Derek Rogers won the 2017 King of 2 Miles with this cartridge, and it has the performance to excel at Extreme Long Range, as well as manageable velocity migration which makes this cartridge a very attractive option for ELR. The 9.5x77mm (375 CheyTac) round is a good candidate, and Applied Ballistics has experience with this round. This is a requirement imposed by the military application intents for the round. In addition to the velocity migration issue, another design constraint was that the new cartridge had to be magazine feed-able with the best available bullets. So, somewhere between the machine gun rounds, and 375 Lethal Mag is where we wanted to be with the EnABELR. Rounds like this are made to fire and cycle for thousands of rounds in automatic and semi-automatic rifles so there can’t be any substantial velocity migration or other high maintenance issues for them. To begin the search for a cartridge that would produce low velocity migration, we considered rounds proportioned for use in machine guns such as the 7.62x51mm NATO (308 Winchester) or the 5.56x45mm NATO (223 Remington) as a baseline, near zero velocity migration. It’s hard enough to load ammo a consistent enough MV for a string of shots, without compounding the predictability with velocity migration.Ĭlearly the design of a successful new cartridge for ELR shooting would have to fall somewhat below the capacity of the overbore cartridges that produce problematic velocity migration. An error of only 8 fps represents a trajectory prediction error that exceeds the size of the target at 2 miles. Predicting what your MV will be with a high degree of accuracy is very important for ELR shooting.The pressure increase that comes with the velocity migration leads to problems like stuck cases and safety concerns with ammo that produced moderate/safe pressure only 50 shots ago.

This level of velocity migration causes two big problems for the serious ELR shooter. After 50 shots, the MV has migrated up 20 fps. With a velocity migration of 0.4 fps/shot, that means every 10 shots, your MV is increasing by 4 fps. shot count, the slope of that line indicates a velocity migration of between 0.9 fps/shot before the first cleaning, 0.7 fps/shot before the second cleaning, 0.4 fps/shot before the third cleaning, and 0.3 fps/shot before the fourth cleaning. The muzzle velocity of nearly every shot was measured for the first 3 cleanings of the barrel. Figure 2 shows an example of severe velocity migration that was measured for a 375 Lethal Magnum. Those with experience shooting large capacity wildcats are familiar with these problems, and the importance of restraining shot count, and frequent boreĬleaning to stave off the effects of overbore cartridges and velocity migration (velocity migration and pressure increase go hand-in-hand). We’ve come to refer to this problem as velocity migration. Chamber pressure and velocities can climb dramatically in just a few shots due to the extreme fouling conditions of such overbore cases. In other words, how overbore the cartridge is. The internal ballistic problems of large cartridges correlate to the case volume to bore diameter ratio. In this context, high maintenance means many things, and it’s important to understand the problems if a new cartridge is going to be designed to mitigate those problems. 375 caliber 400 grain bullet over 3200 fps, you generate incredible performance but it comes at the cost of high maintenance. When you burn over 150 grains of powder, and propel a. This cartridge showed promise when Mitch won the 2016 King Of 2 Miles ELR competition with it, but over time, the practical limitations of the case became apparent. Consider the 375 Lethal Magnum, a cartridge developed by Mitchell Fitzpatrick in 2016, based on the 585 Hubble Express. In the pursuit of ELR target engagement, high performance is always a goal, but some aspects of high performance can come at a cost. The concept of the EnABELR cartridge was born from experience with other large cartridges.

Saami 338 spectre