300 Blackout Vs 7.62×39 Reloading Data | How to Optimize 300 Blackout Ammo

As of right now the number one requested topic I get asked about is the availability of ammo when the prices are going to go back to “normal".

Many ammo companies are struggling because of the short supply of components, such as brass casings, primers, powder, and bullets. 

Instead of waiting on the companies to provide you with completed ammo for your guns, I highly recommend reloading your own ammo. Reloading .300 Blackout and 7.62x39mm ammo can save hundreds of dollars per range day if done correctly.

Choosing between the 300 AAC Blackout (300 BLK SAAMI specs) and the 7.62x39mm caliber bullets is simply a matter of preference. Do you prefer an AR-15 or are you an AK-47 kind of guy/girl?

300 Blackout vs 7.62x39 Juxtaposition
Steel Case is 122 Gr Tulammo 7.62×39, Brass is 125 Gr Fiocchi 300 BLK

A .300 AAC Blackout is specifically designed for use in an AR-15 (M4) platform, while a 7.62×39 bullet is meant for the most common AK platforms. I know many of our readers have many of both platforms and are looking for ways to shoot to proficiency and not go into debt in the process. 

Berry’s Superior Plated Rifle Bullets .300 AAC Blackout .308" 150 gr TMJSP 500/ct

at Natchez Shooting Supplies
Prices accurate at time of writing

.300 AAC Blackout

The 300 BLK was created by Remington Defense and the Advanced Armament Corporation (AAC). Before I started to shoot the 300 BLK I thought it was just a more advanced 5.56x45mm round made for close to mid-range shooting. However, the 300 BLK is much closer to the 7.62x39mm round in regards to ballistics. 

300 AAC Blackout Vs. 5.56×45?

The 300 BLK has the same overall length and width as the  5.56×45mm NATO and can be fired from any M4 or M16 (AR) platform with the same magazines and lower receiver. The only thing that needs to be changed is the barrel. The barrel of a  5.56×45mm NATO is smaller since the 300 BLK fires a .30 caliber bullet.

Why Was The 300 Blackout Created?

The 300 BLK was created as a potential solution to varying types of missions conducted by the men inside SOCOM. A 5.56x45mm is a very high-energy and incredibly fast bullet, reaching speeds up to 3,265 ft/s. Many soldiers were having problems with the stopping power of the 5.56x45mm NATO round and preferred the stopping power provided by a .30 Cal bullet instead. 

It’s no secret that the Ak-47 is the most popular war-fighting rifle in the world and it predominantly shoots a 7.62x39mm bullet. The goal of the 300 BLK was to find a way to fire a larger round inside the M4 platform. 


300 Blackout 5.56×45mm NATO
Overall Length2.26"2.26"
Case Length1.36"1.76"
Base Diameter0.376"0.377"
Bullet Diameter0.308"0.224"
Neck Diameter0.334"0.253"
Rifling Twist1:8" (203mm)1:7 (178mm) or 1:9" (229mm)
Primer TypeSmall RifleSmall Rifle
Max Pressure55,000 PSI (56,565 C.I.P.)62,366 PSI
Max Velocity2,486 ft/s (Hornady 115 Gr) Hodgdon Lil Gun Powder 3,260 ft/s (55 Gr FMJBT)

300 Blackout – 125Gr Elite Ball FMJ 20rd

at Kentucky Gun Company
Prices accurate at time of writing

Can I Shoot .300 AAC Blackout in a 5.56x45mm Chambered Barrel?

No, I don’t ever suggest mixing your ammo inside either a 300 BLK barrel or 5.56 NATO barrel. Since a 5.56 barrel shoots a .224" bullet while the .300 AAC Blackout shoots a .308" bullet, mixing the 2 will cause catastrophic failure and lead to serious injury or death. There are very few things in this world worth dying for and I promise this isn’t one of them. 

Can I Put a Suppressor on a 300 Blackout?

Absolutely, yes! In fact, one of the goals of a 300 BLK was compatibility with a suppressor attachment. This was due to the need for SOF soldiers to maintain noise discipline and remain covert in an urban assault. 

Most people I know with a 300 BLK use it specifically due to the compatibility of a suppressor and the cycling reliability that is expected with an AR. Furthermore, the compatibility of a subsonic round in conjunction with a suppressor offers an incredibly quiet shot from a .300 Blackout barrel.

We’ll get into the subsonic rounds in a future blog, but as far as the 300 BLK is concerned, just know that a subsonic bullet travels less than the speed of sound (1,100 ft/s). Subsonic bullets are normally really heavy at around 190-220 Gr and shoot around 1,050 ft/s. 

I look for 3 specs anytime I choose a suppressor (weight, length, and sound suppression). The Sig Sauer SLH .300 BLK Suppressor is specifically made to work with subsonic high-pressure bullets.

Subsonic bullets with the Sig Sauer SLH .300 BLK Suppressor is a perfect combination because the Sig suppressor vents off the gas from the explosion at a higher rate than most other brands (making it quieter) and does a phenomenal job at reducing flash. My favorite feature is how easy it is to mount with the audible and tactile click that you get from Sig’s Clutch Lok Direct thread design. 

Sig Sauer SLH Suppressor
Caliber.300 AAC Blackout
Weight0.88 lbs
MountClutch-Lok Direct thread

Sig Sauer SLH .300 BLK Titanium DT Rifle Suppressor

at Euro Optic
Prices accurate at time of writing

Hodgdon Reloading Data Center

Anytime I reload, I choose to always start with the Hodgdon Reloading Data Center for the most accurate information. I’ve been reloading for about 2 years now and as long as I’ve followed the guidelines from Hodgdon, my ammo has been safe and consistently accurate. Whichever bullet, powder, and primer you choose, each company will have load data available on its website. Starting with Hodgdon has saved me time and drastically improved my shooting accuracy, performance, and consistency.

Why Should I Reload 300 Blackout?

If you own a .300 Blackout rifle, then you know that the ammo is incredibly expensive and it doesn’t seem to be slowing down anytime soon. A decent box of 20 rounds online right now is at least $2.00 per round.

When you consider that you most likely have a 20-30 round magazine, you could shoot $100 in ammo in less than 2 minutes with a combat reload. Or you could reload your own .300 AAC Blackout at less than half the cost of factory ammo.

If you’re reloading 300 BLK subsonic bullets that are designed for use with a suppressor, reloading is the most consistent way to achieve optimal results for your specific gun. Being able to test each loadout and make small incremental changes to the level of powder and depth of the bullet can make big differences in your accuracy, consistency, and performance.

300 Blackout Reloading Data

There are many different powders you can choose for your 300 BLK ammo, so it depends on the purpose of your rifle and whether you’re running a silencer and/or subsonic bullets.

Some powders, such as the Hodgdon CFE BLK and the H4198 are more compatible with the heaviest of subsonic rounds (220 Gr) than the Trail Boss powder. Understanding the load data for each powder is as important as other detail in the reloading process.

H110 Load Data

H110 Max Load Data (Subsonic)GrainsVelocity (ft/s)Pressure (PSI)Bullet DiameterPrimerC.O.L.
190 Gr Hornady Sub-X9.6 Gr1,06722,400.308"Remington 7.5 Small Rifle Magnum2.055"
208 Gr Hornady A-Max9.2 Gr1,06022,700.308"Remington 7.5 Small Rifle Magnum2.055"
220 Gr Hornady SIE HPBT9.21,04628,100.308"Remington 7.5 Small Rifle Magnum2.235"

Lil Gun Load Data

Lil Gun Starting Load Data GrainsVelocity (ft/s)Pressure (PSI)Bullet DiameterPrimerC.O.L.
135 Gr Hornady SIE HP17.32,06942,000.308"Remington 7.5 Small Rifle Magnum2.055"
140 Gr Hornady NOS HPBT15.11,92236,000.308"Remington 7.5 Small Rifle Magnum2.055"
150 Gr Hornady IB14.61,85539,000.308"Remington 7.5 Small Rifle Magnum2.235"

H4198 Load Data

H4198 Max Load Data (Subsonic)GrainsVelocity (ft/s)Pressure (PSI)Bullet DiameterPrimerC.O.L.
190 Gr Hornady Sub-X11.51,05922,900.308"Remington 7.5 Small Rifle Magnum2.055"
208 Gr Hornady A-Max11.11,05219,900.308"Remington 7.5 Small Rifle Magnum2.260"
220 Gr Hornady SIE HPBT11.21,06921,800.308"Remington 7.5 Small Rifle Magnum2.260"

CFE BLK Load Data

Trail Starting Load DataGrainsVelocity (ft/s)Pressure (PSI)Bullet DiameterPrimerC.O.L.
135 Gr Hornady SIE HP20.71,89524,600.308"Remington 7.5 Small Rifle Magnum2.055"
140 Gr Hornady NOS HPBT18.51,77220,400.308"Remington 7.5 Small Rifle Magnum2.235"
150 Gr Hornady IB18.81,81026,600.308"Remington 7.5 Small Rifle Magnum2.230"


The 7.62x39mm bullet is one of the most popular cartridges in the world due to the Ak-47, RPK, and SKS rifles. The 7.62×39 is a bottleneck rimless case meant to be used at intermediate combat ranges (less than 500 yards). Obviously, the RPK can throw rounds much further, but not as accurate as a 7.62×63 bullet.

Unfortunately, the majority of all 7.62×39 cases are made of steel and feature a Berdan Primer. A Berdan Primer is the most common type of primer developed in Europe and features 2 flash holes for the ignition of the powder. As far as I know, you can’t reload Berdan primers without extensive gunsmithing and ammunition skills.

As you can see from the comparison below, the 7.62×39 has a longer and wider case, but a shorter overall length than the .300 Blackout. The biggest similarity is the velocity and pressure of the 2 bullets are almost identical. In fact, you could probably get them even closer by handloading your rounds.

The 300 BLK charged with the CFE BLK powder from Hodgdon is capable of identical bullet velocities, but with 15,000 PSI less in pressure. The 7.62×39 is a larger cartridge with less power than the 300 BLK, meaning a 300 BLK rifle can shoot with similar results with a shorter barrel and smaller frame.


300 Blackout7.62x39mm
Overall Length2.26"2.20"
Case Length1.36"1.52"
Base Diameter0.376"0.447"
Bullet Diameter0.308"0.309"
Neck Diameter0.334"0.339"
Rifling Twist1:8" (203mm)1:7 (178mm) or 1:9" (229mm)
Primer TypeSmall RifleBoxer Large Rifle (brass)
Berdan (steel case)
Max Pressure55,000 PSI (56,565 C.I.P.)45,010 PSI (51,490 C.I.P.)
Max Velocity2,486 ft/s (Hornady 115 Gr) Hodgdon Lil Gun Powder 2,421 ft/s (123 Gr FMJ)

7.62×39 Reloading Data

Due to the scarcity of boxer primer cases made for a 7.62×39 chamber, there are only a few options to reload the 7.62x39mm round.  A 300 BLK cartridge has many different powders and caseload options to dial in and get the most optimization out of your rifle. However, if you have a 7.62×39, chances are it’s an older gun that probably has some sentimental value and/or it’s really fun to shoot. Either way, reloading your own ammo will help you save money in the end.

IMR 4198 Starting Load DataGrainsVelocity (ft/s)Pressure (CUP)Bullet DiameterPrimerCaseC.O.L.
108 Gr BAR RRLP FB21.71,98537,5000.310"CCI 200 Large RifleMidway2.210"
125 Gr SPR SP22.62,03536,8000.311"CCI 200 Large RifleMidway2.150"
150 HSY SP21.21,91742,2000.311"CCI 200 Large RifleMidway2.220"

What Do I Need to Reload my Own 300 AAC Blackout Ammo?

Learning how to reload your own ammo can be very difficult or it can be challenging and rewarding. For me, it’s all about the tools you use because of the seriousness involved in creating mini explosives. Our readers have read enough articles about Frankford Arsenal by now that my level of trust for Frankford Arsenal products.

Since we’re talking about load data in this blog, there are several tools you’ll need in order to measure the powder, pour the powder into the case, seat the bullet, and install the primer. Owning these 13 tools gives you everything needed to start the reloading process. If you’re interested in learning the step-by-step process, read our Hands-On Beginner’s Guide to Reloading.

  1. Ammo Boxes/Reloading Trays
  2. Rotary Tumbler 7L
  3. Brass Cleaning Media
  4. Brass Cleaning Solution
  5. Single-Stage Reloading Press
  6. Intellidropper Electronic Powder Measurer
  7. Perfect Seat Hand Primer
  8. Calipers
  9. Aluminum Powder Funnels
  10. Universal Bullet Seating Die
  11. Hand Deprimer
  12. Case Trim & Prep Center
  13. Case Prep Expansion Tools

Do You Trust Your Powder Measure Tool?

This is the first and most important question to ask before reloading because if you don’t trust your tools, you can’t be at your best. You’re going to need a tool that can measure the weight of an individual grain to stay safe and ensure optimal performance.

There are many tools out there that you can use, but there is no better powder measure than the FA  Intellidropper. This one machine can measure and store all the different loads you enter into the machine for future use. Whichever bullet you choose to use, follow the guidelines from the Hodgdon Reloading Data Center and you’ll load like a pro in a short time.

Frankford Arsenal Intellidropper Powder Measure

at Amazon
Prices accurate at time of writing

How Do I Measure Gun Powder For My 300 BLK Using the FA Intellidropper?

One of the most nerve-racking feelings I got when I started to reload was how do I know for sure if the machine was giving me a good reading. Instead of regurgitating each step for you, I wrote a step-by-step guide on how to set up the Intellidropper to measure any load, including the 300 BLK and 7.62x39mm cartridges. A couple of things to keep in mind as you read our guide is that the environment where you place your Intellidropper matters. For example, if you’re trying to reload outside on a windy day, you’re never going to be able to dial in your optimal load.

Jarrod Grove (FA Brand Manager) showed me how wind from outside or a fan can throw your weight off and cause a bad reading. It’s also just as important to ensure that the Intellidropper is on a level surface so the scale is balanced.

Frankford Arsenal Powder Funnel Kit

The Aluminum Powder Funnel Kit is the unsung hero of powder distribution from the scale to the case. When I started, I was using a food-grade powder funnel that would only fit my rifle cartridges and oftentimes caused issues with stability. The Powder Funnel kit has a funnel for every caliber you could want to shoot from a .22LR through the .338 Lapua.

The best feature of the powder funnel is the magnetic base to allow for simple, easy, and stress-free powder charges. I can’t overstate the need for the FA Aluminum Powder Funnel Kit enough because it’s made my life so much easier and has prevented me from wasting time constantly pouring powder back due to spilled grains.

Frankford Arsenal Powder Funnel Kit

at Kentucky Gun Company
Prices accurate at time of writing

How Do I Seat My Bullet Using the Frankford M- Press?

The first thing you’ll want to do for a 300 BLK is to ensure you have the Universal Bullet Seating Die (10 on the list above) kit and choose the .308" bullet die. Using the FA digital calipers (8 on the list above), you can measure the bullet depth to the C.O.L. depth for your specific case and bullet. Watch the Ultimate Reloader show you how to seat your bullet using your load data and the tools I have listed in this blog.


Reloading doesn’t have to be difficult if you have the right tools, knowledge, space, and humility. I know humility seems like it’s not important, but from my experience, reloading will humble you at some point. Learning from the hard lessons of failure can only make you a better person and reloader. I’ve learned that buying universal reloading tools and supplies is the best option because it prevents me from accumulating too much gear. Fortunately, the FA Intellidropper, the Universal Bullet Seating Die Kit, the Universal tray holders, and the aluminum powder funnels work for my entire collection.

You might spend $300-$400 today on your tools, but if you shoot regularly, you’ll make up the cost with 3 or 4 trips to the range.  2 of my favorite things about reloading my own ammo is the self-dependence I now have and thousands of rounds that I can afford to shoot more than I did with factory ammo. It’s an awesome feeling to become a better shooter and save hundreds of dollars at the same time. I don’t know many hobbies that you can train more with and spend less money other than reloading your own ammo.

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Table of Contents

  • .300 AAC Blackout
  • 300 AAC Blackout Vs. 5.56×45?
  • Why Was The 300 Blackout Created?
  • Specs
  • Can I Shoot .300 AAC Blackout in a 5.56x45mm Chambered Barrel?
  • Can I Put a Suppressor on a 300 Blackout?
  • Hodgdon Reloading Data Center
  • Why Should I Reload 300 Blackout?
  • 300 Blackout Reloading Data
  • H110 Load Data
  • Lil Gun Load Data
  • H4198 Load Data
  • CFE BLK Load Data
  • 7.62x39mm
  • Specs
  • 7.62×39 Reloading Data
  • What Do I Need to Reload my Own 300 AAC Blackout Ammo?
  • Do You Trust Your Powder Measure Tool?
  • How Do I Measure Gun Powder For My 300 BLK Using the FA Intellidropper?
  • Frankford Arsenal Powder Funnel Kit
  • How Do I Seat My Bullet Using the Frankford M- Press?
  • Conclusion

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