Upgrading the Kel-Tec KS7 Bullpup Shotgun

Adding a few aftermarket accessories enhanced the KS7′s versatility and cut recoil significantly.

By David Maccar | Published Dec 18, 2019 7:27 PM

Gun Reviews

When the KS7 shotgun first arrived from Kel-Tec, I gave you my first impressions after unboxing and running some dry fire drills for a couple days with it

A couple range trips followed during which I ran pretty much every kind of shell I had in my ammo drawer, from light target loads to heavy 00 Buck self defense loads, from 1.75” shells to 3” magnums.

The gun ran wonderfully. Even though the folks at Kel-Tec said they could vouch for its reliability feeding 1.75” shells like they do with the KSG, I had no real problems with them, but more on that later.

In short, I really dig this little gun. I kind of feel like it’s the perfect shotgun for a whole host of applications, chief of which being self and home defense. I say “kind of” because it hasn’t proven itself over a long enough time period yet, and because I haven’t gotten it really cruddy or dirty yet.

But, as it stands, if it had a choke tube adapter, I would absolutely turkey hunt with it and the groups I got with 1/4 oz. slugs prove it’s more than capable of taking a deer inside 50 yards.

It really is everything I loved about the KSG, but slimmer, lighter, and more nimble. The simplified design, which cuts the overall capacity from 14+1 in the KSG to 6+1 in the KS7, makes the gun easier and more instinctive to operate. I just really dig it.

But, that doesn’t mean I didn’t want to do a few things to it. Let’s be real here.

Trading the Carry Handle for a Top Rail

A stock Kel-Tec KS7 shotgun — A stock KS7 shotgun with its prominent carry handle, which also houses the gun’s integral iron sights. *Kel-Tec*

I did have some issues with the gun itself after spending some time at the range with it. The large and distinctive carry handle/integral iron sights assembly was just…cumbersome. It’s extremely light polymer, so it didn’t really add weight to the gun, just a lot of unnecessary height. It might make the KS7 look like a gun from Aliens, but it had to go.

The best and simplest alternative I found searching through the relatively small number aftermarket parts for the KS7 was the “Extended Precision Picatinny Top Rail” from Hi-Tech Custom Concepts

The Extended Precision Picatinny Top Rail from Hi-Tech Custom Concepts. Amazon

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Interestingly enough, the holes on the top rail from the KSG line up with the mounts on the KS7 and folks online have said you can swap it from one to the other, but the screws affixing the rail to my KSG must be secured with Red Loctite, because they weren’t budging.

Regardless, the KSG rail is 12.25” inches long, while the Hi-Tech rail is 15 inches, and since I planned to use iron sights on the KS7, a longer sight radius was also attractive to me.

The carry handle came off the KS7 easily and the same two bolts and washers are used to affix the new rail from Hi-Tech. Simple.

Replacing the stock carry handle with a Picatinny top rail drastically shrank the gun’s profile. *Jeff Rife*

It dramatically shrank the gun’s profile and made it feel more nimble and compact, though it added an ounce or two.

But the most important thing is now, I can use whatever irons I want or put on a red dot or any kind of optic. It’s a bit of versatility that, in my mind, the KS7 should have as an option.

Is the carry handle useful? Yes, it actually is. The KS7 is a tiny gun, and maneuvering it around without holding the grip and while being mindful of your muzzle is made a bit easier with the handle, simply because there aren’t too many places to grab the gun—and the iron’s are perfectly fine, I actually like the bright green front sight quite a bit. Plus, it offered locations to attach M-Lok rail sections or accessories, which I tried, and it did work, but having a light or laser unit up there felt awkward.

But for what it is and what it offers while limiting the optics I could use on the shotgun just didn’t add up for me.

For further testing, I installed a beefy set of irons with an adjustable rear peep sight I found in my parts cabinet—the origin of which I cannot recall, but they were just right and I’m sure any folding or fixed irons would be more than adequate. I kind of want to experiment and see how well it points with just a front sight, acting kind of like a bead sight.

Recoil Mitigation

Hi-Tech Custom Concepts Steel Defender muzzle brake — The Steel Defender muzzle brake from Hi-Tech Custom Concepts. *Hi-Tech Custom Concepts*

The next thing that had to be addressed was the recoil of the small, light shotgun. With target loads, the stock gun was as easy shooting as any pump gun. Things didn’t start getting uncomfortable until I started shooting 6 rounds of 2.75” self defense loads. The 3” magnums were also kind of punishing, but they always are.

A lot has been said on the Interwebs about how awful the recoil of this shotgun is, so I was prepared for the worst—but all in all, I found the KS7 to be easily manageable and not worthy of the criticism it has received in that area. Still, it could’ve been a bit more comfortable to shoot with the heavier stuff.

Hi-Tech also makes two different muzzle brakes for the KS7. The Howitzer 70 looks, as the name would suggest, like a wide brake on an artillery piece. I went with the more streamlined Steel Defender brake which is tubular and surrounded with ports.

It’s CNC machined from 416 stainless and just over 2 inches long with a weight of 4 oz. Hi-Tech includes a special too that attached to a 1/4″ socket wrench so you can remove the factory barrel nut.

Hi-Tech Custom Concepts muzzle brake on a keltec ks7 shotgun — The installed Steel Defender muzzle brake from Hi-Tech Custom Concepts. *Jeff Rife*

The magazine cap has to be removed so you can get the tool on the barrel nut, so that’s the first step. It simply unscrews, but its under tension from the magazine tube spring, which will go flying out unless you unscrew it slowly. You might have to wrap it in a cloth and use some pliers to get it started.

The barrel nut is not Loctited on, but it is torqued down pretty good. The best way to remove it is to secure the gun in a gun vise or pad a regular vise and lock it down. Make sure to clamp the receiver and not another part of the shotgun, as you could cause the polymer parts to flex and weaken or snap.

The best and safest way to do this is by using the KS7 Vise Block from M-Carbo, which is what I ended up doing to make sure you don’t end up damaging the shotgun.

Once it’s off, you just screw the muzzle brake on, BUT, you’ll have to put the mag tube back together FIRST.

The base of the brake fits very closely to the mag tube cap and the fatter part actually overlaps it. So in the future, to remove the mag tube cap, spring, and follower, the brake must also be removed.

And partially for this reason DO NOT LOCTITE THE BRAKE ONTO THE BARREL. There is no need for this. If you wrap an appropriately sized Allen wrench in tape and slip it through the holes in the brake, you’ll have more than enough torque to screw it down tightly by hand and that’s how it should be done.

After a long range session, just make sure it hasn’t loosened up under recoil, but mine hasn’t after a good 300 rounds, some of which kicked pretty hard.

Kel-Tec Hi Vis Magazine — You can see the orange hi-vis magazine follower here, which makes it a bit easier to confirm the tube is empty at a glance. *Jeff Rife*

While I was doing this step and had the mag tube spring out, I figured I would upgrade the follower with a high-vis orange one from M-Carbo, but I think pretty much any 12-gauge follower will work.

That hopefully took care of some felt recoil at the front of the gun, now for the other end.

I’ve had a Limbsaver Airtech slip-on recoil pad on my KSG pretty much since I got it, so I figured the same solution would work well for the KS7, and it does. The shape and contours fit the gun aesthetically and nothing sticks out to get caught on your gear or folds in your clothing. It also adds a little bit to the length of pull, which makes the gun fit me a little better overall and smoother to shoulder, but if you have a smaller frame, it’s something to think about.

limbsaver recoil pad — The medium-sized Limbsaver Airtech Slip-on Recoil Pad fits the KS7 great and makes it a lot more comfortable to shoot. *Limbsaver*

The medium sized slip-on model fits very well and does not come off easily during regular use, but if you want it to be more secure for jumping out of a plane or whatever it is you do, you could use some 100mph tape to secure it, or some double sided tape for a cleaner look. Plus, the lines of the pad match up pretty great with the KS7’s buttstock.

Extra Accessories

I couldn’t quite stop decking out the KS7 there. I added a 7-shell Velcro card carrier to the right side of the stock, which is nice because it’s easily removable if you don’t need it, leaving just a fuzzy Velcro patch.

I also wanted to add a gun light of some kind to the shotgun so it would be ready for a home defense set-up, but I had some trouble with this step once I decided on the Crimson Trace Railmaster Pro combo light and laser.

Crimson Trace Railmaster Pro Mini Angle Rail — Here you can see the Crimson Trace Railmaster Pro combo green laser and light mounted to the side of the KS7 with the Mini Angle Rail from Hi-Tech Custom. *Jeff Rife*

With the carry handle gone, there are only two M-LOK slots remaining on the gun and they are on either side of the slide handle, but neither of them are stable enough for a laser sight to hold zero. So I grabbed the Mini Angle Rail that Hi-Tech Custom designed for the KSG, which mounts on the top rail and provides a side rail platform.

Because of the different shape of the slide and action bars, the rail can’t be mounted on the KS7 in a position forward of the trigger like it can on the KSG. However, it can be mounted almost directly above the trigger and pistol grip, which is where it went. I’m able to easily activate the laser sight/light with the thumb of my shooting hand without moving from the shooting position and it doesn’t get in the way of anything. Though the windage and elevation adjustments on the laser were reversed because the sight is mounted on the side, I was able to zero it pretty easily.

M-Carbo plugs on Keltec KS7 shotgun. — This accessory from M-Carbo plugs the hollow grip of the KS7 but also provides a storage space for an extra 12 gauge shell. *Jeff Rife*

There was one more little thing that had to be added.

As I was perusing the offerings for the KS7 from M-Carbo, I saw they make an insert that fills the hollow polymer grip on the KS7…something I wanted to do the moment I got the gun, but it also houses a single 12 gauge shell as a last ditch backup.

While the finish on the polymer insert is a little rough, it is designed well and it stayed secure with a shell in it through lots of shooting and recoil, but was still easy to remove with your fingers (without almost ripping off a nail). It’s a little gimmicky, but I like it simply because it fills up that hollow pistol grip, and you don’t have to put a spare shell in there. You can use it to store batteries, a small flashlight, or whatever you want.

Performance

man firing upgraded ks7 shotgun — The upgraded KS7 was just plain fun to shoot. *Jeff Rife*

The KS7 is a fine shotgun out of the box, let’s get that straight. It handles well, functions reliably, and has a number of solid features in addition to the advantages of being a lightweight, nimble bullpup.

And the bulky carry handle is useful and the sights it houses are perfectly fine. The only time the stock shotgun was a little unwieldy or uncomfortable to shoot, in my opinion, was after a two-hour range session and when firing a full mag of hard kicking defensive shells or magnums.

I just wanted a little more adaptability as far as optics and sights, and a spot to add a light/laser, as I feel it’s an important feature on a defensive firearm—and I like shooting the thing, so I wanted it to be a little more Cadillac and a little less Econoline in terms of comfort for longer days at the range with boxes of target loads. Plus, the more comfortable you can be while practicing at the range, the more you’ll practice and the less likely you’ll develop something nasty like a flinch.

That said, the main goals of these upgrades were to make the gun more compact and to reduce felt recoil and muzzle rise—and those goals were ultimately achieved.

After all the upgrades were made, I immediately liked the new rail and iron sights set-up when I got to the range. The lower irons on the rail let me get down on the shotgun without that handle getting in my view. It felt a lot more natural.

As far as recoil, the difference was pretty remarkable. Hi-Tech Custom says the Steel Defender brake reduces felt recoil by up to 30 percent, and I’d have to say, that sounds about right. Combined with the Limbsaver pad, the little shotgun became an absolute joy to shoot, no matter what I fed it.

I also wanted to conduct an experiment with 1.75” shells. I got a good supply of Federal’s new Shorty shotshells in No. 4 Buck, No. 8 Birdshot, and 1/4 oz. slugs.

The gun kicked very little with the small shells, and they cycled well through several boxes of ammo…and it’s not hard to go through a box. You can fit 11 of the Shorty shells in the mag tube of the KS7.

If you short stroke the action at all, it won’t pick up a fresh shell—which is the case with 2.75” shells as well (and is the case with the KSG), though it’s less forgiving with the smaller hulls.

Everything seemed to function really well and I even shot a fist-sized group at 30 yards with the slug loads off hand.

But there was one weird occurrence. I loaded a whole box of shells—10 rounds—in to the tube, but I only fired nine shots. The gun was empty. At the range I thought I mis-counted or had already grabbed a round out of that box earlier.

Only when examining some video (above) my buddy shot of our range session did we see what happened. For some reason, the KS7 seemed to eject an unfired shell along with the empty hull of a fired shell at the same time. After seeing the footage, I did recall picking up an unfired shell from the deck when we were policing our hulls. That’s not great, but it didn’t jam and the trigger didn’t fall on an empty chamber.

It will require some more testing to see if I can replicate that particular problem.

Applications

Overall, with these upgrades, the KS7 is about the perfect home defense shotgun, and a pretty great all around shotgun.

I wouldn’t exactly trust it as a home defense gun loaded with 1.75” shells just yet, though that 11+1 capacity is very attractive.

Still, with 2.75” shells you have 6+1 in the gun and 7 more rounds on the carrier, so 14 loads of 12 gauge 00 Buck on board, or whatever you choose, is quite formidable in a very small package.

Plus, from a home defense perspective, it’s important to note that the compact bullpup design means you can actually aim the shotgun with one hand—and not some shaky sort of aiming and could maybe hit something the size of a car door aiming—but get an actual, steady sight picture. And firing it one-handed doesn’t feel much different than firing it two-handed. This can be said of almost all bullpup long guns. The mass of the receiver is so far back that it can easily be balanced and the weight easily held with one hand.

Why is this important? Well, during a home defense situation, though you should avoid doing so at all costs, you might end up moving down a hallway or from one room to another. Not only does the short length of the gun mean it’s harder for a bad actor to grab it, the fact that you can manipulate it well with one hand means you can use the other hand to do things like open doors or flip on light switches without lowering your gun or being defenseless for a moment or two.

Plus, if you can aim and shoot it with one hand, then you can confidently maneuver it in pretty much any way with one hand.

The shorter gun is also much easier to maneuver in the confines of a home or apartment while still providing the ballistic advantages of an 18.5″ barrel.

Think about this…a KS7 is just 26.1 inches long (without the aftermarket brake and recoil pad).

A 12-gauge Mossberg 590 has a capacity of 8+1 shells, but it has an overall length of 41 inches with a 20 inch barrel. That is a huge difference.

As the barrel on a traditional pump shotgun gets shorter, so does the mag tube, which reduces capacity.

For example, the Mossberg ATI Tactical has an 18.5” barrel, just like the KS7, but a capacity of 5+1 while the overall length is still 36.37 inches—more than 10 inches longer than the KS7 and holding one fewer shell in the magazine, with the same barrel length. That’s the advantage of the bullpup design.