March 5th, 2017

Big Boomer Load Dev — .375 Caliber 400 Grainers at 3290 FPS

.375 Lethal Magnum Big Boomer KO2M Paul Phillips Applied Ballistics
Serious ammo — .375 Lethal Magnum rounds loaded with 400gr Cutting Edge Lazer bullets. One wag posted “They look like SCUD missiles.”

In the Extreme Long Range (ELR) game, great ballistics are paramount, but you also need excellent accuracy. The top ELR shooters campaign large-caliber rifles that boast truly remarkable accuracy, considering the massive cartridges they’re shooting (with 160+ grains of powder). These big boomers, such as the .375 Lethal Magnum shown above, can really hammer.

The winner of the 2016 King of 2 Miles (KO2M) event was Mitchell Fitzpatrick, shooting a .375 Lethal Mag cartridge, as part of Team Applied Ballistics. Another member of that squad, Paul Phillips, is also campaigning a new rifle chambered for the .375 Lethal Magnum. Paul was recently doing load development for his new beast, which features a McMillan stock, Nightforce scope, and Phoenix Bipod. Among his barrels for this rig is a massive, 38″-long Bartlein.

.375 lethal magnum

“I had a great time today doing load development at Applied Ballistics LLC laboratory with Bryan Litz, Bill Litz, and Mitchell Fitzpatrick. I was testing loads for my .375 Lethal Mag built by Lethal Precision Arms LLC. The last several test groups were sub half-min at 300 yards. Next testing is at 1800 yards.” — Paul Phillips

For this test, Paul’s load featured 400gr Cutting Edge Lazer bullets launched at a blistering 3290 FPS with Hodgdon H50BMG powder. Looks like Paul got his load dialed in “good and proper”. He fired a 0.9″ group at 300 yards, and the Oehler System 88 chronograph showed a very low Extreme Spread (ES) of just 5 FPS. That’s impressive even for just three shots.

A little snow on the ground can’t stop the Applied Ballistics testing team…
.375 Lethal Magnum Big Boomer KO2M Paul Phillips Applied Ballistics

Look carefully and you’ll find the powder charge weight — a bit more than you’d load in a 6PPC…
.375 Lethal Magnum Big Boomer KO2M Paul Phillips Applied Ballistics

Bryan Litz inspects the .375-caliber barrel with bore-scope.
.375 Lethal Magnum Big Boomer KO2M Paul Phillips Applied Ballistics