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MDT LSS Chassis System

MDT LSS Chassis was designed to be as compact as possible. The V-shaped bedding and free floated fore-end improve accuracy and ergonomics. The fore-end allows for barrel contours up to 1″ in diameter. The graphic on the right shows the 2 flat spots (V-block) where the action sits. The area below the action remains rounded for ultimate strength.

Picture of a MDT LSS Chassis System Installed on a Remington 700

MDT LSS Chassis System

The MDT LSS Rifle Chassis is manufactured out of billet 6061-T6 aluminum, and has been finished with Cerakote™ in Black or Flat Dark Earth (FDE).

To keep this chassis system compact, it was designed for collapsible AR-15 buttstocks, however fixed buttstocks can mounted with the use of a fixed stock adapter.
Alternatively, our LSS-XL chassis has a 3″ longer fore-end has was designed to accept fixed buttstocks without the use of the adapter.

See also the Brownells branded MDT LSS Bolt Action Chassis

MDT LSS Chassis System Compatibility

The MDT LSS chassis system is currently manufactured for the following bolt action rifle platforms:

  • Short Action Remington Model 700
  • Long Action Remington Model 700
  • Remington Model 7
  • Remington Model 783
  • Short Action, Savage, Models 10, 11, 12 and 16
  • Long Action,Savage, Models 110, 111, 112 and 116
  • Savage Axis – Short Calibers
  • Tikka T3 – Short Calibers
  • Tikka T3 – Long Calibers. Requires MDT 3.56 Magazine.
  • Mossberg MVP 5.56 (.223) using AR-15 Magazines
  • Mossberg MVP 7.62 (.308) using AR-10 Magazines
  • Howa 1500 / Weatherby Vanguard – Short Calibers. (Only compatible with MDT Polymer magazines)
  • Ruger M77 (Scout) Short Action
  • Ruger American – Short Action

Compatible Accessories for the MDT LSS Chassis System

The LSS chassis is designed to accept any AR-15 butt-stock and pistol grip (purchased separately), offering the option to customize from the wide variety of  Accessories available on the market.

The LSS chassis uses AICS style external box style magazines in .223 and .308 caliber for Short Action and .300WM or .338LM AICS style magazines for Long Action rifles, and supports installation of bolt on MIL-STN-1913 accessory mounting rails. Mounting holes are spaced for Magpul style L5 (11 slots) and L3 (7 slots) rails (1.600” / 3.200”) to be used on the bottom of the fore end up to 6.5″ in length.

Note: Long action magazines come in 3 different lengths: 3.715″, 3.775″ an 3.850″. Our chassis use 3.715 length magazines. The max thickness of recoil lug recommend is .350″ (8.9mm)

MDT LSS Chassis System Specifications

  • Increases accuracy by up to 21%
  • CNC Machined from 6061 aluminum
  • Cerakote Finish in Black or Flat Dark Earth
  • Hole spacing for Magpul L5(11slot) and L3(7slot)Rails
  • Designed for Collapsible AR-15 buttstocks
  • Accepts most AR-15 Pistol Grips
  • Lightweight, free-floating modular fore-end
  • Will accommodate barrels up to 1″ diameter.
  • Compatible with AICS style magazines in .223 or .308 (SA) and 300WM, 30.06, 338LM (LA). (Long Action Magazine length 3.715)
  • Weight: 1.6lb – 1.8lb

For rifles with longer barrels to be used for long range (past 900 meters) we recommend our TAC21 or our HS3 Chassis systems. The LSS chassis system comes as a 1-piece chassis, with all required mounting hardware included. This includes new action screws, and a screw for the pistol grip.

Note: To complete this chassis on your rifle, the additional items you need to purchase are:

  • Any AR-15 buttstock. For fixed buttstocks you will need the fixed stock adapter, or consider using our LSS-XL chassis.
  • A buffer tube for your buttstock. (Both milspec and commercial work on our chassis)
  • An AR-15 Pistol Grip. Ideally without a beavertail, or use a soft (bendable) beavertail.
  • At least one magazine

MDT LSS Chassis System Critical Details

Howa 1500 / Weatherby Vanguard Actions

This is the only action that we manufacture a chassis for, that has a flat bottom action. For this reason only our Polymer magazines will work. The fitting may need to be modified slightly for proper feeding.
For .223 models the bolt stop may be too long. This can easily be modified.

Savage models 10/110 11/111 12/112 16/116

For rifles with the bolt release at the bottom, the bolt release can be engaged through the side of the chassis, using a pin or tool. (Not included)

Tikka T3 – Long Calibers

Only our Metal 3.56 magazine will fit with the chassis for this action and needs to be purchased separately.

Savage Axis

The original recoil lug that comes with the rifle is required for installation into the chassis.

Ruger American and Ruger Scout

Both these actions have the action screw located directly above the magazine lever. This means that the magazine lever needs to be installed AFTER installing the action into the chassis. Detailed instructions are provided, and an installation video can be found here.

MDT LSS Chassis System Dimensions

Dimensions shown are based on Remington Model 700 Short Action. Note that this versions shows the use of the Skeleton Rifle Stock with a fixed stock adapter. So it can be shorted significantly using a carbine (collapsible) buttstock. If you prefer using a fixed rifle stock, take a look at the MDT LSS-XL chassis.

MDT LSS Chassis System Dimensions

MDT LSS Chassis System Dimensions





MDT LSS and HS3 Instruction Manual