Ruger AR15 300 blackout review with upgrades ---With Photos :)

So one of the newest members of the family is a Ruger AR15 pistol chambered in .300 AAC blackout. About 2-3 years ago, I started getting into the AR pistol platform and built one, but then sold it to a friend because it just didn’t have a purpose. When I purchase a firearm, it has to serve a purpose. Either it is for home protection, carry, or for just having fun at the range. I had all these bases covered, so it just didn’t have a fit. Fast forward and I started to want something that was small, potentially concealable and had the ability to fit mounted in the hatch of my vehicle. I started searching the web and came across the Ruger.

These are the specs from the factory of this AR pistol:

  • 10.5” barrel length, 1:7” RH twist

  • 5.8 lbs

  • SB Tactical SBA Pistol Brace

  • Max Length 27.6”

  • Free-float 9” M-Lok handguard

  • 9310 allow steel bolt, shot peened and pressure tested

  • Pistol length gas system

  • Cold hammer-forged 4140 chrome-moly steel barrel with a matte black oxide finish

  • M4 feed ramps

  • Chrome plated BCG and gas key

  • 5/8” – 24 threaded barrel

  • Retail price $ 705.99

This seemed like a great base to start a build off with. Not able to leave anything stock, some items were added to improve reliability and comfort.

The first item added was a Young Manufacturing M16 hard chrome HMB bolt BCG. The bolt in the BCG is precision machined throughout the heat treat process at the bolt lugs, center support ring, and bolt tail. The bolt has 30% more surface area on the upper and lower guides, improving stability due to the increased contact area. What I have noticed is smoother cycling with this bolt, more consistent ejection patterns, and improved rim engagement. The HMB bolt design increased the structural integrity of the bolt of your standard Mil-Spec, helping to eliminate bolt breakage and failure. Overall, this bolt just devours ammo and keeps coming back for seconds.

A CMC 3.5lb single-stage trigger was added as well. This is always a topic of debate. Swap or not to swap? What are the legal ramifications? Well, I have owned a few firearms with upgraded triggers or trigger jobs, and on the AR15, I just prefer an aftermarket trigger over the standard Mil-spec trigger. I went with the curved trigger as I just prefer the feel on a rifle. These triggers are complete drop in units and have many benefits once installed. The trigger itself has absolutely no creep that I can notice and has an ultra-smooth break and positive reset that I love. Follow up shots during double tap drills are thoughtless and quick and the pull feels consistent through every cycle.

A KAW Valley KVP linear compensator was added as these pistols come with nothing at the end of the barrel. I have always gone with muzzle break on my AR15’s and have been curious on how a compensator would feel instead. The idea behind this compensator is that it sends the gases downrange, decreasing perceivable sound to the shooter and bystanders. The muzzle break on my AR15 M4 carbine is loud as hell. It makes that little 5.56 sound like it is hitting above its weight class. With this compensator, even with ears on, the perceived decibels of the .300 blk are much lower compared to a muzzle break. Another benefit I have noticed is the felt recoil. Compared to other AR platforms I have shot with a muzzle break, the compensator appears to aid with a more fluid and inline recoil. When shooting this and comparing it to my AR15 rifle, I am able to get back on target faster and follow up shots are faster and more accurate, even with the higher grain round.

I also added a BCM gunfighter charge handle and a Magpul handstop. These are all personal preference. I like the feel and positive engagement of the BCM gunfighter charge handle. They are not oversized like some other charge handles, make charging the BCG easier, and have a great reputation. The Magpul handstop is a cheaper alternative to some of the handstops currently on the market. I may upgrade this, but for now I am testing the waters with it and so far I am pleased with it.

I am a fan of Vortex, so installed on this pistol is a Vortex Spark AR. I do like the simplicity of this little optic. Two buttons cycle the on/off function and the dot intensity. My eyes are aging though and I am starting to notice my astigmatism more. If I am not wearing my prescription glasses, I get the dreaded starburst effect. I may consider selling this optic and upgrading to the prism optic instead. Again, that is my eyes and is not a defect in the craftsmanship of the Spark AR. If I wear my prescription glasses, the dot is a solid circle. Whether indoors, in a low light situation, or in the blinding Arizona sun, this little red dot has enough intensity that it is not drowned out. What I do not like is the flimsy protective caps that come on this red dot. On my strikefire II, it has hinged caps that do not flop around like the Spark AR. The Spark AR caps are designed to link together, but that is just another step to go through in a SHTF situation. I have not had an issue at this time with a cap flopping into view, but the potential is always there. I may investigate a solution to this, and if there is no solution, I will be selling this optic in the future and upgrading to an optic with better optic protection options.

So how does the gun function? Well, in one word. Beautifully. Since most of my time on the range has been spent with the aftermarket parts installed, I cannot speak to the “stock” aspect of the pistol. So the following review will be based on this platform with the installed aftermarket parts.

Fit and Finish:

Ruger has done an excellent job in this category. There is no noticeable play in between the upper and the lower and it has a solid joint between the two. The overall finish of the pistol has held up well after multiple trips to the range. There are no odd rattles or wiggles anywhere that I can find. All engageable parts that are factory have a positive feel. The SB tactical brace engages the buffer tube well with no play and the castle nut from the factory appears to be working well. I have not had to go through and tighten anything or consider upgrading due to lack of quality. The only upgrades performed are due to personal preference.


As of writing this review, I have not had a single FTE, FTF, short stroke, or any perceived issue with this pistol at all. As long as a round is in the chamber, you pull the trigger and the gun goes bang. It cycles exceptionally well and the BCG runs through ammo like a champ and provides a consistent ejection pattern. I have cleaned the firearm after every range trip and there is no appearance of any abnormal wear patterns, high spots, or issues with either the upper or the lower. The BCG due to the hard chrome finish is easy to clean. I have also inspected the BCG after each range trip and so far it is as good as the day it was purchased. Compared to a standard BCG, the differences are apparent. The machining is definitely a higher quality, it appears more robust, and the bolt itself just feels better. Especially at the lugs. I would definitely trust this firearm with my life.


I am not using this to hit sub-MOA groups or for any precision purpose. The goal is self-defense, so combat style grouping in the Alpha zone are what I am basing this part of the review on. With that being said, I have tested this in a precision scenario and I can hit sub-MOA groups with this out to 25 yards (75 feet). So yes, this little 10.5” pistol is damn accurate. In regards to a more combat style of shooting, this pistol is a beast. The ammo tested so far has been Fiocchi 125 grain polymer blue tip, Hornady 110 grain BLACK polymer red tip, and Aguila 150gr FMJ. Out of all of the brands fired, I prefer the Fiocchi 125 gr polymer tip and they appeared to have the most consistent accuracy of the group. The Aguila rounds felt “hot” for a 150 gr round. Follow up shots are quick, which I believe is in part to the KAW Valley compensator coupled with the light weight of this pistol. I typically run drills in succession starting at 15 feet and moving the target incrementally to 50 feet. The drill consists of a double tap in the Alpha zone from low ready with safety on, a reload, and follow up shot directed at the T Zone. I am able to cycle this firearm rapidly and effectively with ease. From the low ready position, red dot and target acquisition is fast and the double tap will land in the middle of the alpha zone no matter the range. Follow ups after reloading to the T Zone are quick as well. I have had no random flyers into the B or C zones during any of my drills. The recoil is a solid backward motion with minimal muzzle rise making follow up shots quick and accurate. Basically, wherever I put the dot, that’s where the bullet is going. The red dot has maintained zero since setting and I have had no issues involving accuracy related to this optic.

Differences of 5.56/2.23 and .300 blk:

Really, I do not notice much. There is a little more perceived recoil, but really not much to make a quibble about. I have noticed the small difference because I have shot my 5.56 and .300 blk back to back. But at the end of the day, they are both comfortable to shoot, especially on an extended range day. The reason I chose the AR pistol in .300 blk versus a 5.56 is due to the difference in ballistics. The .300 blackout is great up to 200 yards. This pistol is categorized, by me, as my close quarter, close range self defense weapon if I have my choice between my sidearm and this AR pistol. Basically it is utilized as a bedside firearm and as a car gun. Per American Arms, a .300 blk fired from a 10.5” barrel has almost the same muzzle energy as a 5.56 fired from a 16” barrel. This is the reason I chose to an AR pistol in .300 blackout. The minimal difference in perceived recoil, the muzzle energy created in a short barrel compared to 5.56, and the minimal difference in the price of ammunition are also what drove me to this round. If you want to view the full ballistics report from American Arms, it can be found by following this link:

So would I do it all over again? YES! YES! YES! The more I fire this little AR pistol, the more I love it. The accuracy, portability, maneuverability, fit and finish, as well as the added components make this thing a real shooter. At the end of the day, I have

Links to the build parts:

Ruger AR15 Pistol .300 AAC Blackout

Young Manufacturing HMB BCG

CMC Trigger

Vortex Sparc AR

Kaw Valley Linear Compensator

Magpul Handstop

BCM Gunfighter Charging Handle



Nice review @ThatGuy. It’s a nice looking little pistol.


Very nice
:+1::+1::+1::+1::+1:AND :star::star::star::star::star:


I’m looking to purchase an AR myself and this 300 blackout is a nice looking AR15. You gave a thorough review also. When I’m ready I will remember this post and use it as a guide. Thanks brother.

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Thanks for the review :+1:


Welcome aboard, great review and links, many thanks!!!


So here she is all finished. Really happy with the way this build came out. This thing is definitely a shooter. Just too bad .300 black is so damn expensive. Glad I have a 5.56 carbine for training. I love how this little build is easily transportable.

The remaining items added are as follows.

  • Magpul sling
  • Streamlight ProTac 350 lumen with pressure switch
  • Tacticon 45 degree back up sights

I would give the Magpul sling a 4/5 starts overall. Only reason I didn’t give it 5/5 is due to ease of manipulation regarding length adjustment. Once it breaks in, this should improve but it tends to hang up a bit at both ends of adjustment. The Streamlight gets a 5/5. Lumens are plenty bright with a good flood of light when indoors which is what I wanted this for but still works well outdoors. If mainly for outdoor use though, I would go with a higher lumen output. The pressure switch is fantastic. Easy to manipulate and works no matter where the switch is pressed. The continuous on switch has a positive detent and click. The Tacticon back up sights only cost about $45 dollars off of Amazon and Tacticon is a veteran owned company. I give them a 4/5 due to the ease of use. They are a bit of a pain to manipulate but I keep them in the up position so this isn’t an issue for me. I had them sighted in with about 20 rnds of ammo which is a huge plus. Adjustments are postive with great detent and they in lude a front sight post tool.

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Looks awesome brother and BTW nice piece of hardware brother.

Moved my comment from the other thread
Do you do anything different between your 300/556 rifles to keep track of the calibers? I use lancers for 300 and magpuls for 556 (different color and texture), plus mag bands, plus the dust cover has caliber labels. I think I’ve covered all the bases to make sure I dont accidentally put the right caliber in the wrong rifle, but am always looking for new ways to make it more fool-proof (fool = me).

Where did you order the Magpul sling from? The MS4’s are out of stock almost everywhere I look.

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I use different colored mags for differentiation. Black mags are dedicated for .300blk and tan mags are dedicated for 5.56. I typically only buy Magpul mags as they have never failed me. Just simple color coordination. This makes it fool proof for me. Plus, Becoming familiar with what the rounds look like help. It gets pretty obvious the more you load. I keep both types of ammo in different ammo cans as well that are clearly labeled.

I ordered my magpul sling from optics planet. We get a 10% discount as members. I have the MS3 sling.

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Check ebay for the sling. They have plenty. That has been a go to resource with all the craziness going on.


Thanks @Johnnyq60

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I actually wrote 300 Blackout in huge Gold sparkly fingernail polish on the mags both sides. That’s my workaround until Daniel Defense gets some 300 bo mags out. Nightmare scenario. Home invasion in progress , ask my wife for mags of 300 and she slides me 5.56

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Ditto. Or I’m not around and she grabs the wrong for herself. I’m also not above making the mistake myself, especially in a panic situation.

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