AR-15 Built For 3-Gun

  • Built for 3-GunCompetitions
  • Constantly evolving build
  • Chambered in 5.56x45mm

It’s not often that we get to examine, in detail, the personal rifle of a true industry insider. Sure, there are official display guns created by companies that are mocked up with the newest doohickies on it that we routinely see at shows, in shops and online, but we want to know what the people behind the brands really run on their own rifles. Which parts do they choose and why? We got just that chance from Ari Bartolome, Marketing Director at Rainier Arms. 

If you’re unfamiliar with Rainer Arms, we have to ask, have you’ve been living under a rock? Kidding aside, Rainier Arms (RA) started out as an online shop specializing in AR-15 parts and accessories and has steadily grown to be one of the top go to retailers for “high end” and innovative firearms and accessories around. We got to talk with Bartolome, who handles RA’s marketing, to check out his customized AR-15.

As a benefit of his daily grind, he gets to see and handle the latest and greatest gear that passes through RA’s doors. (Must be nice!) If you had access to a metric ton of the newest parts and accessories, how would you set your rifle up? That’s what we’re here to find out. 

Being an avid competition shooter, Bartolome built his AR-15 to compete in 3-Gun competitions. Specifically, he built this rifle to qualify for 3-Gun Open Division matches. Taking a quick look at it, we immediately noticed that he paired up a Seekins Precision billet upper receiver with a Rainier Arms AR-15 UltraMatch Billet Ambi Lower Receiver MOD 3 to form the foundation of the gun. Billet receivers tend to have more uniquely machined contours than forged receivers, which helps gives this build an edgier look.

Inside the upper receiver sits a Seekins Low Mass Carrier. He chose a lightweight BCG because taking quick, accurate shots is immensely important when it comes to competition shooting and a low mass carrier helps him do just that. The result of lowering the amount of mass that cycles through the upper receiver is decreased felt recoil and a muzzle that gets back on target quicker. 

Under the Fortis Switch Rail is a Rainier Arms UltraMatch barrel with an intermediate length gas system in 17-inch length. The combination of the 17-inch length barrel and a longer, intermediate gas system helps further soften the recoil of each shot. He points out that he chose the Fortis Switch rail because, “it’s a solid rail that’s also slim and fits VTAC barricade slots perfectly.” An adjustable gas block by Seekins and a Fortis muzzle brake also help him tame that all mighty 5.56 round even more. As you may have surmised, the name of the game here is to put the kibosh on muzzle rise and to get back on target quickly. 

The lower receiver’s set up is pretty simple but very effective. The Rainier Arms Mod 3 lower contains a CMC 2-stage trigger that is configured for a consistent two-pound pulls on both first and second stages. He swears by the consistency of CMC triggers and has them on all his AR builds. The magazine release is a Rainier Arms EMMR, which features interchangeable finger pads that help extended it for an easier and more consistent reach without the need to break your grip in the slightest. With the rifle constantly evolving, Bartolome points out that newest part on the rifle is the Fortis LA stock. Crafted out of aluminum with a carbon fiber cheek piece, the stock has a rock solid feel and definitely looks sexy.

We commented on the unique three-tone/pattern finish of the gun, which we thought was done on purpose, Bartolome responded, “It’s funny that I really don’t spend a ton of time on my own rifles, making them look super IG worthy and nice.” Continuing about the look of the rifle he commented, “This is an old build, back when the ‘burnt bronze’ Cerakote craze was hot and heavy. It’s really sad, because over time I’ve swapped parts out like my handguard and never Cerakoted it. I couldn’t give my rifle back to get it done as I was always shooting it. I like it anyway and it shoots tight groups reliably so I left that mojo alone.” The original Cerakoted parts were done by Bill Porter of Hyper Ballistics. 

If you take a good look on the Vortex Razor HD Gen II 1-6×24 scope, you’ll notice something mounted to its magnification adjustment ring that allows him to cycle from 1x magnification to 6x with ease. No, it’s not a cattail or a throw lever, but a fishing reel mounting clip called a Breakaway Nylon Coaster. Yes, that kind of fishing. 

Bartolome found that these reel mounting clips could double as a great extended magnification adjustment lever substitute for his Vortex. It actually isn’t much of a secret within the competition community, but we think it’s pretty cool anyhow. It’s made out of nylon so it’s forgiving when he dumps his rifle into barrels and bangs it against barricades at 3-Gun competitions. At about 10-bucks a pop, he says that they’re, “High speed, low budget. I have them on all of my optics now.” Also attached just right of the scope is a Vortex Razor Red Dot in a Razor RT45 Offset Mountwith a large 6 MOA dot for close up shots. 

You’d think that someone that has access to RA’s entire inventory of products would bathe his rifle in Gucci, but no. Aside from his fishing rod-inspired optic throw lever, he also repurposes old parts to get the job done as well. “I use some home remedies in some cases to accomplish the task, like my old Aimpoint QRP mount that I repurposed to sit on my rail and act as my barricade stop. I like it because it’s tool-less and I can use it on the right or left side and it offers good bite on the barricade because of the knurling on the knob.” 

We asked Bartolome who did the work on his rifle. He answered, “I do all of the work myself, I have a full gun bench at home and I’m always tinkering into the wee hours of the night, mostly because that’s when my kids go to sleep. But mostly because I have an over active mind that struggles to turn off at night.” We surely can relate to that.

After chatting with him about his thoughts on outfitting rifles, we learned that he is not in the habit of swapping out parts at the drop of a hat (as some of us might if we worked at a major firearms retailer). It’s quite the opposite actually. “I will run and continue to run what works until it breaks, I don’t often swap parts out on this rifle unless I need to. I have other rifles I use to test new parts I get in from RA to test or evaluate. Training time is so sparse nowadays, it’s easier to keep your gear consistent so you’re not having to retrain how you shoot your rifles.” 

Bartolome continues, “I like what works, and what works at home on the range is different than one that will run in 20-degree weather, and what will run in dry and sandy conditions like shooting out in Utah or Texas in the summer. This is my long winded way of saying, ‘yeah I know it looks hobbled together, but it works, and to me, my favorite view of my rifle is when it’s on my shoulder.’” Indeed, that’s our favorite view too.

This purpose built AR definitely reflects the soft spoken and humble nature of Ari Bartolome. It’s built to work for the purpose of 3-Gun and work well, while keeping the flashiness to the minimum. Thinking creatively about repurposing parts that others might have cast off such as the QRP mount in the place of a barricade stop is an eye opener and refreshing to see. Even with access to it all, it’s Bartolome’s creativity and practicality that makes the difference.

Build Sheet

Ari Bartolome’s 3-Gun AR-15


Caliber: 5.56x45mm

Length: TK – TK in. 

Barrel: 17” Rainier Arms UltraMatch Barrel 

Gas System: Intermediate

Weight w/o magazine: TK lbs. TK oz.


Optic: Razor HD Gen II 1-6×24, Vortex Razor Red Dot 6 MOA

Optic Mount: Bobro Mount, Razor RT45 Offset Mount

Upper Receiver:Seekins Precision Billet Upper

Lower Receiver: Rainier Arms AR-15 UltraMatch Billet Ambi Lower Receiver MOD 3

Handguard: Fortis Switch Rail

Stock: Fortis LA Stock

Magazine: Hexmag

Parts & Accessories: Seekins Low Mass Carrier, Seekins Adjustable Gas Block, Fortis Brake, CMC 2-stage Trigger, Rainier Arms EMMR,Rainier Arms Avalanche Charging Handle, Breakaway Nylon Coasters (optic cat tail), Aimpoint QRP mount (barrier stop), Harris BiPod with a set of spiked feet from Doug Glorfield

Owner: Ari Bartolome

Occupation: Marketing Director at Rainier Arms

Special Thanks: Shout out to some of the best manufacturers of parts that work for “me”: Fortis Manufacturing allows me to test their parts and listens to our needs, CMC Triggers for making some of the best triggers for the AR, it’s like hot sauce, I put that on everything. Vortex Optics for keeping making the most rugged optics in the game. Last shout out to Rainier Munitions for keeping my baby eating and shooting laser beams!

Text and Images by Staff

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