Completing an 80% 10/22 Select Fire LLC RAZOR Semiautomatic Receiver

July 1, 2013 Bill Marr Gunsmithing 0

Here is our completed RAZOR. Once the parts are test fit, we will finish in Cerakote and assemble into a complete rifle.
Here is our 80% RAZOR receiver as supplied by Select Fire LLC. This is milled from a billet of 6061-T6 aluminum.
Here is our 80% RAZOR receiver as supplied by Select Fire LLC. This is milled from a billet of 6061-T6 aluminum.

Machining an 80% 10/22 Receiver, Completing a Select Fire LLC RAZOR Semiautomatic Receiver

The Ruger 10/22 has become the ubiquitous semi automatic 22 rifle of this generation.  Its modular construction and wide range of aftermarket parts have made it the gun customizer’s dream.  In addition to the original Ruger 10/22 receivers, a number of companies offer aftermarket receivers with enhanced features. In this case, we are going to complete a Select Fire LLC RAZOR 80% receiver.  This 10/22 style receiver, includes an extended optical mounting rail machined into its top.  Note: even though the company that produces this receiver is called Select Fire LLC, the rifle we are constructing for our own use is a semi automatic.

If you aren’t familiar with them, 80% receivers are receiver blanks machined short of what the ATF would consider a firearm.  This allows individuals to purchase and complete them, where legal, for their own personal use, without the need of transferring the item through an FFL.  Prior to proceeding with a project like this, check out the BATF’s website to make sure what you want to do is in compliance with all applicable federal and local laws.

After much debate on the methods we could use to complete the receiver- using either a minimalist approach or more conventional machine shop methods- we decided to go the machine shop route.  This was mostly because we were very impressed with the quality of the RAZOR when we received it and wanted the best possible final product.  If you don’t have access to a machine shop and want to complete a project like this, no worries.  Select Fire LLC offers a tool kit and drilling guide that allows you to complete an 80% RAZOR with a regular hand drill. Either method works and will provide a functional final product.

The drill kit and guide
The drill kit and fixture for the RAZOR

The RAZOR 80% receiver is available in both unfinished aluminum and an anodized black finish, with both short and extended rails.  We selected the extended rail unfinished model since we plan on Cerakoting it.  If you aren’t equipped to coat the receiver, we would suggest getting the anodized model.  Anodizing is a hard finish and in many ways superior to any of the spray on finishes available to most.

A few notes on completing a project like this:

  1. Aluminum can be difficult to work with since it has a low lubricity.  Make sure you use appropriate cutting fluid and the correct RPM for your drills.
  2. Measure twice and take your time.  We used the digital read out (DRO) on our milling machine to locate the holes.  This could also be done with the drilling fixture available from Select Fire LLC or the with layout fluid, a scribe and calipers.
  3. Take the time to deburr the parts.  We used a deburring tool when we initially received our RAZOR to remove sharp edges.  220 grit abrasive cloth works well too.  We used abrasive cloth to remove any burrs we raised from the machining we completed when we were done.

The following is presented for information purposes only and should not be constructed as instructional advise.  Additionally, check the BATF’s website prior to completing your own RAZOR to make sure you are in compliance.

Select Fire LLC provided the following:

In addition to the RAZOR 80% receiver supplied by Select Fire LLC, we used to following tools and supplies from Brownells:

 

We decided to start our project by drilling the barrel hole. We secured the RAZOR receiver in our milling machine vise against an angle plate.
We decided to start our project by drilling the barrel hole. We secured the RAZOR receiver in our milling machine vise against an angle plate.
To drill the barrel hole, we use a spotting drill to locate the center of the barrel hole.
To drill the barrel hole, we use a spotting drill to locate the center of the barrel hole.  We locked the mill in the X and Y axis prior to drilling.
The barrel hole will be drilled in a series of steps. We start with a 1/4" drill, move to a 3/8", 1/2", 5/8" and finish with a boring bar. Lubricant is essential. We used Tap Magic, which worked well for our application.
The barrel hole will be drilled in a series of steps. We start with a 1/4″ drill, move to a 3/8″, 1/2″, 5/8″ and finish with a boring bar. Lubricant is essential. We used Tap Magic, which worked well for our application.
As the hole sizes increase, your RPMs need to be lower to the appropriate speed.
As the hole sizes increase, your RPMs need to be lowered to the appropriate speed.
We finish the barrel hole with a boring bar. As we reach the target diameter, we take lighter cuts to ensure a smooth finish.
We finish the barrel hole with a boring bar. As we reach the target diameter, we take lighter cuts to ensure a smooth finish.
While the receiver was secured vertically, we decided to drill the two barrel hold down bolt holes. A #16 drill is used to drill completely through the piece after the location has been spotted.
While the receiver was secured vertically, we decided to drill the two barrel hold-down bolt holes. A #16 drill is used to drill completely through the piece after the location has been spotted.

 

After the #16 bit, a 1/4" drill is sued to drill a .700" deep counterbore to provide clearance for the barrel hold down screw shank.
After the #16 bit, a 1/4″ drill is used to drill a .700″ deep counterbore to provide clearance for the barrel hold down screw shank.

 

A 1/4"x24 two flute tap, supplied by Select Fure LLC, lubricated with Tap Magic, makes short work of threading the two barrel hold down bolt holes.
A 1/4″x24 two flute tap, supplied by Select Fire LLC, lubricated with Tap Magic, makes short work of threading the two barrel hold-down bolt holes.
Here is the barrel hold down, secured in place.
Here is the barrel hold-down, secured in place.
A #16 drill is used to drill a hole for the stock screw.
A #16 drill is used to drill a hole for the stock screw.
The two flute 1/4"x24 tap is used to thread the stock hold down screw.
The two flute 1/4″x24 tap is used to thread the stock hold down screw.
With the receiver secured on a set of parallels, the front and bottom edge of the receiver are located and zeroed in the mill's DRO. Two 3/16" holes will be drilled for the trigger pins, and one 1/4" hole for the bolt stop pin. We decided to drill each of these holes from each side, rather then through to prevent the drill from walking. Prior to drilling, a #2 center drill is used to ensure the drill does not wander.
With the receiver secured on a set of parallels, the front and bottom edge of the receiver are located and zeroed in the mill’s DRO. Two 3/16″ holes will be drilled for the trigger pins, and one 1/4″ hole for the bolt stop pin. We decided to drill each of these holes from each side, rather then through to prevent the drill from walking. Prior to drilling, a #2 center drill is used to ensure the drill does not wander.
The three holes drilled into the side of the receiver.
The three holes drilled into the side of the receiver.
The receiver is secured at a 3 degrees and the 5/16" long drill is used to drill a .250" deep magazine detent hole.
The receiver is secured at a 3 degrees and the 5/16″ long drill is used to drill a .250″ deep magazine detent hole.
The 1/16" aircraft drill provided in the drill kit is used to spot the rear of the receiver for the recoil guide rod.
The 1/16″ aircraft drill provided in the drill kit is used to spot the rear of the receiver for the recoil guide rod.
Here is our completed RAZOR. Once the parts are test fit, we will finish in Cerakote and assemble into a complete rifle.
Here is our completed RAZOR. Once the parts are test fit, we will finish in Cerakote and assemble into a complete rifle.
Here is our completed RAZOR. We are very happy with the results.
Test fitting the parts indicates everything works so far. We are very happy with the results.

This was quite a rewarding project.  If you are interested in learning more about the RAZOR receiver, visit Select Fire LLC.  

 

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