[INSANE] 50 BMG Full-Custom Build Kick-Off!

I’ve been wanting a 50 BMG for 10 years. I originally planned content around an OEM rifle, but now, I get to build one!  


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About the Build 

This build kicks off our 50 BMG content series. 50 BMG is just loud and fun, but it also opens up the door to ELR. I recently got to know Paul Phillips, King of 1 Mile and King of 2 Miles, and he’s going to be mentoring me in ELR. Following this build, I’m planning on getting a different bolt and barrel, probably for 375 Cheytac, and planning out a more serious ELR rifle. 

At the center of this build is BAT Machine’s EX action. This massive action measures 12 inches in length and weighs approximately eight  pounds. For 50 BMG, everything is BIG. Even the dimensions of the action wrench are comical. 

This action will be set in the Accurate Rifle Systems ELR chassis with the BipodeXt. This telescopic bipod extends to over 40 inches! 

The chassis is currently in the white in preparation for blasting and Cerakote. I don’t have a full plan worked out, but I do know it will involve some special colors and possibly some laser imaging

Lifting the International Barrels’ 50 caliber 1:15 barrel blank is a workout in and of itself. I’ll be chucking this up in the Precision Matthews TL-1660 lathe. This lathe has a 2.5” through-spindle capacity. The barrel diameter is 1.75” at the shank, so we have plenty of room. 

I’ll be using Triebel tooling, including a 50 BMG body and neck reamer, throater, go gauge, no-go gauge, and freebore gauge.

With these tools, I can choose the freebore I desire and custom tune the gun to the bullets I choose. I’m working with Bruce Thom from BAT Machine on some recommendations. 

50 BMG Reamer in Rigid Reamer Holder, Precision Matthews TL1660 Lathe

I’m also using my own custom-made rigid reamer holder (Morse Taper #4) for this build. It is so precisely machined that removing the reamer is accompanied by a satisfying air pop. Putting it back in results in an air seal without an O-ring. Stay tuned for a separate video on how I did it! 

50 BMG Rigid Reamer Holders

Though I typically use Short Action Customs barrel vises, for this project I’m using my Brownells barrel vise. This vise has a 1.75” bushing diameter. My plan is to remove the bushing and put some rosin in.

On the muzzle end, we have the APA Gen 2 XXX Bastard brake. This brake has a nut for self-timing and is threaded 1”x14.


Looking forward, I may also be testing an AccuTac bipod as well as a Phodera Suppressor (20 inches long!) on this gun. This passion project has been a decade in the making and I’m looking forward to all it has to offer. One thing I am particularly excited about is shooting tracer rounds across the canyon in the snow (to prevent fires). Stay tuned for the rest of this series, featuring the barrel work, custom Cerakote, barrel break in, and more! 

Get the Gear

BAT EX Action 

Accurate Rifle Systems ELR Chassis 

Accuracy Solutions BipodeXt

Triebel Reamers and Gauges

Brownells Barrel Vise

APA Gen 2 XXX Bastard brake

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Gavin Gear

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