62-Grain 5.56 Ammo: Your Top Questions Answered

The shooting industry is not without its heated debates, and one of those revolves around 62-grain 5.56 ammo. 

Barrel twist, accuracy, M855 green tip, and whether it performs better than 55-grain or even some heavier 77-grain ammo.

Is 62-grain 5.56 worth the hype? Let’s clear the air and break it all down.

Is 62-grain 5.56 ammo more accurate in an AR-15?

That depends on your rifle’s barrel twist rate. Many AR-15s with a 1:7 or 1:8 twist are designed to stabilize heavier bullets like the 62-grain. 

In those setups, 62-grain ammo can be more accurate than lighter 55-grain rounds—especially at longer distances or in windy conditions. 

Solid copper options like HOP Munitions’ 62-grain REX rounds take it even further with consistent expansion and energy transfer for shooters looking for precision and terminal performance.

Will 1 in 9 twist stabilize a 62-grain 5.56 bullet?

Yes, a 1:9 twist barrel will stabilize most 62-grain bullets just fine. While it’s not ideal for bullets much heavier than 70 grains, 62-grain is right in the sweet spot. 

You’ll get good accuracy and reliable flight—especially with high-quality rounds.

Can you shoot 62-grain 5.56 through a 1/7 twist barrel?

Absolutely. A 1:7 twist rate was originally designed to stabilize heavier projectiles like tracer rounds and 62-grain bullets. 

Many military-style AR-15s come standard with this twist rate. So yes—62-grain ammo performs very well in 1:7 barrels.

What is the best rifle twist for 5.56 62 grain?

The best twist rate for 62-grain 5.56 is generally 1:7 or 1:8. These faster twist rates give the bullet enough spin to stay stable in flight. 

While 1:9 can also work, you’ll likely get tighter groups with 1:7 if you’re shooting high-performance loads like HOP Munitions’ 62-grain Solid Copper REX, which is designed for both accuracy and terminal effectiveness.

How thick of metal can a 5.56 62-grain green tip go through?

Green tip (M855) 62-grain rounds have a steel penetrator core and can punch through ¼-inch mild steel at close range. 

However, don’t expect them to consistently pierce armor plating or hardened steel. And keep in mind—not all 62-grain bullets are green tip or steel core.

What is the difference between 55-grain 5.56 and 62-grain?

The main difference is bullet weight and performance. A 55-grain 5.56 round is lighter and generally a bit faster, making it a solid choice for short—to mid-range shooting and budget-friendly practice. 

The 62-grain version is heavier, offering better stability in wind, improved penetration, and more consistent performance at longer distances—especially when paired with the optimal twist rate. 

If you’re hunting or want better energy transfer on target, a 62-grain solid copper round (like the HOP Munitions REX) will hit harder and expand more effectively than a standard 55-grain FMJ.

5.56 55-grain or 62-grain for practice ammo?

If you’re just punching paper or running drills, 55-grain FMJ is cheaper and does the job. But if you want your training to mimic your defensive or hunting ammo, running 62-grain—especially something like the HOP REX—makes sense for consistency in recoil and zero.

Can you shoot 62-grain 5.56 through a 1/7 twist barrel?

Yes, and it’s often the ideal twist rate. 

A 1/7 twist rate stabilizes 62-grain bullets very well. Military rifles and modern AR-15s commonly use this combo.

Are you allowed to hunt with a 5.56 62-grain bullet?

It depends on your state’s hunting regulations, but in many areas, you can use 62-grain 5.56 rounds for hunting. 

Be sure to use a hunting-specific bullet like HOP Munitions’ Solid Copper REX. It is designed for controlled expansion and deep penetration—perfect for hogs, coyotes, and similar game.

Can you hunt deer with green tip 556?

Technically, yes—but it’s not ideal. Green tip (M855) is made for penetration, not terminal expansion. It may zip through a deer without transferring enough energy. 

A solid copper expanding bullet, like the REX round from HOP Munitions, is a far better ethical choice for clean kills.

Does the military use 5.56 55 grain or 62 grain?

Both. The U.S. military initially issued 55-grain M193 but later transitioned to 62-grain M855 green tip for better penetration. 

Specialized units also use rounds like the MK318, a 62-grain open-tip round, which inspired next-gen designs like HOP’s 62-grain REX.

How much does a 62-grain 5.56 round weigh?

The bullet itself weighs 62 grains, which equals about 4.02 grams. The complete round—case, primer, powder, and projectile—weighs roughly 180–190 grains total, depending on load specs.

Who makes the best 5.56 ammo out there and 62-grain?

There are plenty of great manufacturers, but if you’re looking for cutting-edge performance, HOP Munitions’ 62-grain Solid Copper REX is one of the best in the game. 

Inspired by the legendary MK318, it delivers tight groups, deep penetration, and devastating energy transfer, all in a lead-free expanding projectile.

How far can 62-grain 5.56 can shoot?

The effective range of 62-grain 5.56 is about 500 to 600 yards for target shooting, depending on your rifle and conditions. 

For hunting or defensive use, a more practical range of 300 yards or less is needed to ensure reliable terminal performance.

Is all 62-grain 5.56 steel core?

Not at all. Only M855 “green tip” has a partial steel penetrator. Other 62-grain rounds—like soft point, hollow point, and solid copper like the HOP Munitions REX round—do not have steel cores and are built for different purposes, like hunting or defense.

Is 62-grain good for self-defense?

Yes—especially if you use a purpose-built expanding bullet. HOP Munitions’ 62-grain REX is a great example, designed for controlled expansion and energy dump on impact. 

Unlike FMJ or green tip rounds, it won’t over-penetrate, making it a smarter choice for defensive use.

Is 62-grain 556 armor piercing?

No, the ATF does not classify 62-grain rounds as armor-piercing. Even the M855 green tip, which has a mild steel core, doesn’t meet the criteria for AP ammo. 

Solid copper expanding rounds like the HOP REX are lead-free and legal in all 50 states.

Final Thoughts

Whether dialing in your zero, prepping for a hog hunt, or building out your defensive carbine, 62-grain 5.56 ammo offers an outstanding balance of penetration, accuracy, and terminal performance. 

And when you’re looking for something that performs beyond expectations, HOP Munitions’ Solid Copper REX gives you the punch of the MK318 with modern upgrades.