Modulus Arms

The modulus jig gives me the best finish on 80% lowers and I've done at least 50 lowers. There is no comparison. It takes me about 1.5 hours to do a lower with the modulus system. It would take me a out 3.5 hours with other jigs on a mill. I use a Makita router so simple.

Great service as usual ! Arrived quickly & package well ! Website is easy to use & order from ! Thanks

Just got my jig and have completed my first 80% receiver., I’m ordering another router bit to replace mine in case it dulls, breaks or wears out. I have finished several other lowers using all sorts of jigs and devices but this is by far the simplest and moves yet! It is easy to set up and use with the exception of the very beginning. My router (the Bosch) does not adjust far enough up to start the cut.. but I made do! It can be done! But is NOT designed to be used with the motor that far away from the material.. my only complaint! I’m considering a cut shorter router bit to do my initial cuts with then finish with the speedmill bit…

The jig is everything that it claims to be.

Great jig for building my AR’s. Simple to use and the results are perfect. Best part for me is it’s red!