300 HAMR vs 300 Blackout Ballistics & Uses – 2022 Comparison

The 300 Blackout proved to be an insanely enticing development when it hit the market a decade ago. The capability to quickly convert your AR-15 from a .22 caliber to a .30 caliber with just changing the barrel was amazing. However, there was still room for improvement, and that’s when Wilson Combat took interest and came with the 300 HAMR. A slightly different version of the 300 Blackout, which many people consider better. 

The concept is almost the same as the development of these rounds, but is one really better than the other? This comparison will find this out based upon facts which will be derived from real-life data. 

TL;DR: 300 HAMR vs 300 Blackout

Here’s a quick pros and cons comparison of these two cartridges for a brief overview.

300 HAMR

300 HAMR Rounds
Photo credit: sbrammunition.com

300 Blackout

300BLK rounds
Photo credit: fedarm.com


300 HAMR

Ammo is not very expensive

Capable of penetrating level IIIA armor

High powder capacity for better ballistics

Best terminal performance among all AR-15 rounds

Good mid-range trajectory and high stopping power

Compatible with AR-15 .223 Rem parts. Swaps only barrel and mags

300 Blackout

Rounds can fit a regular AR-15 mag

Great for use with SBR and suppressors

Offers supersonic and subsonic load options

Wide range of ammo choices with easy availability

Converts a .223 AR-15 into a .30 cal AR-15 with swap of a barrel

Achieves optimal performance in just nine inches of barrel length


300 HAMR

Doesn’t offer subsonic performance

Bullet weight is limited to 150 grains

Ammo is hard to find because the round is new

300 Blackout

Doesn’t shoot very flat

Short effective range for medium game, despite being a .30 cal

Best For

300 HAMR

The .300 HAMR can do everything that a .300 blk can, but better. It is great for hunting and defense

300 Blackout

Great for tactical uses, hunting small game, tactical uses and competition. Best for converting your AR-15 into a .30 cal

300 HAMR Overview

The .300 HAM’R, which is written as 300 HAMR, is an intermediate rifle cartridge developed by Wilson Combat and was introduced on the market in 2018. If you are familiar with the expanse of the AR-15 platform, you will be aware that Wilson Combat is a formidable player in that space, and also with unique and innovative developments in the industry. 

This round was designed to deliver the performance of a 7.62×39 or the venerable .30-30 Winchester in the AR platform without the change of most parts from the .223/5.56 caliber. The closest thing available for this until the introduction of this round was the .300 Blackout, but the .300 HAMR was designed to supersede it further in performance. 

Photo credit: ontargetmagazine.com

This round is very new on the market but very well-appreciated. It just got approved by SAAMI in 2020, when all of us were busy dodging the Covid-19 pandemic in lockdowns. This round offers effectiveness close to the .308 Winchester, which makes the AR-15 platform more powerful, without the need to switch over the AR-10 platform. 

The 300 HAMR has proven to be very effective in terms of accuracy, ballistics, and terminal performance, and has been found to surpass the popular 6.8 SPC and 6.5 Grendel in terms of killing power. Whether it is fact or fiction, we’ll be finding out in the upcoming sections. However, as of now, only Wilson Combat exclusively makes rifles and ammo for this cartridge. 

300 Blackout Overview

The 300 AAC Blackout, also known as the 300 blk, is an intermediate rifle cartridge developed by the Advanced Armament Corporation for use in the M4 carbine. The concept was to create a cartridge that fired a .30 caliber bullet, and could fit in an .223/5.56 M4 platform with the swap of just the barrel. 

The round was developed by AAC in collaboration with Remington, and was aimed for use by the special forces. The idea was to create a cartridge that was powerful enough and could be used in SBR’s or suppressed rifles. This was achieved with the .300 blk as this cartridge can achieve its full potential in just nine inches of barrel length. Plus, the heavy subsonic rounds are perfect for use with suppressors.

Photo credit: tactical-life.com

The 300 blk has been a favorite for AR-15 users, when they need to convert their .22 caliber AR-15 into a .30 caliber powerhouse. Although this round uses the .223 Rem as the parent case, the concept for its development was derived from the .300 Whisper which is almost the same thing. The round was approved by SAAMI in 2011, just a year after its development. 

Anyways, the 300 blk was thought to be a gamechanger for the military special forces, however, it never made it to the actual adoption past some test runs. As of now, only the Netherlands and the UK defense forces use it in very meager numbers, but it is insanely popular among the AR community, especially ranch owners. 

300 HAMR vs 300 Blackout: Cartridge Specs

Here’s a quick overview of the cartridge dimensions for these two rounds. 

300 HAMR300 Blackout
Bullet Diameter0.309 in (7.8 mm)0.308 in (7.8 mm)
Neck Diameter0.332 in (8.4 mm)0.334 in (8.5 mm)
Base Diameter0.378 in (9.6 mm)0.376 in (9.6 mm)
Case Length1.595 in (40.5 mm)1.368 in (34.7 mm)
Overall Length2.26 in (57 mm)2.26 in (57 mm)
Case Capacity26 grains21 grains
Max Pressure (SAAMI)57,500 psi55,000 psi
Typical Casing MaterialBrassBrass
Typical Bullet Weight (gr)110-150 grains110-150 grains

The 300 HAMR and 300 Blk are basically .223 Rem cases that have been trimmed down to accept a bigger and sometimes longer, .30 caliber bullet. This is the reason why these two cartridges use the same bolts and magazines as the .223 Rem rounds, and you just have to swap the barrel to convert your AR-15.

The 300 blk was always serving the purpose 300 HAMR replaced it for. However, this does not mean that both these cartridges are the exact same thing. As you can see in the table above, both these rounds are exactly the same in overall length and have the same base diameter, which is quite obvious for interchangeability with the .223 Rem AR-15 system. 

The 300 HAMR has a slightly longer case, which also allows it to hold almost 25% more powder than the .300 blk. This slight increase in powder is capable of giving the 300 HAMR an edge over the 300 blk, but we’ll elaborate on that in the upcoming sections. 

The 300 HAMR is loaded at a slightly higher chamber pressure than the 300 blk. However, both these rounds have a lot of options for bullets because they use .308 loads. One more thing to note here is that the 300 HAMR has bullet weights ranging from 95 to 150 grains, whereas, the 300 blk starts from 78 grains and goes all the way up to 220 grains. 

300 HAMR vs 300 Blackout: Ballistics

The ballistics data tells us about three major characteristics of a bullet – the trajectory, velocity, and kinetic energy. While the trajectory is helpful in determining how flat a bullet will travel, and how much sighting adjustments will be needed at a particular distance. Flat-shooting bullets are better for accuracy and require lesser adjustments. 

The velocity is a measure of the accuracy, and according to the general rule of thumb, a supersonic (faster than the speed of sound) bullet is more predictable and helps with accuracy. The kinetic energy helps decide the suitability of a bullet against different types of targets for optimal damage.

300 HAMR vs 300 Blackout: Trajectory

Check out this comparison of trajectories for these rounds out to a distance of 1,000 yards. The most common bullets have been used for evaluation for a general overview. 

300 HAMR

16.25” barrel/BC 0.215/110 grains
Lehigh Defense CC
16.25” barrel/BC 0.274 /135 grains
Hornady FTX
16.25” barrel/BC 0.417 /150 grains
Speer BTSP
100 yds: 0 “ Drop100 yds: 0 “ Drop100 yds: 0 “ Drop
200 yds: 6.1 “ Drop200 yds: 6.4 “ Drop200 yds: 6.4 “ Drop
300 yds: 22.9 “ Drop300 yds: 23.4 “ Drop300 yds: 22.2 “ Drop
400 yds: 55.4 “ Drop400 yds: 54.4 “ Drop400 yds: 49.4 “ Drop
500 yds: 110.3 “ Drop500 yds: 104.2 “ Drop500 yds: 90.4 “ Drop
1,000 yds: 967.9 “ Drop1,000 yds: 835.6 “ Drop1,000 yds: 621.7 “ Drop

300 blk

16” barrel/BC 0.290/110 grains
Hornady V-Max
9” barrel/BC 0.251/120 grains
Copper HP
16” barrel/BC 0.406/150 grains
FMJ Boat-Tail
100 yds: 0 “ Drop100 yds: 0 “ Drop100 yds: 0 “ Drop
200 yds: 6.5 “ Drop200 yds: 9.4 “ Drop200 yds: 10.3 “ Drop
300 yds: 23.4 “ Drop300 yds: 33.7 “ Drop300 yds: 34.7 “ Drop
400 yds: 54 “ Drop400 yds: 78.6 “ Drop400 yds: 76.9 “ Drop
500 yds: 102.7 “ Drop500 yds: 150.6 “ Drop500 yds: 140.2 “ Drop
1,000 yds: 806.3 “ Drop1,000 yds: 1075.6 “ Drop1,000 yds: 902.9 “ Drop

The data for trajectories of these rounds makes one thing very clear, that neither of these rounds is optimal for long range engagements as far as the trajectory is concerned. Making a side-by-side comparison, the 300 HAMR is definitely a better cartridge than 300 blk in terms of trajectory. 

Like I pointed out in the previous section, the extra charge volume definitely helps the 300 HAMR with a better terminal performance. For example, while a 300 HAMR drops an average of two feet at 300 yards, the 300 blk drops close to 2.5 feet at that range. 

Beyond a distance of 300 yards, both these cartridges begin to drop too much for taking a shot without adjustments on the sights. While the 300 HAMR has an average drop of about 100 inches at 500 yards, the 300 blk drops an average of 135 inches at that range. 

Photo credit: gundigest.com

Additionally, while neither of these rounds was designed for 1,000 yards (or even 500 yards for that matter), the .300 HAMR still has a flatter trajectory at that distance when compared with the 300 blk and 7.62×39 mm. So it definitely excels in trajectory and stays true to the expectations. 

300 HAMR vs 300 Blackout: Velocity & Kinetic Energy

After understanding the trajectory, let’s take a look at the velocity and kinetic energy data for these rounds. 

16.25” barrel/BC 0.215/110 grains
Lehigh Defense CC
16.25” barrel/BC 0.274 /135 grains
Hornady FTX
16.25” barrel/BC 0.417 /150 grains
Speer BTSP
100 yds: 2,160 ft/s, 1,140100 yds: 2,101 ft/s, 1,324 ft.lbs100 yds: 2,106 ft/s, 1,477 ft.lbs
200 yds: 1,807 ft/s, 798 ft.lbs200 yds: 1,826 ft/s, 1,000 ft.lbs200 yds: 1,922 ft/s, 1,231 ft.lbs
300 yds: 1,499 ft/s, 549 ft.lbs300 yds: 1,578 ft/s, 746 ft.lbs300 yds: 1,749 ft/s, 1,019 ft.lbs
400 yds: 1,248 ft/s, 380 ft.lbs400 yds: 1,361 ft/s, 555 ft.lbs400 yds: 1,588 ft/s, 840 ft.lbs
500 yds: 1,076 ft/s, 283 ft.lbs500 yds: 1,188 ft/s, 423 ft.lbs500 yds: 1,441 ft/s, 691 ft.lbs

300 blk

16” barrel/BC 0.290/110 grains
Hornady V-Max
9” barrel/BC 0.251/120 grains
Copper HP
16” barrel/BC 0.406/150 grains
FMJ Boat-Tail
100 yds: 2,094 ft/s, 1,071 ft.lbs100 yds: 1,799 ft/s, 863 ft.lbs100 yds: 1,724 ft/s, 990 ft.lbs
200 yds: 1,834 ft/s, 821 ft.lbs200 yds: 1,533 ft/s, 626 ft.lbs200 yds: 1,561 ft/s, 811 ft.lbs
300 yds: 1,597 ft/s, 623 ft.lbs300 yds: 1,307 ft/s, 455 ft.lbs300 yds: 1,411 ft/s, 663 ft.lbs
400 yds: 1,389 ft/s, 471 ft.lbs400 yds: 1,136 ft/s, 344 ft.lbs400 yds: 1,282 ft/s, 547 ft.lbs
500 yds: 1,218 ft/s, 362 ft.lbs500 yds: 1,024 ft/s, 279 ft.lbs500 yds: 1,174 ft/s, 459 ft.lbs

Both these rounds clock higher than 2,200 fps at the muzzle and share a significant supersonic range. However, the 300 HAMR is always a faster bullet than the 300 blk in comparable weights. While the 300 blk stays supersonic out to a distance of 500-600 yards, the 300 HAMR can stay supersonic out to 700 yards with the right loads. 

While these numbers for velocity are fascinating, when we couple them with the trajectory data, the effective range of these rounds quickly diminishes to under 400 yards. Now let’s add another factor to it for a more comprehensive overview – energy. 

Before we try to analyze the kinetic energy values, let’s first set a benchmark here. According to the general norms, and the hunting laws in most states, a minimum energy of 1,000 fpe is required to kill a deer, and a minimum energy of 1,500 fpe is suitable for big ungulates like elk and moose. 

Photo credit: rifleshooter.com

Data (and real-life experience) shows us that a 300 blk is not an effective deer or big game hunting round. Although some hunters would say otherwise, and with proof on their trophy board or inside their freezer. It is not suitable to hunt a deer with 300 blk, not unless it is within the 100 yard range. 

On the other hand, the 300 HAMR can punch with 1,500 within 100 yards with the 150 grain loads, and has the capability of taking down deer out to 300 yards with the heavy 150 grain loads. As far as reality is concerned, I have come across hunters who have used the 300 HAMR to harvest deer at 220 yards. 

Comparatively, the 300 HAMR is definitely a 300 blk on steroids, and has better velocity and a higher energy. 

300 HAMR vs 300 Blackout: Stopping Power

The stopping power is the measure of a bullet to effectively obliterate/stop a target as quickly as possible. While the notion says that a bigger bullet will always have more stopping power, it is not always true. Even smaller bullets can have better stopping power than big caliber rounds, and the two most effective metrics to evaluate are the momentum and sectional density of a bullet. 

300 HAMR vs 300 Blackout: Momentum & Sectional Density

A collection of the data regarding the momentum and sectional density value for 300 HAMR and 300 blk bullets.

300 HAMR

16.25” barrel/BC 0.215/110 grains
Lehigh Defense CC
Sectional Density: 0.165
16.25” barrel/BC 0.274 /135 grains
Hornady FTX
Sectional Density: 0.203
16.25” barrel/BC 0.417 /150 grains
Speer BTSP
Sectional Density: 0.224
100 yds: 33 lb.ft-s100 yds: 40 lb.ft-s100 yds: 45 lb.ft-s
200 yds: 28 lb.ft-s200 yds: 35 lb.ft-s200 yds: 41 lb.ft-s
300 yds: 23 lb.ft-s300 yds: 30 lb.ft-s300 yds: 37 lb.ft-s
400 yds: 19 lb.ft-s400 yds: 26 lb.ft-s400 yds: 34 lb.ft-s
500 yds: 16 lb.ft-s500 yds: 22 lb.ft-s500 yds: 30 lb.ft-s

300 blk

16” barrel/BC 0.290/110 grains
Hornady V-Max
Sectional Density: 0.166
9” barrel/BC 0.251/120 grains
Copper HP
Sectional Density: 0.181
16” barrel/BC 0.406/150 grains
FMJ Boat-Tail
Sectional Density: 0.226
100 yds: 32 lb.ft-s100 yds: 30 lb.ft-s100 yds: 36 lb.ft-s
200 yds: 28 lb.ft-s200 yds: 26 lb.ft-s200 yds: 33 lb.ft-s
300 yds: 25 lb.ft-s300 yds: 22 lb.ft-s300 yds: 30 lb.ft-s
400 yds: 21 lb.ft-s400 yds: 19 lb.ft-s400 yds: 27 lb.ft-s
500 yds: 19 lb.ft-s500 yds: 17 lb.ft-s500 yds:  25 lb.ft-s

The sectional density of an object is the ratio of its mass to its cross-sectional area. The higher the value of SD, the more penetration will be caused by the object, which is because the force of a larger moving mass will be concentrated on a small area. An SD of less than 0.220 is suitable for hunting small game, an SD of 0.230 to 0.260 is good for medium sized game (like deer), and an SD of 0.270 and above is good for all big game animals. 

The 300 HAMR and 300 blk essentially use .308 inch diameter bullets, so the ballistics coefficient and sectional density values are the same. However, the light and medium weight bullets are mostly suitable for varmints, whereas the heavy bullets are good for medium sized game. Neither of these rounds is suitable for big game animals, however, they carry enough power to penetrate obstacles. Both these rounds can penetrate level IIIA armor. 

Another important measure of stopping power is the momentum of a bullet. It defines the intensity of energy transfer from a moving object to the other object upon collision. So the higher the value of momentum, the more damage will be done by the bullet. In other words, a higher momentum means a larger wound channel. 

Since momentum is the product of mass and velocity, and both these rounds have the same mass and sectional density, it is the velocity which acts as the decisive factor. The 300 HAMR moves at a faster velocity and carries about 30% more momentum than the 300 blk in comparable bullet weights. 

Photo credit: all4shooters.com

300 HAMR vs 300 Blackout: Use Cases & Effective Range

The data for ballistics and stopping power for these rounds gives us a brief overview of the accuracy, effective range, and the obliterating power of these rounds. However, let us now understand the best use cases for these rounds in detail. 

Small Game Hunting

The 300 HAMR and 300 Blk are suitable for varminting, but I’d rather not project them as suitable for all small games. These are .30 caliber rounds, and while taking down a coyote or prairie dog may seem viable, I think that .22 caliber rounds, like the common .223 Rem are still a better option for small game. 

As far as varminting is concerned, I think both these rounds work great against hogs. Additionally, hogs come in different sizes and roam in groups which can number in hundreds. So these rounds are good against all hogs, big or small. 

Medium Game Hunting

The kinetic energy and sectional density data have already told us that only the heavy bullets (150 grains) of these rounds are suitable for medium size game like deer. However, if you look closely at the data, you will find that the 300 HAMR has a longer range and higher power than the 300 blk, making it a better choice for medium game hunting. However, make sure to keep the range within 200 yards for the 300 HAMR, and less than 100 yards for the 300 blk

Big Game Hunting

Although they use a .308 inch diameter bullet, both these rounds do not qualify as a viable big game hunting round because of their unsuitable energy and range. These are a ton of better rounds for hunting big game animals, and on top of that, these rounds were not designed for hunting big game, so they are not to be blamed. 


The 300 blk had already left its print on the competition arena when SSG Daniel Horner of the USMAU used it to bag his fourth USPSA multi-gun national championship. The 300 HAMR, although better in performance, is the new kid on the block, and I have yet to encounter someone using it for a competition. For example, the Sierra SPT PHC 125 gr 300 HAMR is a great overall choice if you want to try your hands on this new cartridge. 

The 300 HAMR is very accurate because the twist rate pertains to a set bullet length and velocity. However, the 300 blk was designed for both supersonic and subsonic ammo, making the twist rate a bit vague. 

Photo credit: firearmsnews.com

Tactical and Defense Operations

The .300 blk was designed to be used as a tactical round for special forces working with SBRs. It is an amazing cartridge for use with heavy subsonic loads (up to 220 grains), and it can deliver its full potential in a short nine-inch barrel. 

The 300 HAMR is a faster and more powerful round, but it is more inclined towards supersonic performance and only allows bullets as heavy as 150 grains. Additionally, both these rounds are capable of penetrating body armor, which makes them even more suitable for such uses. 

Home or Ranch Defense

I’d say that both these rounds are quite overpowered for home defense applications. Since these .30 caliber rounds can easily penetrate obstacles, you are very likely to put innocent lives into jeopardy. However, if you were living on a ranch with lots of open space and almost negligent possibilities of bystanders, these rounds are great to tackle two as well as four legged hostiles. Additionally, these are also a great option for survival and self-defense rounds when you are out in the woods. 

300 HAMR vs 300 Blackout: Costs, Availability, & Compatibility

Now check out the realistics related to the costs, available options, and the real in’s and out’s of owning these rounds.

Costly and Available vs Rare

The 300 blk has been on the market for slightly more than a decade and being an AR-15 easy replacement cartridge, it has picked up a lot of popularity. To the extent that the ammo is readily available and can be found at almost all gun stores. The ammo costs anywhere between $1.3 to $4 per round and is almost twice as costly as the .223 Rem ammo.

The 300 HAMR has been around for just four years and got approved by SAAMI recently. As of now, only Wilson Combat and one other company manufacture ammo, and it costs between $1.5 to $1.8 per round. The 300 HAMR costs less than the 300 blk, however, you can only find the ammo though Wilson Combat on their online store.

Extensive Customizability 

Both these rounds were designed to easily convert an AR-15 into a .30 caliber rifle. Wilson Combat has come up with a magazine that can hold 300 blk, 300 HAMR, and .223 Rem rounds so you don’t have to carry different mags. Being made for the AR-15 platform, the possibilities for customization and aftermarket upgrades are almost endless. 

Bottom Line

The 300 blk was designed for tactical uses by special forces as a hard-hitting round that could quickly replace the 5.56/.223 with the swap of a barrel and magazine. This round can achieve terminal performance with just nine inches or barrel length and can work with both supersonic and subsonic ammo. In fact, it is one of the best rounds for use with SBR and suppressors. 

The 300 HAMR is an enhanced version of the 300 blk, designed to achieve the ballistics performance of the .30-30 Winchester. It is a slightly bigger and high-powered version of the 300 blk with better ballistics (trajectory, velocity, and energy) and more stopping power. It is an amazing round for hunting medium game and the potential to down big game within an appropriate range. 


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