HM Defense Defender M556L AR… SHTF-Ready!

Images by the author

When it comes time to buy an AR-pattern rifle, many options abound. You can spend as little as $400, or if you want something more, the sky’s the limit for custom models. I have reviewed many ARs over the years, and I can tell you that price usually – not always, but usually – makes a difference. I’ve seen some pretty nice examples of the breed at both ends of the price spectrum, but generally speaking, you get what you pay for.

Today, we have a mid-priced rifle to consider. This is the HM Defense Defender M556L.

In my rather descriptive title above, I mention that the Defender would make an excellent last-resort, grab-and-go AR for an emergency situation. Read on to see why I feel that way.

HM Defense is a manufacturer located not far from my area, in Ohio. They do a lot of defense and military work, and provide (among other things) .50BMG sniper rifles. One of our sons has a father-in-law who bought one… You can read that review here. That big .50 is truly a thing of beauty! 

Their ARs are made to the same quality level as the .50. I can almost hear you thinking, “That’s great, but what sets this rifle apart from others?” There are a few touches that set this rifle apart… two of them have been awarded patents.

Monobloc Barrel

The first is the Monobloc barrel. This barrel’s gas block is not attached after the fact, but is machined with the barrel. There is nothing to work loose here. They are made in three lengths: 9.5″ (carbine gas system), 12.5″, and 16″ (mid-length gas systems). You can buy a replacement barrel… see the website for details.

Clay at HM Defense sent me, in addition to the rifle, a separate barrel and bolt for illustration purposes, so let’s look at them now. These are photos of the actual parts, not taken from a website. The barrel and bolt are both 100% Mil-Spec compatible, if you were wondering.

Notice: no screws or other attachments in the gas block. It’s integral to the barrel.

HMB Bolt

The other patented item is the bolt. Typical AR bolts have a hole running through them for the cam pin. I haven’t had it happen, but I have heard of bolts that failed… they cracked at that hole when overly stressed. HM Defense solved that problem by developing what they call their Mission-Critical HMB bolt.

This bolt’s cam pin cutout is a “well” machined into the bolt. It doesn’t go all the way through. That adds strength where it’s needed. This bolt is available from HM Defense for $125 to add to your existing AR; it is fully compatible. Or, you can buy the complete bolt carrier group for $175.

Now that we’ve seen a couple of items unique to this AR, let’s review additional specifications and features.

Specifications

• Barrel – the Defender M556L features an HM MONOBLOC barrel with an integrally machined gas block. Chambered in 5.56 NATO/223 Rem, the 4150 chromoly barrel is 16 inches in length, features a 1:8 twist ratio, and utilizes a mid-length gas system. All HM Defense barrels are match grade, triple-honed, and button rifled for superior accuracy.
• Rail – the Defender M556L uses a custom HM Defense 15-inch free float 1913 Picatinny rail, CNC machined from 6061 T6 aircraft-grade aluminum. The rail is compatible with a receiver with a type III Class II hardcoat black anodized finish.
• Lower Receiver – the Defender M556L features a Mil-Spec forged 7075 T6 M4 lower receiver with Type III Class II hard-coat black anodized finish.
• Upper receiver – Defender M556L featured a Mil-Spec forged 7075-T6 M4 upper receiver with Type III Class II hard-coat black anodized finish, M4 feed ramps, and a 1913 Picatinny rail flat top.
• Weight – 6 pounds, 11 ounces.
• Length – 34.25 inches.
• Components – HM defense rifles include an M16 bolt carrier group and Mil-Spec components, including the trigger and fire control group, charging handle, and buffer tube/spring.
• Custom trigger guard, Monobloc dust cover, CNC-machined muzzle brake.
• End plate – HM defense rifles feature a custom quick disconnect (QD) end plate.
• Furniture – rifle features a black Mil-Spec HM stock and Magpul MOE grip.
• Magazine – a 30-round magazine is included with each rifle.
• Made in America (Ohio)
• MSRP: $1295

“Nice Touch” Department

One of my favorite Christmas videos is “A Garfield Christmas”. His comment, “nice touch” when the tree is lit, says it all. I have a couple of “nice touches” I’d like to include about this rifle…

First, the butt stock. I know, it’s a multi-position AR stock, but it’s really nice. In addition to its ambidextrous, QD-compatible features, it has a rubber butt pad. This is uncommon in most ARs. I really appreciate it, not because of recoil reduction (it is only a 5.56, after all), but because the pad “sticks” to your shoulder. It’s easy to hold the rifle in place with one hand, if necessary. A regular, “slick” polymer stock won’t do that.

Next comes the finish. This Type III Class II hard-coat anodized finish is tough. Also, many ARs I’ve handled may catch your glove or hand on the M-LOK forend cutouts … you know, just a bit rough … but not this one. My engineer/AR-loving son commented on how smooth and well-finished the forend is. That’s usually not something that happens on inexpensive rifles, and it’s definitely appreciated here.

Speaking of gloves, if you need to wear them, you’ll find that the trigger guard is curved and lowered to allow access to the trigger. The straight ones may or may not allow access to gloved hands. 

Lastly, here’s an intangible. This rifle just feels nice in my hands. I’ve handled some that I really couldn’t wait to put down. I don’t know if it was the balance, the weight, the roughness of a semi-finished forend… something just didn’t feel right. I have zero issues with this rifle. I could see having it along with me for forays into the woods, or for some informal target shooting. Add a sling, and you’re good to go. Another purpose might be the “magic” two weeks in November in Indiana, deer firearms season. We’ve legalized centerfire rifle cartridges of .219 caliber or larger, so the 5.56 caliber falls within that range. I’m not sure I like that, but they didn’t ask me… 

Photos

Let’s look at some photos I took.

Here we see the Magpul MOE grip

The buttstock features ambidextrous QD-compatible features, and a decent rubber pad

Notice the SME tactical foregrip with light. I set the rifle up with both a scope and this foregrip… I wanted something that I could use for precision shooting, but that also had a foregrip. The jury’s out on whether the foregrip will stay on this particular rifle…

The scope is a Burris Fullfield 3-12×42. I could’ve put a red dot on it, but I wanted something a little more precise. As with the fore grip, I’m not sure if this scope will live on this rifle… I needed something to put on it to get some shooting done for this review. If I keep any kind of “normal” scope on it, I’ll get a handle extension. Reaching it under the scope is not fun.

Range Time

Black Hills supplies my 5.56 mm ammo, and good stuff, it is for sure. They sent me the following loads to shoot in this rifle:

• 50 grain Optimized TSX;
• 62 grain Dual Performance;
• 77 grain OTM

I went to my backyard range. I had a tree come down in front of my 100-yard target spot, so I’ve had to shorten the range a bit… I can get to 80 yards, at least. I waited for the arctic conditions to clear – six inches of snow in December, rare in the Hoosier state. On the first day that allowed it, I grabbed some targets and headed to my abbreviated range.

Before you can shoot, you have to load magazines… duh! Here is a good spot to mention an accessory that no AR shooter should be without. There are several magazine loaders available, but the Caldwell makes it easy to load a box of 20 cartridges into a 20- or 30-round magazine without issues. I had the 50-round boxes that Black Hills uses, but even so, it worked out great. Just insert ten cartridges nose-down into each of the three slots, attach a magazine to the end, and push the charger lever in. It shoves ten rounds in slicker than a whistle. Repeat twice more for a 30-round magazine. There’s a link below.

Back to the range. The trigger was excellent; it broke at an average of 5.5 pounds, with very little take-up and no creep. The Fullfield 3-12 scope was up to the task. I placed the rifle on Birchwood Casey-filled bags and conducted some shooting. There is an advantage to using my quirky tactical foregrip/light: it can act as an improvised monopod and serve as a solid support point for your weak hand. Even so, for this little trial, I used a couple of Birchwood Casey filled bags. As noted above, I may or may not leave it on this rifle. We’ll see.

Here are a few targets, in order of bullet weight: 50, 62, and 77 grains. It really liked the 62. The conditions were not ideal, but I was eager to shoot it. We have three points of impact because I was adjusting the scope.

I think that, after things warm up, I’ll shoot it more just for fun. Then, I’ll have whatever optic I put on it truly zeroed and will have a more complete picture of the finished rifle. As it is here, it’s not bad at all. This rifle shows strong potential for accuracy.

Conclusion

HM Defense built its reputation by producing high-quality firearms for both military and civilian markets. Using top-notch materials put together by people who know what they’re doing means that if you buy a rifle from them, you’re going to get your money’s worth. The patents for the monobloc barrel and HMB bolt don’t hurt, either. I mentioned above my son’s father-in-law. He is a retired engineer and has a keen eye. He is impressed with his .50’s build quality and attention to detail. This AR shows those same traits.

Want an integrally suppressed AR? They make two of them. Have the noise reduction without the big lump on the end of the barrel. This is a company on the cutting edge of technology. For that reason, you might want to consider them if you want to add an AR to your collection.

And, Heaven forbid that you should ever actually need an SHTF rifle, but I believe this one would work well in that scenario. 

Links To Items Used In This Review 

• Birchwood Casey Shooting Bags Filled, $40
• Birchwood Casey Range Cleaning Kit, $60 
• Black Hills Ammunition
• Caldwell AR-15 Magazine Charger, $55
• Caldwell E-Max Low-Profile Hearing Protectors, $33
• Caldwell Ultimate Target Stand, $33
• GPS Medium Range Bag, $150 
• MTM Case-Gard High-Low Shooting Table, $160
• Wheeler Firearm Accurizing Torque Wrench Kit, $88
• Wheeler Trigger Pull Gauge, $88
• Wheeler Red Laser Bore Sighter, $193 (available in green, also)