The .338 ARC and .450 Bushmaster can both be chambered in AR-15-platform firearms, but they were developed around very different ideas. The .338 ARC emphasizes efficient use of heavy .338-caliber projectiles, compact-barrel performance, and both supersonic and subsonic applications. The .450 Bushmaster uses a much larger-diameter .452-inch projectile and has established itself primarily as a powerful straight-wall hunting cartridge.
For hunters choosing between them, .450 Bushmaster has the advantage of established straight-wall hunting use and substantial close-to-moderate-range energy, while .338 ARC offers a more modern, versatile approach with smaller-diameter, aerodynamically efficient projectiles and strong compatibility with compact and suppressed AR configurations.
Neither is universally better. The better cartridge depends on what you expect your AR-15 to accomplish.
.338 ARC vs. .450 Bushmaster at a Glance
| Feature | .338 ARC | .450 Bushmaster |
|---|---|---|
| Platform | AR-15 | AR-15 |
| Bullet Diameter | .338" | .452" |
| Cartridge Type | Bottleneck | Straight-wall |
| Primary Strength | Versatility & heavy-projectile efficiency | Big-bore hunting |
| Supersonic Loads | Yes | Yes |
| Subsonic Loads | Yes | Less central to cartridge's role |
| Compact Barrels | Strong application | Possible, configuration dependent |
| Suppressor-Oriented Use | Major design/application advantage | Possible with appropriate equipment |
| Straight-Wall Hunting | No | Yes |
| Typical Role | Hunting, compact & suppressed ARs | Hunting / big-bore AR |
The distinction between bottleneck and straight-wall is particularly important for hunters because some jurisdictions have cartridge-specific hunting requirements.
Always verify current state and local hunting regulations before choosing a firearm or ammunition for hunting.
What Is .338 ARC?
Hornady's .338 ARC (Advanced Rifle Cartridge) is a relatively new cartridge designed around the dimensional limitations of the AR-15.
It uses .338-inch projectiles and was developed to provide heavy-bullet performance from the smaller AR-15 platform without requiring the larger AR-10 receiver set.
One of the defining characteristics of the cartridge is its ability to accommodate both supersonic and heavy subsonic ammunition, giving it a broader range of potential configurations.
That has made .338 ARC particularly interesting for:
- Compact AR platforms
- Hunting
- Suppressor-oriented configurations
- Heavy-projectile applications
- Shooters wanting something substantially different from traditional 5.56 AR performance
The cartridge also uses a bolt face associated with the 6.5 Grendel family, meaning a .338 ARC conversion requires the appropriate barrel, bolt and magazine rather than simply replacing the barrel on a 5.56 AR.
Related Guide: The Ultimate Guide to .338 ARC
What Is .450 Bushmaster?
The .450 Bushmaster takes a very different approach.
Rather than using a relatively aerodynamic smaller-diameter projectile, .450 Bushmaster launches a much larger .452-inch bullet from an AR-15-compatible cartridge.
Its straight-wall case has helped make the cartridge particularly popular among hunters, including in jurisdictions where certain straight-wall cartridges are permitted for deer hunting.
The cartridge is commonly associated with:
- Deer hunting
- Hog hunting
- Woods hunting
- Short-to-moderate-range applications
- Big-bore AR-15 rifles
Where .338 ARC represents a newer generation of cartridge design, .450 Bushmaster is already an established member of the big-bore AR-15 family.
Ballistics: Two Completely Different Approaches
Looking only at caliber diameter can be misleading.
These cartridges achieve their performance in fundamentally different ways.
.338 ARC
The .338 ARC uses a smaller-diameter projectile with the potential for comparatively streamlined bullet profiles.
Its design emphasizes efficient use of heavier bullets within the AR-15's dimensional limitations.
Depending on ammunition, it can be configured around either supersonic or subsonic performance.
.450 Bushmaster
The .450 Bushmaster launches a substantially larger-diameter projectile.
Its appeal isn't centered around long, aerodynamically efficient bullets. Instead, it provides substantial projectile diameter and energy for hunting at the distances where the cartridge is commonly used.
That makes the comparison less about:
"Which caliber is more powerful?"
and more about:
"What type of performance do I actually need?"
.338 ARC vs. .450 Bushmaster for Deer Hunting
This is likely to be one of the most important search questions surrounding these two cartridges.
Both can have hunting applications, but .450 Bushmaster has a major advantage for hunters specifically seeking a straight-wall cartridge.
The cartridge became particularly popular in areas where hunting regulations historically restricted hunters to shotguns or later permitted qualifying straight-wall rifle cartridges.
For wooded environments and moderate hunting distances, .450 Bushmaster has developed a strong reputation as a deer cartridge.
The .338 ARC approaches hunting differently. Its smaller-diameter, modern projectile selection can make it attractive to hunters wanting an AR-15 that isn't dedicated solely to traditional straight-wall hunting.
Choose .450 Bushmaster when:
- Straight-wall compliance is important
- Deer/hog hunting is the primary application
- Large projectile diameter is desirable
- Most shooting will occur at relatively moderate distances
Consider .338 ARC when:
- You want greater configuration versatility
- Compact barrel performance matters
- Suppressor use is an important consideration
- You want both supersonic and subsonic ammunition options
- Your hunting regulations don't require a straight-wall cartridge
Recoil Comparison
The .450 Bushmaster's combination of a relatively heavy projectile and substantial muzzle energy generally produces more noticeable recoil than typical intermediate AR-15 cartridges.
Rifle weight, stock configuration, buffer system, ammunition and muzzle device can all significantly affect perceived recoil.
The .338 ARC's recoil characteristics likewise vary by ammunition, particularly because supersonic and subsonic loads can behave quite differently.
For recoil-sensitive shooters, comparing the actual firearms and ammunition is more meaningful than comparing caliber names alone.
Barrel Length
This is an area where .338 ARC becomes particularly interesting.
.338 ARC Barrel Length
The cartridge has generated considerable interest for compact configurations.
Depending on the application, .338 ARC barrels can range from very compact pistol configurations through conventional rifle lengths.
Moriarti's .338 ARC lineup particularly emphasizes compact platforms, including short-barreled configurations.
.450 Bushmaster Barrel Length
The .450 Bushmaster is commonly encountered in traditional hunting-rifle configurations, with 16-inch barrels being especially practical for AR-15 hunting rifles.
Longer barrels are also available for hunters prioritizing different handling and velocity characteristics.
For a woods rifle, a 16-inch .450 Bushmaster can provide a relatively compact package while retaining the characteristics that made the cartridge popular with hunters.
Suppressor Use
This is another area where the two cartridges diverge.
The .338 ARC was developed during an era when suppressed shooting and heavy subsonic ammunition were already important considerations in cartridge development.
That makes suppressed .338 ARC one of the cartridge's most interesting applications.
The .450 Bushmaster can also be suppressed when using a suppressor specifically rated for the cartridge, appropriate barrel length, muzzle threads and ammunition.
However, the required bore diameter means suppressor selection differs substantially from .338 ARC.
Always follow the suppressor manufacturer's caliber, pressure, barrel-length and ammunition ratings.
Ammunition Availability
Here the older cartridge currently has an inherent advantage.
The .450 Bushmaster has been commercially available for many years, resulting in a more mature ecosystem of hunting ammunition, barrels and components.
The .338 ARC is considerably newer.
Factory ammunition and component availability have expanded since introduction, but buyers should consider ammunition availability before committing to any newer cartridge.
This balance may change considerably as .338 ARC adoption increases.
AR-15 Compatibility
Both cartridges can operate within the AR-15 platform, but neither should be treated as a simple 5.56 barrel swap.
A .338 ARC configuration requires appropriate:
- Barrel
- Bolt
- Magazine
- Muzzle device
- Properly matched operating components
A .450 Bushmaster configuration likewise requires appropriate:
- Barrel
- Bolt
- Magazine
- Muzzle device
- Properly matched operating components
The familiar AR-15 receiver architecture remains, but caliber-specific components are essential.
Which Has Better Range?
For this comparison, "range" needs context.
A cartridge's useful range isn't determined solely by muzzle energy. Projectile shape, ballistic coefficient, velocity, ammunition selection, target and shooter ability all matter.
The .338 ARC's modern projectile options can provide advantages when retaining velocity and trajectory become priorities.
The .450 Bushmaster is generally better understood as a large-diameter hunting cartridge optimized around the distances at which many deer and hog hunters actually take game, rather than as a long-range precision cartridge.
That distinction is more useful than assigning either cartridge an arbitrary maximum range.
.338 ARC vs. .450 Bushmaster for Hunting
For the hunter standing in front of both options, simplify the decision:
Choose .338 ARC if you prioritize:
Versatility.
It makes sense for someone interested in a modern AR cartridge that can transition between compact, hunting, supersonic and suppressor-oriented configurations.
Choose .450 Bushmaster if you prioritize:
Straight-wall big-bore hunting.
It remains an excellent option for hunters wanting a well-established large-diameter AR-15 cartridge, particularly where qualifying straight-wall cartridges have regulatory advantages.
Where .350 Legend and .400 Legend Fit
There's another important consideration.
If you're researching .450 Bushmaster because you want a straight-wall AR hunting cartridge, it shouldn't be evaluated in isolation.
Other important options include:
- .350 Legend
- .400 Legend
- .450 Bushmaster
These cartridges occupy different points on the straight-wall spectrum and deserve their own comparison.
Related Guide: .350 Legend vs. .400 Legend vs. .450 Bushmaster (recommended future article)
That article would also directly support your .400 Legend Upper category.
Which Cartridge Should You Choose?
There isn't a universal winner in the .338 ARC vs. .450 Bushmaster comparison.
They're simply too different.
For hunters operating under straight-wall cartridge rules or wanting an established big-bore AR hunting cartridge, .450 Bushmaster is the more obvious choice.
For shooters looking for a newer cartridge with heavy-projectile capability, compact-barrel potential, and strong suppressed/subsonic versatility, .338 ARC deserves serious consideration.
The deciding factors should be:
- Local hunting regulations
- Intended game
- Typical shooting distance
- Desired barrel length
- Recoil preference
- Suppressor plans
- Ammunition availability
- Whether straight-wall eligibility matters
Once those questions are answered, the choice becomes much easier.
Frequently Asked Questions
Is .338 ARC more powerful than .450 Bushmaster?
"More powerful" isn't a particularly useful comparison because the cartridges are designed for different purposes. The .450 Bushmaster launches a substantially larger-diameter projectile and is established as a big-bore hunting cartridge, while .338 ARC emphasizes efficient heavy-bullet performance and broader configuration versatility within the AR-15.
Is .338 ARC a straight-wall cartridge?
No. .338 ARC is a bottleneck cartridge. Hunters subject to straight-wall cartridge requirements should verify whether it is permitted before hunting with it.
Is .450 Bushmaster a straight-wall cartridge?
Yes. The .450 Bushmaster is a straight-wall cartridge, which has contributed significantly to its popularity among hunters in jurisdictions permitting qualifying straight-wall rifle cartridges.
Which is better for deer hunting: .338 ARC or .450 Bushmaster?
Both may be suitable depending on ammunition and applicable hunting laws. .450 Bushmaster has an advantage where qualifying straight-wall cartridges are required or preferred, while .338 ARC provides a different combination of projectile design, compact-platform potential and versatility.
Which has more recoil?
A typical .450 Bushmaster hunting load can produce substantial recoil from a lightweight AR-15. Actual perceived recoil for either cartridge depends on ammunition, firearm weight, buffer configuration and muzzle device.
Can you suppress .338 ARC?
Yes, with an appropriately rated suppressor and compatible firearm configuration. Heavy subsonic ammunition is an important part of the .338 ARC ecosystem.
Can you suppress .450 Bushmaster?
Yes, provided the suppressor is specifically rated for .450 Bushmaster and the firearm meets the suppressor manufacturer's requirements.
Do .338 ARC and .450 Bushmaster use a standard 5.56 bolt?
No. Both require appropriate caliber-specific components rather than a standard 5.56 bolt setup.
Final Verdict: .338 ARC vs. .450 Bushmaster
The .338 ARC and .450 Bushmaster demonstrate just how versatile the AR-15 platform has become.
The .450 Bushmaster remains a compelling choice for hunters who want a proven, large-diameter straight-wall cartridge. The .338 ARC represents a newer approach, combining heavy .338-caliber projectiles with compact-platform and suppressor-oriented versatility.
Rather than asking which cartridge is universally better, ask which one better matches your intended application.
For straight-wall hunting, start with the .450 Bushmaster.
For modern heavy-projectile versatility in the AR-15, take a close look at the .338 ARC.
