# 6mm ARC vs. 5.56 NATO: Is the 5.56 Obsolete? **URL:** \ **Category:** Public Shooting Range\ **Tags:** 556x45\ **Created:** [November 28, 2025, 4:15pm UTC](https://sixguns.com/t/6mm-arc-vs-5-56-nato-is-the-5-56-obsolete/2111 "2025-11-28T16:15:53Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![Ammodotcom](https://sixguns.com/user_avatar/sixguns.com/ammodotcom/32/1880_2.png) [@Ammodotcom](https://sixguns.com/u/Ammodotcom)\ **Post date:** [November 28, 2025, 4:15pm UTC](https://sixguns.com/t/6mm-arc-vs-5-56-nato-is-the-5-56-obsolete/2111/1 "2025-11-28T16:15:53Z")
The [6mm ARC](https://ammo.com/rifle/rifle-ammo-6mm-arc) is a flat-shooting (and newer) AR-15 cartridge with little recoil. The 5.56 NATO is the standard AR-15 cartridge, albeit not without significant flaws. In this 6mm ARC vs. 5.56 NATO comparison, we’ll learn if the 5.56 has finally been outdone or if you should keep your AR-15 chambered for it. ## Overview of 5.56 and 6mm ARC Ammo The [5.56x45](https://ammo.com/rifle/5.56x45-ammo) is beloved by many firearm enthusiasts (myself included), yet despised by others. It’s utilized by militaries worldwide because it is accurate, low-recoiling, and relatively inexpensive to fire. Civilians regularly use it for hunting (including deer, in some states), home defense, target shooting, and competitive shooting. The relatively new 6mm Advanced Rifle Cartridge (ARC) is a low-recoil, flat-shooting round that’s ideal for long-range target practice. It promises to do what the 5.56 can’t, but it also has some downsides of its own (more on that later). ## 5.56 vs. 6mm ARC Pros and Cons Neither of these rifle cartridges is perfect, as each has significant advantages over the other. | 5.56 | 6mm ARC | | --- | --- | | Pros | Cons | | ✓ Lower recoil | ✗ Steeper trajectory | ✓ Flatter trajectory | ✗ More expensive/limited availability | | --- | --- | --- | --- | | ✓ Inexpensive, abundant ammo | ✗ Less stopping power for hunting/home defense | ✓ Higher ballistic coefficient | ✗ Shorter barrel life | | undefined | ---- | ---- | ---- | | ✓ Longer barrel life | — | ✓ Better for long-range shooting and target practice | ✗ Slightly more recoil | | undefined | ---- | ---- | ---- | | ✓ Established and trusted for decades | — | ✓ More stopping power | — | | undefined | ---- | ---- | ---- | ## 6mm ARC vs. 5.56 Ammo Specs | **Category** | **5.56x45mm** | **6mm ARC** | | --- | --- | --- | | Parent Case | 223 Remington | 5.6x39mm | | Bullet Diameter | 0.224" | 0.243" | | Neck Diameter | 0.253" | 0.274" | | Base Diameter | 0.377" | 0.441" | | Case Length | 1.760" | 1.490" | | Overall Length | 2.260" | 2.260" | | Case Capacity | 28.5 grains H2O | 34.0 grains H2O | | Max Pressure | 55,114 psi (SCATP 5.56) | 52,000 psi (SAAMI) | _Continue reading [6mm ARC vs. 5.56 NATO: Is the 5.56 Obsolete?](https://ammo.com/comparison/6mm-arc-vs-556) on [Ammo.com](http://Ammo.com)_ [https://ammo.com/comparison/6mm-arc-vs-556](https://ammo.com/comparison/6mm-arc-vs-556) ---
**Author:** ![WV460HUNTER](https://sixguns.com/user_avatar/sixguns.com/wv460hunter/32/7579_2.png) [@WV460HUNTER](https://sixguns.com/u/WV460HUNTER)\ **Post date:** [December 1, 2025, 3:48pm UTC](https://sixguns.com/t/6mm-arc-vs-5-56-nato-is-the-5-56-obsolete/2111/2 "2025-12-01T15:48:53Z")
So exactly what makes it inexpensive ( relatively speaking) to shoot,.. is it the production rates at which it is produced or the smaller .224 diameter bullet being less expensive to produce. If I have a projectile that is 150 grains I can get roughly a little over 200 rounds from a 5 pound bar of lead. Versus 300grain projectile yielding slightly over 100 rounds from a 5 pound bar. But with that said its still 5Ib. Bar of lead . More powder more brass and more primers used to make that specific turn of bullets ( assuming the entire batch will be loaded ) I think it is possibly due to how common it is . Definitely cant be much cheaper. ---
**Author:** ![shooterrex](https://sixguns.com/user_avatar/sixguns.com/shooterrex/32/50_2.png) [@shooterrex](https://sixguns.com/u/shooterrex)\ **Post date:** [December 1, 2025, 4:55pm UTC](https://sixguns.com/t/6mm-arc-vs-5-56-nato-is-the-5-56-obsolete/2111/3 "2025-12-01T16:55:03Z")
I can buy 5.56/223 @ less than 50 cents a round. 6 ARC is only loaded by Hornady right now and is over $1.00 a round. The 6ARC is a 1000 yd cartridge. The 5.56/223 is not. ---
**Author:** ![WV460HUNTER](https://sixguns.com/user_avatar/sixguns.com/wv460hunter/32/7579_2.png) [@WV460HUNTER](https://sixguns.com/u/WV460HUNTER)\ **Post date:** [December 1, 2025, 7:50pm UTC](https://sixguns.com/t/6mm-arc-vs-5-56-nato-is-the-5-56-obsolete/2111/4 "2025-12-01T19:50:23Z")
So its the amount of places tooled up to load 5.56 that is making it so friggine cheap ? Still what about all that powder primers and brass . ? ---
**Author:** ![shooterrex](https://sixguns.com/user_avatar/sixguns.com/shooterrex/32/50_2.png) [@shooterrex](https://sixguns.com/u/shooterrex)\ **Post date:** [December 1, 2025, 9:09pm UTC](https://sixguns.com/t/6mm-arc-vs-5-56-nato-is-the-5-56-obsolete/2111/5 "2025-12-01T21:09:03Z")
Brass ,bullets, and primers along with powder have come down. Yes tons of folks loading 5.56/223 and prices have come down.