SHTF50 Mag Fed .50 BMG Upper Assembly — 18", 22" or 29"

50 BMG

SHTF50 Mag Fed .50 BMG Upper — 22" or 29" (FFL Transfer Required)

The SHTF50 Mag Fed upper assembly converts any mil-spec AR-15 lower into a purpose-built .50 BMG bolt action style rifle using a detachable magazine. Machined from premium chromoly steels and engineered for durability, the SHTF50 delivers extreme long-range performance in a compact, user-serviceable package. Available in 18", 22", or 29" barrel lengths to match your use case—shorter barrels for portability, longer barrels for maximum velocity and long-range ballistics.

Important legal notice: A July 2018 BATFE determination classifies SHTF50 upper assemblies as firearm receivers. All SHTF50 orders must transfer through a licensed Federal Firearms Licensee (FFL). See FFL instructions below.

What’s Included

• One (1) SHTF50 Mag Fed upper assembly (select barrel length: 18", 22", or 29")

• One (1) hammer and spring to replace AR-15 hammer and spring

• One (1) 5-round magazine

Note: AR-15 lower is not included.

Key Specifications

• Caliber: .50 BMG

• Receiver: Machined from 4130 Chromoly steel

• Bolt Body: Machined from 4130 Chromoly tubing

• Bolt Head: 2-lug, machined from 4340 Chromoly steel

• Barrel Material: 4140 Chromoly steel, button rifled

• Barrel Lengths Available: 18", 22", 29"

• Rifling / Twist: 1:15 RH

• Muzzle Device: 8-port steel muzzle brake, threaded to muzzle

• Feed: Detachable 5-round magazine (included)

• Scope Mount: Aluminum Picatinny rail mounted to receiver

• Finish: Factory finish per production run

Measured Muzzle Velocities (average of 3 shots)

• 18" Barrel: ~2283.6 fps

• 22" Barrel: ~2385.9 fps

• 29" Barrel: ~2561.9 fps
  Test conditions: 90+°F, 85% humidity, Summit/French Reloaded M33 Ball, chronograph at 20 ft.

Weight (upper assembly only)

• 18" Barrel: ~12.0 lbs

• 22" Barrel: ~12.5 lbs

• 29" Barrel: ~15.5 lbs
  Weight does not include the AR-15 lower.

FFL and Shipping Instructions (READ BEFORE PURCHASING)

• FFL Transfer Required: Per BATFE determination, SHTF50 upper assemblies are treated as receivers and must transfer through a licensed Federal Firearms Licensee (FFL).

• How to provide FFL info: During checkout, enter your FFL dealer’s information in the shipping address field OR add the FFL contact and license details in the order notes/comments.

• Processing requirement: We will not process or ship your order until we receive a signed copy of the FFL that references your invoice number. Email FFL documentation to the address shown at checkout or as instructed on your invoice.

• We will only ship to the licensed FFL dealer’s address. Verify your dealer accepts incoming transfers for this product.

• Customer responsibility: Confirm compliance with federal, state, and local laws prior to purchase. Moriarti Arms will not ship to jurisdictions that prohibit these items.

Additional Notes & Safety

• AR-15 lower receiver is required to complete a functioning rifle; it is not included.

• Due to the powerful cartridge and custom nature of this product, use only quality match or recommended ammunition and follow safe handling and shooting practices.

• Ballistics and cycling may vary by ammunition, environmental conditions, and barrel length.

• Images and finishes may vary slightly from production units.