SAG MK4 Chassis – 5-Slot with Rear Sight Cutout
- $1 349.00
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Available Options
SAG MK4 Chassis – 5-Slot with Rear Sight Cutout
CNC-Machined Aluminum | Free-Floating Barrel | 1913 Top Monorail | Integrated Gas Tube Upper | Rear Sight Cutout | Reusable
The SAG MK4 Chassis by Sureshot Armament Group is a complete solution for mounting lighting and optic devices on a sporting platform without any modification to the original carbine. The MK4 consists of the MK1 handguard block plus an upper with an integrated gas tube and the removable rear cover from the MK3 chassis.
Once installed, the chassis free-floats the barrel inside a tubular handguard and provides a 1913-MIL-STD top monorail over the barrel and receiver, from the gas block to the end of the shortened cover. The rear sight cutout preserves the factory rear sight. The front rail section does not require removal for field-stripping, the stock still folds completely, and the iron sights are not blocked. The removable rear cover section carries its own 1913 segment for optics that don't need to retain zero (magnifier, NV attachment).
? Select the Correct Platform Version
The MK4 Chassis is produced in three platform-specific variants, each machined for a different receiver geometry. These versions are not interchangeable. Please select the variant matching your platform using the Platform Version selector above:
- AK-Pattern version (SKU SAG-S20131)
- Saiga-308 version (SKU SAG-S20191)
- VPO / Molot version (SKU SAG-S20192)
Already own an MK1 handguard? An upgrade kit (upper + rear cover only) is available as a separate product.
? Key Advantages
- Free-floats the barrel – inside a tubular handguard
- 1913 top monorail – gas block to shortened cover, for optics and lighting
- Integrated gas tube upper – MK1 handguard + MK3 rear cover architecture
- Rear sight cutout – retains the factory rear sight
- No removal for cleaning – front rail stays on during field-stripping
- Folding-stock compatible – stock folds fully for transport
- Removable rear cover rail – for magnifier or NV attachment
- Reusable – can be reinstalled on a new carbine
Technical Specifications
| Material | High-Strength Aluminum Alloy (CNC-milled) |
| Product Codes | SAG-S20131 (AK) / SAG-S20191 (Saiga-308) / SAG-S20192 (VPO·Molot) |
| Architecture | MK1 handguard block + integrated gas tube upper + MK3 removable rear cover |
| Top Rail | 1913-MIL-STD monorail, 5 slots (gas block to shortened cover) |
| Rear Sight | Rear sight cutout – retains factory rear sight |
| Rear Cover Rail | 1913-MIL-STD segment (removable section) |
| Barrel | Free-floating inside tubular handguard |
| Reusable | Can be reinstalled on a new carbine |
Compatibility
Available in three platform-specific variants (select above). See the compatibility filter on this page to confirm fitment for your specific platform.
Important: This chassis is not suitable for self-installation on full-size carbines built on certain Molot Arms AKM-pattern receivers (MA-136-02, MA-136C, MA-136-05). For those platforms, installation must be performed in a gunsmith workshop.
What's Included
- (1) SAG MK4 Chassis (selected platform version, complete)
- (1) Mounting Hardware Set
- (1) Installation Manual
FAQ
Q: What is the MK4 made of?
A: It combines the MK1 handguard block with an upper that has an integrated gas tube, plus the removable rear cover from the MK3 chassis.
Q: Does it keep the factory rear sight?
A: Yes – this version has a rear sight cutout that preserves the factory rear sight.
Q: I already have an MK1 handguard – do I need the full chassis?
A: No – an upgrade kit (upper + rear cover only) is available as a separate product to convert your MK1 into a full MK4.
Q: Do I need a gunsmith?
A: For most platforms, no. Certain Molot Arms AKM-pattern full-size carbines require a gunsmith workshop.
Q: How does shipping work?
A: US orders are fulfilled and delivered through our partner's domestic US logistics network. Delivery is not express, but it is reliable and fully guaranteed.
Free-Float Your Platform, Keep Your Irons
? In Stock ? Guaranteed US Delivery ? CNC-Machined Quality
SAG Specs
General
Recommended
SAG, Sureshot Armament, MK4 Chassis, Chassis, 5-Slot, Rear Sight Cutout, Free-Float, 1913 Rail, Gas Tube Upper, Chassis Systems, Bazalet