that later.

INSTALLATION

Instructions provided by SRU are actually pretty easy to follow. While PDF form only and no videos, as long as you’re able to assemble Lego kits or IKEA bookshelves, you’ll be fine. I had to backtrack once in the process but that was user error. Pro-tip, make sure your safety is on the correct side for your thumb.

Major note about the grip that you choose — the first grip lying around on my bench that was within reach was a Magpul MOE. This didn’t work out super well and made it hard for my thumb to actually flip the safety without breaking my grip.

This was switched out for a Die Free Kung Fu Grip and it made a huge difference. Because this is a fairly short length of pull for me, the more vertical angle of the Kung Fu Grip helped align the ergonomics better and not only feels better to hold but also gives me the reach I need for safety.

Your mileage may vary, but it’s something to keep in mind. If your first grip choice doesn’t feel right, try something with a different angle.

ON THE RANGE

I don’t like bullpups. They just don’t work for me and I normally avoid them. With that in mind, my expectations were kind of low for the SARB-15. To my shock and amazement… this is actually pretty decent.

Reliability for my JAKL has been near perfect and that continued once it was in the bullpup configuration. No malfs of any kind during testing.

Accuracy is the same as before the kit at about 1.5 MOA depending on ammo. The trigger actually feels almost the same except for it being a different trigger shoe. It’s amazing that the linkage used to bullpup a JAKL is actually better than the linkage most other bullpups have that were actually designed to be bullpups.

Feel and ergonomics of the gun feel like a bullpup. That’s a good thing and a bad thing depending on how you look at it, but it is what it is.

The most odd thing about the kit is how it handles the safety. While it gives you a new safety at your firing grip, it also retains the safety on your lower. The lower safety must be set to “fire” for the gun to work. If it is on “safe”, detaking the safety off on the front safety does nothing.

Because the SARB-15 is a conversion, you’re missing a couple of the small quality-of-life features that some other bullpups give you — like a bolt release behind/near the magazine or a magazine release near your grip area. 

However, the mag release you do have is a large lever-style release that is easy to use and just requires a different approach to your manual of arms. Standard AR-15 bolt release is in a new location due to being bullpuped, but works the same as always and doesn’t pose an issue.

Give it some dry fire and a couple drills on the range and everything clicks into place.

Frankly, it took me by surprise to find how quickly getting used to the new bullpup took. While none of my drill times improved because of the new configuration, none of them really dropped badly either — except reloads. Expected, but worth knowing.

The SARB-15 just feels good. 

One weakness of the AR-15 in general is height over bore (the distance between the center of your optic and the center of your bore). This really isn’t something you can avoid with standard AR-15 and AR-15-ish designs like the JAKL, but it gets worse with the bullpup configuration.

For context, my PRS bolt-action rifle has a 2.25” HOB, and the go-to AR-15 that I can use with NV is 3.3” HOB. The SARB-15/JAKL is a monstrous 4.3” HOB.

Why? Your cheek weld is the rear of the top rail of the JAKL upper. This really doesn’t allow you to get much lower unless you want to crush your face into the gun. 

This isn’t unique to the SARB-15, a higher HOB is pretty normal for bullpups in general. But it does feel a little strange and takes some getting use to when you’re shooting close targets.

My setup isn’t a “go-to-war” quality method of addressing the HOB, but it’s what could be done with the parts on my shelf. An Amazon special mount combined with a SIG Sauer Romeo MSR Gen II and an SIG Juliet 4 gives me enough height to shoot without putting a kink in my neck.

WORTH IT?

You’re not going to improve your JAKL or other AR-15 upper by bullpuping it. I would argue that in most quantifiable ways, the gun is less ergonomic, harder to use, and worse in most metrics. But I would say that about any bullpup. 

That said, the SARB-15 is still pretty cool. It’s fun, it’s interesting, it makes something old a bit newer, and it gives you an option that you didn’t have before. For the bullpup curious like me, it’s actually a solid option. My JAKL isn’t locked into being a bullpup forever, but the odd time that I do want to pull out a bullpup that option is available to me without having to spend 4 figures on a dedicated rifle that will spend more time in the safe than on the range.

And what should be most shocking is that for me at least, the SARB-15 is a better bullpup than most dedicated bullpups that have passed through my hands. Better trigger, better feel, better balance, and better flexibility. 

LOOSE ROUNDS

Once you account for price of the base rifle and the cost of the SARB-15, you’re into real bullpup money. But the benefit is that instead of having one rifle that does one thing, you basically have two rifles that do two things. 

The SARB-15 isn’t perfect, but with my biggest annoyance being the two safeties the downsides of the SARB-15 really aren’t major. For me, this will be a range toy and maybe a rifle to take to local matches when I’m feeling like being a little weird. This won’t be the new rifle for some elite SOF unit, but that doesn’t mean it can’t have a home in your collection.

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