ATI Omni Hybrid .410 AR-15 Review

I love my little girl more than anything in the world. At 12 years old (13 by the time this magazine hits the shelves), she is my adventure buddy. Hiking. Trail running (not her favorite). Rappelling. Whitewater kayaking. Shooting. Taylor Swift concerts (not my favorite). Regardless of the activity, any day spent with her is a good day. So, when Editor Vincent DeNiro asked me to review the ATI Omni Hybrid AR-15 in .410 shotshell, I saw a golden opportunity. Chloe is a fine shooter with a pistol and can hold her own on the steel targets; a SIG P320 Compact in 9mm is her favorite. She is not quite as good with a rifle or a shotgun, as the weight and recoil sometimes detract from the experience. From the first time I picked up the Omni, I knew this was a platform she would enjoy shooting.

I will admit that I was more than a little biased about the ATI Omni. I was fully prepared not to like it. When the Omni .410 was first released as just an upper back around 2010, it had more than its fair share of problems. DeNiro received one from the owner of ATI, Tony DiChario, back around the time of its introduction and felt that it would be a great option for his two boys to hunt deer with, since Ohio was shotgun-slug only back then. Since both boys had AR-15s at the time, this was a no-brainer but my editor soon discovered a few problems. First, the charging handle was made from plastic with just a thin metal support bar in the middle of the plastic. This did not hold up to winter cold and eventually broke. It would seem a quick fix—just get an AR-15 charging handle and drop it in, right? Wrong. The milled-out channel for the handle was not to AR-15 spec and was too narrow, so DeNiro milled it out so that a standard AR-15 aluminum charging handle would work. Second, the front sight was made entirely from plastic and was pressure fit to the barrel and would get knocked to the left or right if it hit something in the woods, like trees. The fix? He just added an optic, so an older Burris 4x fixed short scope was mounted. Third, there were occasional feeding problems, not many, but they were there, and in the thick woods of Ohio, you really need fast follow-up shots. So DeNiro got out the Dremel tool and made some minor modifications. After that, the first-generation ATI .410 upper was humming along nicely. We will get back to the DeNiro hunting results in a bit, and now on to my thoughts on a .410 shell semi-auto AR-15.

I didn’t really see the need for an AR platform in .410. I was looking forward to this review almost as much as the ACLU was looking forward to the next episode of “Rosanne.” And then I remembered that I get paid to shoot and give my opinion (both of which I like to do…a lot), and that made me feel a whole lot better.

But before we talk further about the platform, what about the .410? Should you consider it as a viable round for hunting mid-sized game? What about home defense? Why should you consider it at all? The .410 shell is actually quite controversial when it comes to hunting. And just to be clear, I’m talking about hunting deer in particular, and not small game. Approximately half the states in the United States allow for the use of a .410 shotgun when deer hunting, while almost a quarter of the states require a hunter to use only shotguns to harvest deer (either the state as a whole, or specified regions within the state). The .410 is also not a “.410-gauge,” as it is a caliber, so we will refer to it as a .410 shell, or just .410. If it were truly measured as a “gauge,” it would be something like a 67-gauge.

For those of you who are blessed to live in a state where hunting deer involves the use of shouldered, centerfire rifle cartridges, “shotgun-only” regulations typically stem from population density issues and/or flat terrain. It seems that the idea of somebody using a .338 Lapua to bag Bambi in suburban Chicago makes some bureaucrats a tad bit nervous…not that anyone in the Chicago area would be allowed to own a firearm with either the letters “A” or “R” in its name. Despite the fact that numerous deer have been harvested over the decades with the .410 shell (the round dates back to 1874, in centerfire configuration), there are many hunters who consider the round to be entirely inadequate and inhumane. Of course, this is just opinion, and Plato said that opinion is the medium between knowledge and ignorance. So, do the facts back up this line of thought? They absolutely do…and don’t.

A .410 Winchester Super-X 2.5-inch shell with a 1/5 oz. slug (which we used in testing) generates 1,830 fps of velocity and 651 ft. lbs. of kinetic energy at the muzzle. This is actually better than a .357 Magnum (a popular hunting round in some parts of the country and a well-respected man stopper) and a bit less than a .41 Magnum. By comparison, the .357 (from an 8-inch barrel) using a 140-grain bullet generates 1,440 fps and 644 ft. lbs. of kinetic energy at the muzzle. The .41 Remington Magnum using a 210-grain bullet produces 1,300 fps and 788 ft. lbs., respectively.

And don’t even ask about the .45 ACP, you 1911 guys; it’s not even in the same conversation as these rounds. If you were to use a three-inch .410 shell with a ¼ oz. Brenneke slug and a 24-inch barrel, your kinetic energy at the muzzle would go all the way up to 788 ft. lbs. But we can’t, as the Omni can only use 2.5-inch shells and has an 18.5-inch barrel. On the surface, it would seem like the .410 shell is more than adequate for the task at hand. However, that is not the whole story.

The problem is that all this data is recorded at the muzzle, and the chances of you shooting a deer at zero yards is neither very realistic, nor very sporting. The truth is the .410 round suffers badly in performance the farther you get away from the muzzle. At 50 yards, that slug that was at 651 ft. lbs. of kinetic energy is now at 338 ft. lbs. At 100 yards, it is at a meager 204 ft. lbs. The .357 Magnum? It still retains 510 ft. lbs. at 50 yards and 414 ft. lbs. at 100 yards. Heck, even the .45 ACP retains 317 ft. lbs. at 100 yards with a 230-grain bullet. As for how the .410 compares to the 20-gauge and the 12-gauge, check out the chart. It is not even close. Another thing to keep in perspective is that at the muzzle, out of an 18-inch barrel, the .357 Magnum will be screaming along at over 1,900 fps and have the muzzle energy of over 1,100 ft. lbs. with that same 140-grain bullet mentioned earlier!

The .410 achieves its respectable muzzle energy via a high velocity. However, it uses a light slug, 1/5 oz. = 87.5 grains. As a result, the kinetic energy bleeds off very quickly. Also, as a result, and due to the design of the Foster slug, the round tends to fragment when it hits relatively solid resistance, like a shoulder blade. This fragmentation can lead to a lack of penetration that is often needed to bring down a good sized, midwestern deer. Can a .410 be used for deer? Yes, it can. But you had better be inside 50 yards and you had better make sure your round(s) is on target. Shot placement is everything.

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So, what were the results of hunting at the DeNiro homestead with the earlier version of the ATI .410 Omni? In 2016, during Ohio’s youth deer-hunt days, DeNiro’s younger son Matthew (12-years old at the time) went out to his favorite hunting spot, which is in a hollow on their property. About 45 minutes before sunset on the second and last day, he saw a four-point buck headed in the direction of where deer usually feed at the bottom of the hollow. He moved several yards to get a better shot in the heavily wooded area and ended up taking his first shot at about 38 yards. The deer was hit in the rear quarter and ended up crawling about 10 feet. Another shot stopped the deer in its tracks, and a third round finished it off. It was his first buck, a four-point buck, and he will never forget that the first-generation ATI .410 upper came through for him—over 50 lbs. of meat for his favorite dinner: tacos! Ohio only allows three rounds total for deer, and there was a mix in the chamber and magazine: Remington flat-nosed rifled slug, Winchester Super-X hollow-point rifled slug, and Brenneke Close Encounter slug. They are not sure which one went first.

As for home defense, the .410 is a suitable choice for those of limited strength, of smaller stature, or averse to recoil and noise. Its ballistics inside of 10 yards are quite excellent, and the round is very user-friendly. Some women, older kids, the elderly, and those with certain strength impairments may want to consider a home defense shotgun in .410. Loaded with self-defense-specific loads, a .410 is very effective in close combat. Is it a 12-gauge? No, it is not. But a 12-gauge is not exactly very user-friendly.

First Impressions

When I first saw the Omni in the box at Blue Line Ltd., my local FFL, I thought, “That looks exactly like an AR in 5.56.” And I mean exactly. From controls to the magazine, to ergonomics and dimensions, there is absolutely nothing about this platform that says “shotgun.” The gun was well laid out (just like an AR) and well executed. Sure, the lower receiver has some screws where ARs normally have pins, and the upper has a roll pin where there typically is none, but I fooled several people into thinking it was just another AR. The finish is flawless and completely consistent, regardless of the material it is covering. The one exception is the 18.5-inch, Turkish-made barrel; it is glossy black, while the remainder of the firearm is matte. The steel-reinforced, polymer lower is made in South Carolina, and the Omni is assembled in Summersville, SC, as well.

The upper receiver is aluminum and has a forward assist, brass deflector and dust cover. There are no sights supplied with the gun, but the full-length Picatinny rail will accommodate irons or optics. It has a 13-inch KeyMod hand guard, but only the forward six inches are available for attachments. The muzzle has a bird cage-style flash suppressor and can accommodate screw-in choke tubes that are sold separately for $99. The charging handle is compatible with any other AR. The pistol grip and adjustable stock are both functional, yet budget, models. There is a single-point sling attachment at the back of the receiver, which is a nice touch.

The Omni balanced right at the front of the mag well and felt far lighter than its advertised weight of 6.5 lbs. Of course, with the supplied five-round magazine loaded and inserted, the platform would weigh far less than a comparable AR loaded with 30 rounds of 5.56.

The magazine is polymer and inserts cleanly and drops freely. ATI makes a 15-round magazine that is available for $29. The controls were all very stiff, especially the charging handle, but would loosen up to appropriate levels in fewer than 100 rounds of shooting. When the dust cover pops open, you can see right away that the BCG is cut differently than its 5.56 cousins. Disassembly is the same as with any AR (for the upper, lower and BCG), with one exception: There is an “ejector arm” at the back of the upper receiver that must be lifted on its hinged assembly to allow the bolt carrier group to slide out.

The biggest difference between the Omni BCG and any other low-priced AR is that there is no gas key, as this is a gas-piston gun. Cleaning the gas system is a real pain in the butt, as you have to remove the flash hider, the handguard and the gas bonnet cap. This level of maintenance requires the use of three different tools; something I absolutely abhor in a weapon. I am certain that it is due to this level of inconvenience that ATI recommends you only clean the gas system once every 1,000 rounds. Interestingly enough, the manual recommends the same for the bolt assembly and chamber. That is a lot of rounds! And shotgun shells aren’t known for their cleanliness. Since this is a review and not a torture test, I did not fire 1,000 rounds through the gun to see if functionality would be affected by their proposed maintenance schedule.

One of the coolest things about the ATI Omni is its versatility. It is called “hybrid” for a reason; it is meant to be multi-caliber capable. The .410 upper will fit and function on any mil-spec AR lower. Conversely, the Omni lower will work on any 5.56 or .300 Blackout upper. How about that for flexibility?!

The Range

As per my SOP, I did not clean the gun, nor lubricate it prior to firing. I first mounted my trusty Vortex Strike Fire (I swear that thing is darn near indestructible), loaded up five rounds of Federal Premium #9 Target Loads, and went to work. The first five rounds were a functions check and were conducted in a very controlled manner. After that, it was game on! Each five-round mag emptied as fast as I could pull the trigger. My only regret was that ATI had only supplied me with a single five-round magazine! One note on that: Loading the magazines was not nearly as quick as loading a 5.56 mag. The rim of the next round tended to catch on the top of the brass of the previous round as it was being seated. A careful eye to technique helped to alleviate, but not eliminate that. At one point while I was loading, I felt a gentle tap on my shoulder. It was Chloe with a look in her eye that said, “Why did you even bother to bring me to the range if you were just going to have me stand here?” And with that subtle reminder, I relinquished control of the Omni to her capable hands. After a quick familiarization, she was doing mag dumps with a smile on her face bigger than my own! She had no problem managing the controls, the weight, or the recoil of the Omni.

It was time to quit wasting free ammo and get down to business. Settling onto the bench, I sighted in the Strike Fire at 25 yards. Once completed, I moved back to 50 yards for accuracy testing. Between the smoothbore barrel, the Foster slugs, and the lack of energy beyond that distance, I figured 50 yards was appropriate. I did not give the Omni the best possible opportunity to shine on precision. I shot from off of a small pack, not a rest, and the red dot was not the best choice for accuracy, but I wanted to approximate what one might use during hunting season, and there ain’t no Ransom Rests in tree stands.

I fired both Remington Express and Winchester Super-X 2.5" 1/5 oz. rifled slugs. They each got one single five-shot group to shine. I measured the groups center-to-center and gave both complete group measurements and removed a flyer from each group to account for the fact that sometimes I am just not very good. The almost six-pound trigger had almost no take up and broke relatively crisply, despite the weight, and did not impede accuracy. The Remingtons produced a group of 6.5 inches (4.3 inches) and the Winchesters measured 5.5 inches (4.2 inches). Next, I moved to 10 yards and broke out the personal-defense ammo. The Winchester Super-X 000 Buck with three pellets gave me an average group of 2.6 inches, and the Winchester PDX1 Defenders, with three discs and 12 pellets, the PDX1 produced an average measurement of 4.0 inches.

The Omni ran flawlessly and fired everything we could stuff down its gullet…right up until it didn’t. Just after the 79th round (a Winchester PDX1), I experienced a failure to feed. No sweat. I ran an immediate action drill and I was right back in the fight. Another failure to feed. Now a remedial action drill, but even that did not alleviate the situation. Rounds simply would not chamber. Examining the bolt face closely, my friend Bud Gane noticed the ejector was jammed in the open position. Expecting the worst, we discontinued the firing for the day and adjourned to Bud’s house, which is equipped with more gunsmithing tools than Brownells. We disassembled the Omni and were about to tear down the BCG when something fell out of it, and the ejector was magically back in the proper position. Examining the small mystery object, we immediately saw that it was a primer and breathed a deep sigh of relief that it was not a broken piece of Omni.

Reassembling the ATI, we grabbed some ammo and went to the back yard to resume some informal testing. I loaded the magazine, inserted it into the mag well, released the bolt, and the round would not chamber. DAMN! Unloading the Omni, I more closely examined the chamber. Guess what I discovered that day. Winchester PDX1 shell “brass” is the exact same shade of black as the chamber of an ATI Omni Hybrid. Upon firing the 79th round, the primer blew out of the shell, the shell jammed in the chamber, and the extractor tore right through the shell rim. Returning once again to Bud’s basement lair?, we retrieved a cleaning rod and popped the meddlesome shell out of the chamber. Returning to the backyard and reloading the shotgun, we resumed firing with no further incident. The Omni devoured everything without a hitch, despite the fact that the manual says the gun needs a 500-round (500!) break-in period. One small issue we did discover while we had the Omni torn down was that the retention clip on the dust cover was missing. Whether it fell off during firing, or was shipped without one, I will never know.

It deserves to be noted that Editor Vince DeNiro’s younger son, Matthew had an opportunity to take a second deer in the 2016 hunting season about a month after he took his first buck. He took careful aim, carefully squeezed the trigger, and got a loud click for his efforts. (One of my fellow instructors likes to say that the two loudest sounds in the world are a gun that goes “bang” when it is supposed to go “click,” and a gun that goes “click” when it is supposed to go “bang.”) This happened a second and then a third time before the deer trotted off. Tearing the first-generation ATI .410 upper shotgun apart, Vince discovered a primer lodged in the trigger assembly, keeping the hammer from making contact with the firing pin. That primer came from a Winchester Super-X 2.5-inch slug.

Final Thoughts

Despite my preconceived prejudices, I developed a real affinity for the ATI Omni Hybrid AR-15. It was a joy to shoot and functioned flawlessly (discounting that one, rogue round). Its price is right, and it has a limited lifetime warranty. Its light weight and short length-of-pull, thanks to the collapsible stock, are ideal for those of small stature. The audible signature and muzzle blast are also relatively polite; something to consider in a weapon intended for home defense. It really would be an ideal home-defense or hunting weapon for those very young, very old, or lacking the strength to handle the weight and recoil of something more robust. Most importantly, it is Chloe-approved. And that means more to me than anything in the world. 

OMNI HYBRID AR-15 .410 SPECIFICATIONS

• Type: Short-stroke, balanced gas system, semi-auto
• Caliber: .410
• Capacity: 5 and 15
• Barrel Length: 18.5"
• Overall Length: 34.9" (stock fully collapsed)
• Weight (unloaded): 6.5 lbs
• Sights: None
• Trigger: 5 lbs 11 oz
• Stock: Adjustable M4
• MSRP: $599
• Warranty: Limited Lifetime
• Manufacturer: American Tactical, AmericanTactical.us

I would like to thank the following entities for the assistance they provided in writing this article:

• American Tactical; 800-290-0065 / AmericanTactical.us
• Federal Premium Ammunition; 800-379-1732 / FederalPremium.com
• Blue Line Ltd.; 330-360-8310 / BlueLineLtdOh.com
• ATG Worldwide, Inc.; 330-964-0311 / MyATGWorldwide.com