The KNS Precision Adjustable Gas Piston System Wz89 Onyks is a direct retrofit solution for AK-platform rifles that come overgassed from the factory. If you've noticed your brass flying 15+ feet downrange, or you're tired of accelerated wear on your bolt carrier and receiver, this adjustable gas piston lets you dial in the exact gas flow your rifle needs—without a gunsmith visit or special tools. The system works with your existing gas block and installs in about 10 minutes, so you can get back to the range fast.
AK-type rifles are legendary for reliability, but their gas systems often run hotter than necessary. That excessive pressure speeds up wear on critical parts and can make shooting less pleasant. The KNS Precision solution is straightforward: swap the piston, adjust the regulator to your ammo and setup, and run only the gas you actually need. This extends the life of your rifle and gives you tighter shot groups and softer recoil impulse.
The Wz89 Onyks is available in two configurations: a small-caliber piston for .223 Rem., 5.56 NATO, and 5.45x39mm, and a large-caliber piston for 7.62x39mm, .308 Win., and 7.62x54R. It's designed to fit AKM, AK-74, VEPR, PSL, and M92 rifles. Because adjustment is tool-free and intuitive, you can fine-tune gas flow on the fly at the range, dialing it down until your rifle cycles reliably with the round you're shooting.
Whether you're running corrosive surplus ammo, hand-loads, or commercial factory rounds, an adjustable gas system puts you in control. The KNS Precision Wz89 Onyks is the smart way to keep your AK running cleaner, cooler, and longer.
Key Features
- Adjustable regulation—dial in the exact amount of gas your rifle needs
- Works with your existing gas block; no modifications required
- Two piston configurations: small-caliber (.223/5.56/5.45x39) and large-caliber (7.62x39/.308/7.62x54R)
- Compatible with AKM, AK-74, VEPR, PSL, and M92 platforms
- Installs in approximately 10 minutes with no gunsmith needed
- Reduces wear on bolt carrier, receiver, and other moving parts
- Tool-free adjustment for field tuning
Specifications
| Brand | KNS Precision |
| Product Type | Adjustable Gas Piston System |
| Model | Wz89 Onyks |
| Piston Options | Small-caliber or Large-caliber |
| Small-Caliber Calibers | .223 Rem., 5.56 NATO, 5.45x39mm |
| Large-Caliber Calibers | 7.62x39mm, .308 Win., 7.62x54R |
| Compatible Rifle Types | AKM, AK-74, VEPR, PSL, M92 |
| Installation Time | Approximately 10 minutes |
| Gunsmith Required | No |
Frequently Asked Questions
Which piston do I need for my caliber?
Choose the small-caliber piston if you're shooting .223 Rem., 5.56 NATO, or 5.45x39mm. If your rifle is chambered in 7.62x39mm, .308 Win., or 7.62x54R, select the large-caliber piston.
Will this work on my AK rifle?
The KNS Precision Wz89 Onyks is compatible with AKM, AK-74, VEPR, PSL, and M92 rifles. It uses your existing gas block, so no permanent modifications are needed.
Do I need a gunsmith to install it?
No. The system is designed for do-it-yourself installation in roughly 10 minutes with standard tools. You do not need a gunsmith.
How do I know if my AK is overgassed?
Fire a few rounds at the range and observe where your brass lands. If it's consistently hitting the ground more than 15 feet away, your rifle is running too much gas and would benefit from adjustment.
