The 338 ARC is exciting the firearms community, offering a blend of ballistic performance, subsonic capability, and platform compatibility that appeals to hunters, casual shooters, and tactical enthusiasts alike. Whether you're looking to enhance your range time or improve your hunting game, the 338 ARC delivers. We'll dive into what makes this cartridge stand out, how it compares to others like the 8.6 BLK and 300 BLK, and why it's the perfect fit for both AR-15 and bolt-action platforms.
If you're searching for a versatile round with serious stopping power, the 338 ARC might just be your new go-to.
Table of Contents:
What is 338 ARC?
The 338 ARC (Advanced Rifle Cartridge) is the latest powerhouse developed by Hornady, specifically designed for AR-15 and bolt action platforms. The 338 ARC joins the ARC family as the big bore, subsonic focused option, joining the supersonic 6ARC and 22ARC cartridges. It brings exceptional terminal performance in both supersonic and subsonic variants, making it a versatile choice for everything from target shooting to hunting.
The 338 ARC features subsonic and supersonic loads for maximum versatility, but the Hornady engineers tailored the round towards the subsonic performance. The 338 ARC uses a small case capacity to make subsonic ammo more consistent and they developed a special SUB-X bullet specifically for the round. The new Subsonic ammo will combine a heavy expanding bullet with modern ballistic engineering, the 338 ARC fits within a compact package, providing a hard-hitting punch and superb accuracy without the bulk.
Why 338 ARC?
The 338 ARC stands out for featuring large bore performance in a small frame AR platform. It’s designed to deliver reliable cycling across a range of firearms and excels in both subsonic and supersonic applications. Whether you're using it for recreational shooting, tactical applications, or hunting, a 338 ARC rifle will offer excellent downrange energy and precision, all while fitting in a compact AR-15 platform. Its energy retention is impressive, making it a game-changer for those seeking superior ballistics without sacrificing portability.
338 ARC vs. 8.6 BLK
Both the 338 ARC and 8.6 BLK are gaining popularity in the world of firearms, but they serve slightly different purposes.
Both rounds use a .338 diameter bullet, and both offer subsonic and supersonic capabilities, but that’s where the similarities end.
The 8.6BLK is designed to be fired from large frame AR10 or short action bolt guns. It was designed to be the AR10 successor to the 300BLK, and it accomplishes that goal very well. The 8.6 uses a wide range of bullets, from 160 grain supers to 350 grain subsonic. The larger case capacity of the 8.6 means that it can achiever higher velocities than the 338 ARC when shooting supersonics.
.338 ARC on the other hand is tailored towards subsonic performance, and uses bullets ranging from 175 grain supers to 307 grain subsonics in the current Hornady ammo offerings. The 338 ARC is designed to work in AR15’s meaning shooters can enjoy a smaller. Lighter, and more compact package. And the reduced case capacity of the 338 ARC will lend itself to more consistent and more accurate subsonic loads.
338 ARC vs. 300 BLK
While these two rounds do not share the same projectiles they do share the same platforms. So, which AR15 round should you go with?
The 300 Blackout (300 BLK) has long been a popular choice for AR-15 users looking for versatility in both supersonic and subsonic rounds. However, the 338 ARC offers a more powerful alternative. While both rounds perform well at short to mid-range, the 338 ARC provides greater energy retention and better terminal ballistics at longer distances.
The 338 ARC excels where the 300 BLK starts to fall short. Its larger, heavier bullets (up to 307 grains in subsonic form) generate more impact, making it a better option for hunting or tactical use where maximum stopping power is necessary.
The 300 BLK is still a fantastic choice for close-range engagements and use in SBRs, and with the plethora of reloading components and ammo currently available, 300BLK will likely be significantly less expensive than the 338 for some time.
338 ARC Subsonic
One of the most exciting features for me of the 338 ARC is its subsonic performance. With a heavy 307-grain SUB-X bullet, it offers about 1.5 times the energy of the popular 300 Blackout subsonic round. This makes it a fantastic option for quiet, precision shooting, where sound suppression is critical without compromising terminal effectiveness.
The biggest advantage that the .338 ARC has is its case size. Traditionally, subsonic loads have very bad consistency and muzzle velocity standard deviation (SD). This is due to the case size. Subsonic loads use very small powder charges, and in some cases may only fill 25% of the case, all of that extra air and unused volume create inconsistent ignition and powder burn, which translates to diminished accuracy down range.
The 338 ARC uses a case designed for subsonic loads, it is smaller and uses a shoulder angle optimized for subsonic powders. This results in more consistent velocities and SDs, and will translate to smaller groups down range. The 338ARC is also higher pressure than 300BLK, which can lead to more consistent powder burn. This added pressure also means there is a smaller difference between the sub and supersonic pressures, meaning your AR15 will run more reliably even when switching ammo types.
Hunting with 338 ARC
For hunters, the 338 ARC offers a new level of versatility. Its terminal ballistics and projectile options make it perfect for taking down medium to large game, with both subsonic and supersonic options available to match your needs.
The cartridge’s adaptability means it can be used in a variety of environments—from dense woods to open fields—giving hunters a reliable tool for every situation. Its AR-15 compatibility also means hunters can enjoy lighter platforms without sacrificing ballistic performance. .338 ARC will also be ideal in short barreled rifles (SBRs) so hunters can use very light and compact weapon systems that are accurate and easy to shoot.
Hornady engineers said that subsonic hunting was at the forefront of 338 ARC development and have reportedly done a lot of testing on hunts with the cartridge. They state that the effective range of 338 ARC subsonic is about 200 yards on deer, hog, or similar animals.
Suppressors for 338 ARC
If you're shooting the 338 ARC, especially in subsonic form, using a suppressor will take it to the next level. The 338 ARC is set to perform remarkably well with suppressors, reducing not only the sound signature but also the felt recoil, making follow-up shots quicker and easier.
A quality suppressor will not only protect your hearing but also allow you to remain undetected in hunting or tactical situations. The subsonic performance of the 338 ARC paired with a suppressor creates an ultra-quiet shooting platform that’s both stealthy and effective.
The 338 ARC will work in most suppressors .338 and larger, generally if a suppressor can handle 300BLK it will be able to handle 338 ARC.
338 ARC has an operating pressure of about 30K PSI for subsonic rounds, and 52K PSI for supers if you want to verify with your suppressors manufacturer for compatibility.
45 Caliber Suppressors for 338 ARC
The 45 Cal large bore silencers will work great on the .338 Arc, if you already have one of these universal cans in your safe, you’ll be good to go. The appeal of big bore silencers is that they can be used on nearly any cartridge, 338 ARC included!
Great 45 Cal silencers include:
9mm Suppressors for 338 ARC
One major benefit of the 338 ARC is that it can be used in many 9mm suppressors, so long as they are rated for 8.6 or 300BLK pressures. This opens up the compatibility of 338 suppressors and gives you a ton of awesome options. Becuase the bores are similar .338 -.355 we would expect great performance out of these silencers.
338 ARC compatible 9mm silencers include:
338 caliber Suppressors
If you want to use a dedicated .338 ARC suppressor, there are options for that as well. 338 class silencers have gained popularity recently due to 8.6 Blackout’s popularity, and these same silencers will work great on the 338 ARC guns.
Top 338 ARC silencers include:
338 ARC Parts Compatibility
One of the key advantages of the 338 ARC is its compatibility with existing AR-15 components. All standard AR-15 lower receivers are fully compatible with the 338 ARC upper receivers, making it an excellent choice for shooters who already own AR platforms and want to upgrade without having to replace their entire rifle. Just build a 338 ARC upper receiver and you’re good to go!
The 338 ARC will use the type 2 bolt face, just like the 6 ARC does. These bolts are commonly available, work in standard bolt carrier groups, and have been very reliable.
Additionally, the 338 ARC uses 6.5 Grendel/6ARC magazines, which are widely available and easy to source. The ability to adapt your current AR-15 setup to fire 338 ARC is a significant cost-saving advantage. You won’t need to purchase a whole new firearm system, as you would with some other specialty cartridges.
For those looking to upgrade their bolt-action rifles, the 338 ARC can also be used with popular mini-actions or short-action systems. This versatility ensures that whether you’re a fan of semi-auto or bolt-action rifles, the 338 ARC will fit right into your collection.
Currently, companies such as PWS, Faxon, and KAK Industries plan on building 338 ARC rifles in a variety of barrel lengths, from 10.5" SBRs to 16" rifles. I suspect that we will soon see micro and short-action 338 ARC bolt-action guns as well, which will maximize sound performance even more.
Conclusion
The 338 ARC is shaping up to be a game-changer in the world of hunting, and tactical use. Its balance of power, compatibility, and versatility sets it apart from many of the popular cartridges on the market today. Whether you're looking to expand your hunting range, enhance your tactical capabilities, or simply experience the superior ballistics of the 338 ARC, this cartridge delivers on all fronts. With options for both subsonic and supersonic loads, compatibility with AR-15 platforms, and excellent suppressor performance, the 338 ARC truly represents the future of adaptable, high-performance shooting.
