This jig is compatible with our Forged 80% Lowers. Our Premium Fire/Safe Marked Billet 80% Lowers are not compatible with this 80% lower jig. Other manufacturer's billet 80% lowers may compatible with this 80% lower jig, provided their lower receiver design adheres to mil-spec specifications.
Most 80% jigs are made of precisely-machined alloys, made rugged enough to cut and drill lower after lower. If you’re the once-and-done builder (or you’re working on a tight budget), you’re probably looking for something simpler. Maybe you just want to try out gunsmithing at home and don’t want a big sunk cost. We get it. That’s why we partnered up with our friends at Polymer80 to offer you a new disposable, universal AR-15/AR9 80 lower jig!
The RJ556U jig is made from reinforced polymer and ships with the necessary drill bits and end mill bit to cut and drill any mil-spec AR-15 or AR9 80% lower receiver. This jig’s tough nylon composite allows it to reliably machine polymer and forged or billet aluminum receiver blanks - up to three with the original tooling. All for a super-low price.
The RJ556U Jig Includes:
- (1) Left and Right Side Plate
- (3) Trigger Template Guides
- (1) 9mm HSS End Mill
- (1) 5/16 Drill Bit
- (1) ⅜ Drill Bit
- (1) 5/32 Drill Bit
Cutting and Drilling with The Jig
The RJ556U Jig doesn’t require an expensive mill to operate. All that’s required to use the jig is a standard drill press and some basic measuring devices:
- Vise For Drill Press - 6” jaws
- Drill Press -1850-2250 RPM
- Digital Calipers
- Dremel Bit #9904
- Bubble Level
- Round Machinists File
- Non-marring Vice Jaws
- Lower Receiver Vice Block
- Upper Receiver Vice Block
Learn how to cut and drill your receiver blank by downloading Polymer80’s written instructions here.
Shipping of various parts and/or accessories are prohibited to states and locales (ie New Jersey, California, New York, etc…) with restrictions against certain parts and/or accessories or “assault weapons” (i.e. states with high-capacity magazine restrictions, manufacturing of semi-automatic weapons, etc..). It is your responsibility to be aware of your local firearms laws before purchasing from our website or machining a firearm. We try our best to keep our shipping page current, but laws change daily
80-Lower.com only ships within the United States. Federal legislation dictates we cannot ship our products internationally.