Description
Builder's Grade Complete 16" Upper Receiver | 12" Slant Cut M-LOK | BCG & CH:
This Complete 16 inch M-LOK upper receiver comes with our RTB 12 inch free float Slant cut handguard and is built with only the best Mil-Spec components. The heart of this upper is comprised of a 4150 barrel and our black nitride bolt carrier group that is finished with an incredible polish, making the action smooth and easy to keep clean.
Barrel
Specifications
Caliber 5.56
Length 16"
Material 4150 Chrome Moly Vanadium
Profile M4
Finish QPQ Corrosion Resistant
Gas System Length Carbine
Gas Block Journal .750"
Dimpled? No
Twist Rate 1:7
Muzzle Thread 1/2x28 TPI
Weight 27.2oz
Barrel Extension M4 Feed Ramps
Target Crown 11 Degree
OR
Barrel
Specifications
Caliber 300 BLK
Length 16"
Material 4150 Chrome Moly Vanadium
Profile Medium
Finish QPQ Corrosion Resistant
Gas System Length Pistol
Gas Block Journal .750"
Dimpled? No
Twist Rate 1:7
Muzzle Thread 5/8x24 TPI
Weight 29.6oz
Barrel Extension M4 Feed Ramps
Target Crown 11 Degree
Bolt Carrier Group:
Enhanced 9310 Steel (Bolt)
8620 Tool Steel (Carrier)
Bolt is shot Peened and MPI
All BCG components are pre-polished before being processed and then post polished for an incredible shine
Upper Receiver:
Machined from a Mil-Spec 7075 T6 forging Hard Coat Anodized per Mil-A-8625F, Type III
M4 Feed ramps
Made in the U.S.A.
Handguard:
12" free float handguard
MIL-STD 1913 Picatinny rail on top
4 M-Lok slots on 3 sides
Precision Machined 6000 Series aluminum, for high strength and weight savings
Clamp on system for easy assembly
Steel Barrel nut to resist movement under heat
Made in USA
Charging Handle:
Alloy Charging Handle Assembly
Complete with Standard Latch
Made from hardcoat anodized aluminum
Black finish
Tactical Sport 6-Position M4 Stock Kit:
This polymer stock is made from impact-resistant, high-strength material.
Mil-spec Diameter Extension Tube Made from Aircraft Aluminum with Rolled Threads
Built for Heavy-duty Operations with Tightest Tolerance Control
Stock Assembly Complete with Action Spring, Buffer Assembly, Tear-drop Ring, and Castle Nut
Bare Necessities Complete AR15 LPK:
This BN Lower Parts Kit is what you need to build a custom AR15 from the ground up. Mil-spec dimensions and coating ensure the highest quality and correct component interface.
Safety Selector
Selector Spring
Selector Detent
Magazine Catch
Magazine Catch Spring
Aluminum Magazine Catch Button
Bolt Catch
Bolt Catch Detent
Bolt Catch Spring
Bolt Catch Roll Pin
Take Down Pin Take Down Detent
Take Down Detent Spring
Front Pivot Pin
Front Pivot Pin Detent
Front Pivot Pin Detent Spring
Trigger Guard
Trigger Guard Roll Pin
Buffer Retainer Detent
Buffer Retainer Spring
A2 Pistol Grip
Pistol Grip Screw
Pistol Grip Lock Washer
Trigger
Trigger Spring
Hammer
Hammer Spring
Disconnector
Disconnector Spring
Hammer Pin & Trigger Pin
***Disclaimer: This made-to-order product may include minor component substitutions of military-specification quality or better. These changes, potentially differing cosmetically from shown images, ensure enhanced quality and performance. This may include ambidextrous sling loop endplates or an upgraded extra power spring.
SKU: BG1655612SL-BLK-IBOR-FULL-LPK-TS

Bought a similar "Builder's Grade" kit recently from RTB that had burrs and metal fillings around the locking lugs which impeded the action until cleared. It ended up being fine after cleaning it thoroughly. Just know what you're getting for the price and do the extra work to inspect and such. Don't assume it's range ready out of the box.