Mesa Tactical’s LEO Gen II Telescoping Stock Adapter is one of those upgrades that just makes sense. When paired with the KynSHOT hydraulic buffer from the LEO Recoil Starter Pack (SKU 90020), it noticeably reduces recoil and adds real versatility to the Mossberg 500 and 590 platforms. You get the comfort and adjustability of an AR-style collapsible stock without giving up the reliability of a pump gun. For anyone building a defensive or range-ready Mossberg, this setup feels like the right place to start.
What’s in the Box
- LEO Gen II Telescoping Stock Adapter
- KynSHOT hydraulic recoil buffer (LEO Recoil Starter Pack, SKU 90020)
- Mounting hardware
- Sling swivel, double-ended flush cup
Everything needed for installation is included. You don’t need to be a gunsmith, though a torque wrench is suggested.
Key Specs & Claims
- Compatibility: Designed for Mossberg 500 / 590 pump-action shotguns in both 12- and 20-gauge configurations.
- Construction: A356 aircraft-grade aluminum with a durable powder-coat finish that matches Mesa Tactical’s typical quality.
- Stock & Grip Options: Works with AR-style collapsible stocks and pistol grips, giving the Mossberg platform true modularity.
- Recoil Reduction: The selectable hydraulic KynSHOT buffer (included in the LEO Recoil Starter Pack, SKU 90020) claims up to 70–90% felt recoil reduction, depending on the damping setting.
- Price Range: $124.95 – $473.95, depending on configuration and whether the hydraulic buffer is included. (I opted for the $403.95 kit, as I already had a Hogue grip and stock)
First impressions
Out of the box, the construction and finish are what you’d expect from Mesa Tactical – solid, with attention to detail, and built to last. The LEO Gen II adapter installs with ease and fits well. The design feels intentional, not like a retrofit. Once the KynSHOT buffer and stock are mounted, the overall balance is surprisingly good, especially for a shotgun that’s often front-heavy. Everything about it feels purpose-driven, made for hard use rather than looks.
Installation
Mesa claims no gunsmithing is required, and that’s accurate. Here’s what it takes:
- Remove your existing stock
- Attach the LEO adapter to the receiver and add your favorite AR-style grip
- Install the KynSHOT buffer
- Tighten the locking nut, check alignment, and attach the sling if desired
- Slip your AR-style stock onto the adapter and adjust to the desired LOP
From start to finish, it took me about 30 minutes, including adding my Hogue grip and stock. My best advice is to read the full installation guide here before ordering so there are no surprises. Once it’s all together, make sure to test the fit with your sights and cheek weld. I was happy to find that my ghost ring sight system is perfectly aligned with this setup.
Fit, Ergonomics & Handling
Adjusting the length of pull is straightforward. At its shortest, it’s tight for compact carry or storage; at its longest, it gives plenty of room for a solid cheek weld. The pistol grip feels natural, and the stock balance is good, even for a loaded Mossberg 590. If you shoot with body armor or in tactical gear, the extra adjustability should make a noticeable difference in comfort.
Recoil & Performance
We tested this using a variety of 12-gauge shells. We ran everything from 2-3/4″ bird shot up to 3″ slugs and 00 buck shot. The KynSHOT buffer works exactly as advertised: the key is matching the setting to your ammo. On the lower setting, light rounds were almost laughable. Heavier rounds felt a little softer, but it took the edge off them.
Switching to the higher damping setting, those 3″ rounds were nicely tamed. You still feel them, but you won’t wake up sore the following morning. At that higher setting, the damping was too stiff for the lighter rounds, so the piston didn’t seem to compress as much. When set appropriately, muzzle rise is reduced, and follow-up shots are faster and easier to control.
Note that I don’t have a lab-calibrated shoulder, and tuning is key here. I can’t say that recoil was reduced by exactly 90% every time, but it’s a huge improvement, especially on heavier 12-gauge loads. My ammo budget will give out before my shoulder will. And no issues with feed, ejection, or reliability popped up during testing. Shooters varied from 120 pounds to 290 pounds, slight builds to stocky. None of us are professional operators, just firearms enthusiasts with varying degrees of skill. And we all had a good time shooting this setup.
KynSHOT Adjustments
As mentioned, adjustments can’t be done on the fly. The entire process is shown on the KynSHOT Hydraulic Buffer Manual page. Once it’s removed for access to the buffer, you use the included wrench to loosen a set screw. Then all you need is a flat-blade screwdriver to switch between O (open), MD (medium damped), and HD (heavy damped). The full travel of the piston is approximately 3/4″, which is enough to take the edge off even the heaviest of loads.
Durability & Build Quality
After a few hundred rounds, the Mesa Tactical LEO Gen II adapter hasn’t loosened up or shown any wear. Threads are tight, the powder-coat finish looks new, and the sling mount remains solid. It feels overbuilt in the best way – like it’ll handle thousands of rounds without needing much attention. When checking the gaps between the adapter, receiver, and grip, I noticed a few small touches. There’s a small relief on the left side for better access to the slide release. Mesa Tactical designed it with a wide groove on the right side to give your trigger finger a more natural angle as well.
Pros & Cons
Pros:
- Hydraulic damping works and is selectable
- AR-style stock support adds versatility
- Solid construction, powdercoat finish
- No gunsmithing required
- Integrated sling attachment points
Cons:
- Price varies a lot depending on kit and configuration
- Must remove stock and buffer to adjust damping.
- Some SKUs require buying parts separately
- Cheek weld and stock alignment can take minor tweaking
Comparison and Recommended Use
Compared to other Mossberg stock adapters, the Gen II stands out for its robust construction. No polymer here, it’s all metal, and built for duty. Combined with the KynSHOT, which lets you tune your recoil to your preference, there is no comparison. Price is on the higher side for adapters, but I have tried the less expensive ones, and the difference is night and day. Quality costs money.
If you’re a tactical shooter, LE officer, or competitive shooter who wants AR ergonomics on a Mossberg platform, this is a solid choice. Also great if you’re sensitive to recoil or need a collapsible stock for transport. In a world without $200 tax stamps, I would absolutely consider this for the Mossberg Shockwave. The Shockwave is a great defensive option, though its reduced weight contributes to more felt recoil. It gives up three rounds to my 590, but I suspect that if I need to reload, I’ve already lost.
Verdict
The Mesa Tactical LEO Gen II Telescoping Stock Adapter with the KynSHOT buffer is worth it if you want adjustability and comfort without doing permanent mods. It’s not cheap, but it’s solidly built, easy to install, and genuinely improves recoil management. If you want to add AR-style stock functionality to your Mossberg 500/590, this is the go-to option. You can find the product page for the Mesa Tactical LEO Gen II Tele Stock Kit with all the options here.
FAQ (Quick Answers)
- Will it fit my Mossberg 500/590? Yes, it’s designed specifically for these models (12- or 20-gauge).
- Do I need a gunsmith? Nope. User-installable.
- How much recoil reduction can I expect? Mesa claims 70–90% – in my testing, I’d have to agree, depending on load and damping setting.
- Does the kit include a stock and grip? Some SKUs are adapter-only; SKU 90020 includes the KynSHOT buffer and hardware.
As always, I’d like to thank Mesa Tactical for sending their LEO Gen II Telescoping Stock Adapter with the KynSHOT buffer for my testing and evaluation. It’s a solid bit of gear that performs as advertised.