This Sharps Bros builders kit provides you a Sharps Bros Hellbreaker Lower Receiver paired with a Rainier Arms Upper Receiver and Urban Combat Rail. This Kit will get you started on your next build. 

Hellbreaker Lower Receiver:

• Oversized integral trigger guards
• Beveled magazine flares
• A hard coat anodize finish per MIL-A-8625, the anodizing model for model for most military and aerospace products
• Full compatibility with all mil-spec internal parts
• Full compatibility with all other aftermarket mil-spec upper receivers
• Full compatibility with PMags, Hexmag and other standard capacity magazines
• Multi caliber mark
• Weight- 8.9oz

Rainier Arms A4 Forged Upper Receiver - GEN2

• Designed to fit our forged lower receivers with color, texture, & machining. These uppers are "T - marked" engraved and have extended M4 feed ramps.

Rainier Arms Urban Combat Rail - 15"

• Rail- 6000 series extruded Aluminum Milspec Type 3 Class 2 Hard Black anodized
• Barrel Nut- 7075 Aluminum  Type 3 Class 2 Hard Anodized
• 17-4PH  Cored Stainless Steel Rail mounting attachment- Patent Pending
• Anti rotate tabs time Rail to upper receiver
• No Barrel nut shims required for installation
• Does not contact or apply side loads to gas tube
• Inner Diameter of handguard - 1.315"
• MLOK Slots at the 3, 6 and 9 o'clock positions
• Includes barrel nut wrench
• Barrel Nut diameter- 1.378"
• Compatible with most known low profile gas blocks
• 11.9 oz. -Total weight including mounting hardware
• Made & Assembled in USA