• Home |
  • Hornady 300 Blackout 190 Gr Sub-X Review: Suppressor Ready

Hornady 300 Blackout 190 Gr Sub-X Review: Suppressor Ready

Hornady 300 Blackout 190 Gr Sub-X Review

If you’re looking for a high-quality subsonic round for your favorite 300 AAC Blackout rifle, then you can’t go wrong with the Hornady 190 grain Sub-X. This round is a perfect choice for deer hunting in the Midwest, blasting feral hogs down in Texas, and everything in between.

As this round is designed to produce excellent expansion at subsonic velocities, it’s the answer to every 300 Blackout hunter’s prayers. When paired with a suppressor this ammo is not only hearing safe, but darn near Hollywood quiet, making it ideal for fast follow-up shots and multiple target engagements out to 200 yards.

But if you’ve been wondering if the Hornady Subsonic juice is worth the squeeze, then you clicked on the right article. In this Hornady 300 Blackout 190 gr Sub-X review, I’ll share the details you need to know about this subsonic ammunition and why it’s a great choice for your suppressed or unsuppressed 300 Blackout bolt-action or AR-15 carbine.

If you’re ready to buy, we have Hornady 300 Blackout 190 Gr Sub-X ammo in stock and ready to ship to your door. Otherwise, keep reading for the full review.

Hornady 300 Blackout 190 Gr Sub-X Ammo Overview

Back in 1949 when Joyce Hornady founded his company, the needs of the American shooter were relatively simple. Most of them were returning from WWII and had experience using a 30-caliber bolt-action or semi-auto rifle.

It makes sense that Hornady’s first major success was a 30-cal 150 grain Spire Point hunting bullet. With so many surplus M1 Garands and 1903 Springfields hitting the market, this bullet mated perfectly with the 30-06 Springfield round, which was already popular for hunting.

However, as time forged on, the needs of the American shooter evolved with the advent of new cartridges and firearms. Sure, most 2A enthusiasts have a semi-automatic rifle like an AR-15 carbine or Ruger Mini-14 chambered in 5.56 NATO, but that same rifle can also be chambered in calibers like 300 Blackout, 6.5 Grendel, 6.8 SPC, or 450 Bushmaster.

Out of all these rifle calibers, the 300 AAC Blackout has been (by a wide margin) the most successful new cartridge adapted to the AR platform. The 300 Blackout (or 300 BLK for short) was developed to increase the stopping power of the AR-15.

Hornady 300 Blackout 190 Gr Sub-X Ammo

The 300 BLK is unique in that it can be fired at supersonic and subsonic muzzle velocities, giving shooters an incredible amount of versatility in terms of ammo selection. Developed to be fired with or without a suppressor, a 300 Blackout will experience a full powder burn in just 9 inches of barrel length, making it an ideal candidate for a SBR (short barrel rifle).

Although supersonic 300 Blackout ammo has proven to be extremely effective for hunting medium sized game like whitetail deer and hogs, subsonic ammo provided unreliable expansion at best. That is, until Hornady released the Sub-X bullet.

The Hornady 190 gr Sub-X bullet was designed to provide excellent expansion at low velocities.

To accomplish this, Hornady began with a soft lead core and encased it in a thin gilding metal jacket. Unlike tougher jacket metals used by traditional hunting bullets, gilding metal will deform and expand at lower pressures and is perfect for subsonic use.

To further increase expansion, Hornady topped their Sub-X bullets with the patented Flex Tip. This is the same polymer tip utilized in their LeveRevolution and Critical Duty lines of ammunition that has proven itself in the field for years.

Once the polymer tip encounters soft tissue, it plunges into the hollow point cavity to initiate rapid expansion of the jacket and lead core.

The result is that the Hornady Sub-X bullet has excellent weight retention, creates devastating wound channels, and can ethically harvest medium and small game animals with relative ease. So, if you’re looking for some subsonic ammunition for your favorite semi-automatic or bolt-action hunting rifle, then you really should give Hornady Subsonic 300 Blackout 190 grain Sub-X a look!

Our Hornady American 300 Blackout 190 Gr Sub-X Review

These no doubt that the 300 AAC Blackout is one of the most popular AR-15 rifle calibers across the USA, second only to the 223 Remington/5.56 NATO (yes, I know they’re different).

And one of the coolest aspects of the 300 Blackout is how it is designed to be fired at supersonic and subsonic velocities. This allows the round to be extremely versatile and fill multiple roles for shooters across the USA.

Hornady 300 Blackout 190 Gr Sub-X Ammo

With only a quick magazine change, a shooter can change between longer range supersonic ammo and close range, hard-hitting subsonic ammo.

Although the 300 AAC Blackout has never been formally accepted by the US Military, civilian shooters have flocked to the new round as it not only increases the stopping power of the AR platform, but it also has multiple hunting applications.

However, one thing that the hunting community has been pining over since its release was reliable 300 Blackout subsonic ammo. In the beginning, reloading was the only answer to creating subsonic hunting rounds with bullets like the 208 grain A-MAX or Lehigh 194 gr Maximum Expansion.

These bullets were great for smaller game animals, but what hunters wanted was a bullet that had enough penetration and expansion to take on larger game like whitetail or antelope.

The Hornady Sub-X bullet was the answer that these hunters were looking for and represents a culmination of multiple Hornady technologies into one lethal package.

What I love most about the Sub-X bullet design is how Hornady paid attention to what hunters were asking for and delivered a bullet that opens up reliably at subsonic velocities.

As with all Hornady ammo, Hornady Subsonic 300 Blackout is loaded in high-quality brass cases with Boxer primers that are perfect for reloading. And although I haven’t had a chance to run these rounds across a chronograph, I can tell the difference between how quiet they are compared to supersonic ammo when I shoot them unsuppressed in my 9” 300 BLK AR pistol.

Not only is Hornady 300 Blackout Subsonic ammo great for hunting, but it is also an exceptional self-defense round, meeting all the criteria laid forth in the FBI protocol for penetration and expansion. This makes it a great home defense round, as a subsonic 300 Blackout is hearing safe when coupled with a suppressor.

Although I’d value my life over my hearing any day, honestly, I’d like to have both! And thankfully with the Hornady Subsonic 300 Blackout 190 grain Sub-X, I can have my cake and eat it too!

Overall, I have nothing but good things to say about this Hornady ammo. It’s high-quality, extremely versatile, and a great option for hunting or home defense.

Hornady 300 Blackout 190 Gr Sub-X Ammo

For me, that’s the definition of exceptional ammo and I have no qualms about loading this into my home defense carbine every night before I turn out the lights.

And if you ask me, you can’t do much better than that!

What’s It Best For?

Hornady Subsonic 300 Blackout 190 grain Sub-X ammo is best for hunting medium to small game and for personal defense. As this ammo is designed to expand and extremely low velocities, it’s a great choice for home defense thanks to the low report of the round since it exits the barrel below the speed of sound.

Hornady also stipulates that their Subsonic ammo meets all terminal ballistic test requirements set forth in the FBI protocol, meaning that this ammo will get the job done when you need it most.


The only real downside to this ammo is the price, as it’s more expensive than Hornady Black or Hornady Frontier 300 BLK loads. This means Hornady Subsonic is not the best choice for plinking and since it is loaded to fire at subsonic velocities, its maximum effective range is shorter than supersonic ammo.

Pros and Cons

As much as we love ammo, we understand that no manufacturer is perfect. Here are some of the pros and cons of Hornady 300 Blackout 190 Gr Sub-X ammunition you should be aware of.


  • Designed to expand at low velocities
  • Hornady 300 Blackout 190 Gr Sub-X Ammo
  • Utilizes the patented Flex Tip technology to ensure proper expansion
  • Low report, hearing safe when fired with a suppressor
  • Great for hunting medium to small game
  • Accurate, most shooters report around 1 MOA


  • More expensive than other 300 Blackout loads from Hornady
  • Not ideal for plinking due to cost and limited range

Variation Review

Hornady 300 Blackout 190 Gr Sub-X comes loaded in one configuration. Below you’ll find our review to understand if this ammo fits your shooting needs.

Hornady 300 Blackout 190 Gr Sub-X Review

Hornady 300 Blackout 190 Gr Sub-X Cartridge Specifications

At the time of writing, there is only one Hornady Subsonic factory load, and it comes topped with the 190 grain Sub-X bullet. Made for exceptional expansion and velocities below the speed of sound, the Sub-X bullet is designed for hunting, home defense, and general subsonic shooting.

With an advertised muzzle velocity of 1,050 fps when fired from a 16-inch barrel length, this ammo is hearing safe when combined with a suppressor since there is no supersonic “crack”.

This ammo is perfect for deer hunters who don’t expect to engage whitetails or mule deer outside of 200 yards. It also is an excellent home defense round as it shouldn’t over penetrate and is designed to expand at subsonic velocities.

Ballistics for Hornady 300 Blackout 190 Gr Sub-X Ammo

Below we’ve compiled ballistics tables for the Hornady 300 Blackout 190 Gr Sub-X ammunition we reviewed in the previous section. Please note that muzzle velocities listed might vary depending on your barrel length.

Hornady 300 Blackout 190 Gr Sub-X Ballistics table

Note: This information comes from the manufacturer and is only informational. The actual ballistics obtained with your firearm can vary considerably from the advertised ballistics. Also, ballistics can vary from lot to lot with the same brand and type load.

Parting Shots

If you’re looking for 300 Blackout subsonic ammunition that will provide reliable expansion in the woods or during a home defense situation, you simply can’t go wrong with Hornady Subsonic 190 Gr Sub-X ammo.

Make sure to check out the Hornady 300 Blackout 190 Gr Sub-X ammo we have in stock and ready to ship to your door. And while you’re at it, make sure to check out all the other Hornady ammo we have to satisfy your itchy trigger finger. To further cut the costs of your future purchases, visit our 300 blackout bulk ammo page and get more ammo for a lower price.

Stay safe out there and we’ll see you on the range!


Below are some questions we get asked a lot here at Ammo.com about Hornady Subsonic 300 Blackout ammunition.

Hornady 300 Blackout 190 Gr Sub-X Ammo

Is Hornady 300 Blackout 190 grain Sub-X worth buying?

Yes, if you need a quality expanding 300 Blackout round for subsonic use, the Hornady 300 Blackout 190 grain Sub-X is a great choice. This round is appropriate for hunting and personal defense.

What is the range of Hornady 300 Blackout 190 grain Sub-X?

For deer hunting I wouldn’t take a shot further than around 150 yards with this ammo. However, for target practice you can push that out past 200 yards without excessive bullet drop.

What is the muzzle velocity of Hornady 300 Blackout 190 grain subsonic?

Hornady reports the muzzle velocity of their 190 grain subsonic ammunition at 1050 fps when fired from a 16” barrel. If your barrel length is shorter than 16-inches this then you should expect lower muzzle velocities.

Chris Dwulet
Written by
Chris Dwulet

Ammunition Reviews