Broken Arms 80% Lower Jig Review

By: Skipjack

Broken Arms 80% Lower Jig Review

By: Skipjack


I have always been curious about 80% lower recievers but it wasn't until a good friend introduced me to the the Broken Arms 80% Lower Jig that I really got locked on!

After a little researching online to see that my buddy was right about Broken Arm's jigs & tools being some of the most robust & by far the most user friendly of any 80% lower finishing product on the market! Furthermore, they have a full selection of bits any anything else you may need right on their website.

I used a Broken Arms 6061 billet lower receiver for my first 80% build & I'm glad that I did. This lower has a fixed trigger guard & a threaded bolt catch pin. The fact that you don't need any roll pins for this lower is almost reason enough to to buy it.

The jig fits together easy enough with indexing dowels for the take down pin holes and two hex bolts to snug it all together.

Please note that removing the lower receiver from the jig will take some wiggling and patience which, I don't think this is a bad thing as the tight fit gives me confidence that my machining will come out straight.

The various overlay plates are numbered in order of use and marked with depth values and bit diameter. The main plates have an integrated depth gauge on the side for easy access to the double & triple check before making a cut.  

The jig and plates fit together one way so even a Marine Grunt will have difficulty messing it up.

The jig is universal and while I have not tried any other billet lowers, I have completed several forged lowers from

In all cases, the components mated perfectly & produced clean cut complete lower receiver.

After purchasing the Broken Arms jig I still had a few questions and, thankfully, the Broken Arms website has a forum for trouble shooting & customer service.

If you have thought about finishing an 80% please watch Mike, the owner of Broken Arms, finish a lower on his drill press as well as give helpful hints & work arounds for customers on a budget. We will link to the video below!

Finally, this solid product is proudly made in America.

Get yours here:

Want more articles regarding 80% lowers? Post up in the comments below and suggest a product! Also, feel free to ask any questions as I may be able to save you some heartache

- Skipjack

Remember, disarming law abiding citizens does not keep them safe from criminals & safety is no accident.

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