Oversized bolt handles allow shooters rapid bolt manipulation, positive control, and greater clearance from the rifle’s optic.
After market bolt knobs come in two basic configurations; those that require the old knob be turned down into a threaded stud and those that remove the factory knob, drill a hole and install a stud to accept the knob. For this project, we will utilize the utilize the first kind.
Here we install a Brownells oversized bolt handle on a Remington 700 SPS using our Grizzly 4003G lathe.
We utilized the following tools for this project from Brownells:
We also ordered a bolt handle threading fixture from Pacific Tool and Gauge.
This project documents our experience attaching an oversized bolt knob, we take extreme caution and follow all relevant safety procedures when operating our lathe.
Here is our stock bolt handle with the replacement handle. The replacement handle has female threads inside of it. The factory knob will be milled down into a threaded shank to receive the larger, aftermarket handle.
These are the tools we are going to use on our lathe to replace the bolt handle. PTG angled bolt handle threading jig (top), carbine cutter (center left), #2 center drill (center right) and a 5/16″x24 die and die stock (bottom).
We utilize a bolt disassembly tool to remove the firing pin assembly from the bolt body before work securing the bolt in the lathe.
The bolt disassembly tool is slid over the rear of the bolt.
Engaging the lever, the firing pin is retracted.
With the firing pin retracted, the assembly can be unscrewed from the bolt body.
We mount the PTG jig into our three jaw chuck and secure the bolt handle in the fixture with a piece of brass shim stock. At this point, we can still adjust the positioning of the bolt handle.
We mount the #2 center drill in the lathe’s tail stock and align it with the proper location on the bolt handle. Once the handle is aligned, we tighten the handle in place and then center drill the knob. CAUTION: the bolt body extends past the fixture and requires the utmost in care to avoid harm to the lathe operator.
With the handle center drilled, we move our live center forward. The work is then cut from the fixture (or front of lathe) towards the back. Since this is an interrupted cut, we take light passes. Care must be taken; if you are too quick, you may snap the handle off of the bolt body.
We progress along, checking the diameter of the tenon as we go. Ample cutting oil is used, in this case, Viper’s Venom.
Once the major diameter of our 5/16×24 thread is reached, the tool post is retracted and the live center removed.
There are a few options to thread the tenon on the handle. We decided to use a die and die stock. Notice the back side of our die and die stock is flush.
The flat face of the die and die stock are placed against the flat face of our chuck mounted in the lathe. Light pressure is then applied to the chuck with the tail stock and the die stock is rotated by hand. This ensures the die cuts perpendicular to the axis of the tenon. Once the die is turned a few times, we proceed to thread the length of the tenon.
With the thread complete, we unscrew the die and remove the bolt handle from the fixture.
A quick test fit of the bolt handle shows our installation was successful
A little bit of Acraglas epoxy on the threads and our Brownells tactical oversized bolt handle is ready for the range.