Reloading the 300 Blackout Subsonic: A Guide

The 300 Blackout cartridge has gained immense popularity in recent years, and with good reason. Its unique design allows for subsonic loads to be used effectively, making it an excellent choice for suppressor owners. In this article, we'll explore reloading the 300 Blackout subsonic round using various powders and projectiles.

Initial Experimentation

I initially experimented with reloading the 300 Blackout using cast bullets and 90-grain XTP pistol bullets. The results were impressive, with a 5-shot group at 75 yards measuring only 2.070 inches. To achieve this accuracy, I used Federal Premium AR Match Small Rifle Primers and new Lapua brass.

Powder Selection

When it comes to selecting a powder for reloading the 300 Blackout subsonic round, there are many options available. One of my personal favorites is Trail Boss, which is known for its fast burn rate and ability to produce high velocities. However, it's essential to note that Trail Boss can be quite bulky, and compressing it may not be possible in a 300 Blackout case without causing excessive pressure.

Load Development

To develop loads for my 300 Blackout pistol, I used a ProChrono DLX Chronograph to measure the speed of each round. This device connects via Bluetooth to your phone, allowing you to track shot strings and analyze your results. With this data, I was able to fine-tune my loads and achieve impressive accuracy.

Load Recipes

Over the years, I've developed several load recipes for my 300 Blackout pistol. One of my favorite combinations is a 10.0-grain Trail Boss load with a 90-grain XTP bullet, which produces a velocity of around 1,000 fps. Another option is a 13.4-grain Lil Gun load with a 180-grain bullet, which yields a speed of approximately 1,680 fps.

Reloading the 300 Blackout subsonic round can be an enjoyable and rewarding experience. By experimenting with different powders and projectiles, you can develop loads that meet your specific needs and preferences. Remember to always follow safety guidelines and consult reliable load data when developing new recipes. With patience and practice, you too can achieve impressive accuracy and enjoy the many benefits of reloading your own ammunition.

Important Safety Note

Before attempting to reload any cartridge, it's essential to ensure that you're using the correct powder charges and not exceeding maximum pressures. Reducing powder charges can lead to dangerous pressures, so always consult reliable load data before making any changes.

Reloading 300 blackout subsonic