If you are interested in putting together the ultimate light Extreme Long Range (ELR) rifle, this is the build for you. The 300 Norma Mag takes something like a 300 PRC and bumps it up to that next level of performance, making it increasingly popular in the light ELR class. In this video, we cover the complete formula for parts and components, the chambering process, assembly, and breaking the rifle in. 

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Bill of Materials

I selected all materials with the goal of maximizing ELR performance while utilizing a modern, highly adjustable chassis system.

I began with the BAT Hammerhead long-action, which features a remarkably fast 75-degree bolt throw in a Remington 700 footprint.

To this, I mated a Custom Rifle Barrels (CRB) 31” finished straight blank. While CIP specs for .300 Norma suggest a 1:9 twist, I opted for a 1:8 twist to optimally spin the heaviest modern .30 caliber bullets.

This barreled action rests perfectly in the Accuracy Solutions Baby Orca Chassis. (Use code UR10 to save 10%!) This unique chassis is made from Micarata and features an integrated bipod extender, allowing the bipod to sit closer to the bore axis. It also boasts an incredible micro-adjustable buttstock for ultra-fine elevation control on the rear bag.

For the trigger, I went with my go-to precision setup: the TriggerTech Remington 700 Diamond, adjusted down to a crisp 7 ounces.

For optics, I mounted the Telson Targetmaster Victory 5-32×56 FFP scope inside a rugged Hawkins Precision Heavy Tactical one-piece mount.

An MDT .338 Lapua length magazine handles feeding, and the muzzle is topped with the Area 419 Maverick Gen 2 suppressor mounted via a Sidewinder adapter.

Machining and Assembly

Using the Precision Matthews PM-1440-HVT-2 lathe, the chambering process was incredibly smooth. The rigid CRB blank dialed in to within two ten-thousandths on the bore. I used a Manson finisher reamer alongside Manson go/no-go gauges to set the headspace perfectly.

I chose to thread the muzzle to 3/4×24. This leaves plenty of meat on the barrel before attaching the suppressor adapter, ensuring maximum integrity where the bullet exits the crown.

Once torqued to 75 ft-lbs. and engraved, the barreled action and TriggerTech trigger sandwiched flawlessly into the Baby Orca chassis. No traditional bottom metal is required for this chassis, and the MDT magazine locked in tight once the internal chassis spacer was removed.

About the PM-1440-HVT-2

The Precision Matthews PM-1440HVT-2 is a great gunsmithing lathe, with the following stand-out features:

• All Taiwanese built with Japanese spindle bearings
• 2.055″ thru-spindle capacity
• Available cast iron ultra-rigid base
• Variable Speed drive
• 14” Swing, 40” Between Centers
• D1-5 Chuck Mount
• MT3 Tailstock Taper 

If you’d like to know more about the PM-1440HVT-2, check out our full overview HERE.

Building the Load: Peterson Cartridge Brass

When building a cartridge designed to push extreme distances, brass is the foundation of your precision. After touring the Peterson factory and talking with owner Derek Peterson, their 300 Norma Mag brass was the obvious choice.

Using the Redding Ultramag press and new 1-inch dies, the Peterson brass performed phenomenally. Their proprietary “EZ Seat” coating and perfectly dimensioned case necks made seating bullets exceptionally smooth.

For the break-in process, I loaded up a conservative charge of 79.0 grains of Retumbo pushing 230-grain Hornady A-Tip bullets, leaving roughly 0.020″ of jump to the lands.

Initial Range Results

Bore-sighting was a breeze thanks to the fine micro-adjustment wheel on the Baby Orca’s rear bag rider. Right out of the gate, the first three-shot sight-in group measured a phenomenal 0.274 inches—right around a quarter MOA!

I followed this up with a five-shot group that measured 0.489 inches.

It opened up slightly vertically, which I attribute entirely to my shooting position (firing off skis on an uneven dirt slope) rather than any limitation of the rifle or the Peterson brass.

Conclusion

Overall, I am incredibly impressed with this entire package. From the rigidity of the BAT Hammerhead action to the adjustability of the Baby Orca and the consistency of the Peterson brass, this rifle is an absolute laser.

Get the Gear

Accuracy Solutions ORCA Chassis System (Use code UR10 to save 10%) 

Bipod eXt (Use code UR10 to save 10%)

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Thanks,
Gavin Gear