It’s been a long time in the making, but it’s done enough to get some feedback!
First, a little background…
In early 2012 I started thinking about a 300blk rifle for a pig gun. I figured I may as well go SBR and pretty much settled on a Noveske 9”. At that time, the factory SBR’s were really hard to find, so I bought a stripped Noveske lower with the intention of doing a form 1 on it.
By the time I got ready to start the process, Sandy Hook happened. My priorities shifted and the project was shelved for a while. Early this year I decided to revive the project. By then I saw several members here and on 300blk talk with under 9” barrels and started thinking shorter as well…
The barrel:
At first it was 8.2” Then 7.5”. Then I saw Ice Arm’s 6.75” and really started drooling. However, their less than stellar record pretty much excluded them from my selection process. I needed a barrel maker I could trust. I actually started a thread on this forum and 300blk looking for recommendations and a few notable makers came up.
I also figured that if I am going with a professional, I may as well go even shorter. I got it in my head that 6” would be neat based on my suppressor choice.
I contacted Lothar Walther first. They quoted me $400 for a barrel, but I had to deliver all the specs. They would not assemble, test or verify. I really did not want to take a chance on doing this build myself.
I then got in touch with Bill Pace at Houston Armory. If you guys recall, they built an integral 300blk AR a while ago and posted them on this forum. I spoke to Bill and we worked out a plan to develop the barrel and test it out with my setup. I ended up going with a stainless 1/8 twist spiral-fluted ultra-match barrel. Bill has a long history with short 300blk barrels.
I am very pleased with the results! Bill assembled everything and tuned it with the suppressor and my intended loads. The guy knows his short barrels!
The suppressor:
Part of reason I went with a 6” barrel was the suppressor I decided to go with. Maximum suppression was not the goal of this build. Absolute compactness was. I bought a Thunder Beast Arms 30PSS suppressor. Currently the shortest, lightest 300blk can available. So I figured, 5” can with a 6” barrel would give me a rifle that was easy to handle in Florida’s brush.
The receivers:
I kept staring at the Noveske lower I had and decided it wasn’t right for this build. I was headed into “stupid build” territory and happened to see a set of new Umbrella Corp upper and lower receivers for sale locally. Being a huge fan of the games and movies, this was an awesome find. Unfortunately the guy decided to color fill everything on both the receivers, but the trade was good. My Noveske for both the lower and upper.
The hand guard:
I needed something to cover all of this. I am not a fan of integral suppressors, but a 5” hand guard just wasn’t really an option. I started looking at factory offerings, but couldn’t really find the combination of length and simplicity I was looking for. I did not want quad rail or really any rail at all, just something on the bottom. At first I was going to by a factory rail and have it cut down to my oddball length. By then, the cost for buying the rail, cutting it and refinishing was approaching the cost of a custom rail. So I got in touch with Mike Carpenter at Unique AR’s. The idea morphed from a simple idea into an Umbrella Corp themed rail. Mike and I went back and forth on a few designs and tons of revisions to arrive at the final product. The rail is 10.5” long, exactly long enough for a perfectly flush look and I can still access the adjustable gas block with a stubby hex key through the slats. Since this rifle will never be fired unsuppressed, removing the can isn’t really an issue, but if I need to I just use a strap wrench.
The stock:
I had an NEA CSS stock I picked up a while ago and really wasn’t intent on using it for this build. However, as it kept progressing it started looking better and better, so I decided to go with it. I wouldn’t want to go through a case of ammo using this stock, but for light use it’s OK.
The “look”:
I don’t have any vanity guns. Everything I own serves a purpose and to be honest, I don’t treat my stuff as well as I should. Engraving or anything like that really isn’t something I care about. The whole thing really just started with a desire to mark my upper and magazines with “300blk” so I clearly tell it was not a 5.56 AR. I could not find a port door cover with just “300blk” and had a hard time with magazine identification. Since I needed to engrave the lower for the form 1, I got in touch with Jeff Morris at LEO Armory. By then I was pretty much all-in, so I sent him a box of stuff and he engraved a few Magpul magazines, a dust port cover, charging handle, NEA bolt carrier, stock base and an Umbrella Corp grip. Totally over the top at this point!
The guts:
Umbrella Corp lower parts kit
SLR Rifle Works adjustable gas block and gas tube
Primary Arms microdot on a Fortis mount
Streamlight TLR-1 light
AR-15 gas vent in place of forward assist
BCM charging handle
The results:
So far I have run 200 rounds of 220gr Remington and 120 187gr Gem-Tech through it. I managed 2.0” groups at 25 yards (the limit of the crappy indoor range I went to) shooting off-hand without the hand guard using a Primary Arms RDS.
Suppression levels are OK, but not as quiet as the SureFire SOCOM 762 I compared it to. It was definitely quieter with the SureFire, but at a length and weight cost. The goal of this build was short and light. I was not expecting amazing suppression, but the fact that it is hearing safe indoors with just the 5” can is awesome!
The gas system is awesome… much nicer than any of my 5.56 guns. There was a bit of unburnt powder as would be expected from such a short setup, but no noticeable blowback.
In the 320 rounds I fired in that session, I did not have one single unintentional malfunction. I purposely closed off the gas to disable the cycling a couple of times, but every single round fired, ejected and cycled without issue.
As for heat… well, anywhere my support hand grips is either gas block or can, so yeah, it gets hot! I may add an angled grip of some sort, but it was OK to handle with gloves. In the field, shooting only a few rounds won’t be an issue. 300 rounds in one session is unlikely to happen very often with this gun anyways.
One issue I was concerned about was the can loosening and not being able to easily tighten it with the hand guard in place. One of the benefits of a custom barrel is the threads being cut to match the suppressor. The lockup on this can is tighter than any other screw-on can I own, but that’s not to say it will be like that forever. In my first outing, the can didn’t budge at all. It’s not so much of an issue now because the hand guard covers it from knocks and I don’t shoot 300 rounds when hunting, but in the future I may fashion a retaining pin or something similar.
I don’t have an accurate enough scale but it weighs about 6.5lb with the sight, light and unloaded magazine. The NEA stock is pretty rear-heavy, so it balances it out very nicely.
What’s left?
I want to remove the color fill and cerakote the whole thing in either simple black or sniper gray, but that will have to wait until I bag a few hogs first!
I may swap out the adjustable gas block for a standard one; it just doesn’t seem necessary seeing as how I will really only run it with these two loads.
I may also get rid of the trigger guard. I don’t know what I was thinking on that one…
So anyways, this is my first totally custom build. I went a little crazy, but what the hell… Please let me know what you think!
