While visiting friends in Portland, Oregon, I realized that Portlandia isn’t a very creative show. It’s actually more observational; practically a documentary. Seriously, how does a button store or a terrarium store or three piano stores within a half mile of my friend’s place survive? Maybe they’re just trustafarians selling pianos ironically? Anyway…silencers. Delta P Design makes the BREVIS II family of compact rifle suppressors, which piqued my interest at SHOT Show 2015. Not only are they really freaking compact and mind-bogglingly lightweight, but they’re the first 3D printed suppressors on the market. That makes them cool. But to find out if they actually work, I escaped Portland, drove a half hour south, and met up with the guys from Delta P for a range day. . .
“3D Printed” can refer to a handful of types of additive manufacturing processes, and Delta P isn’t using the MakerBot-squirting-melted-polymer method we typically think of. These suppressors are manufactured via a DMLS — direct metal laser sintering — process. In general, this means a very thin layer of very fine metal powder is deposited onto the work surface, and then a high-powered laser fully fuses — sinters — only specific areas of that layer to the previous layer. One super thin slice at a time, your object coalesces in the full meaning of the word, as the final product is not separate layers “glued” together but, truly, one homogeneous, monolithic unit.
All sorts of advantages can be had through DMLS as compared to machining, casting, and other manufacturing methods, and Delta P is putting many of these to good use. In fact, they made it quite clear to me that they came to DMLS as the only means of turning their unadulterated silencer designs into reality. Creating a 3D Printed silencer was not their intention, and the engineers who own and run the company actually kept the manufacturing method entirely under wraps until now in the fear that it might be perceived as a sales gimmick. So, again, they stressed that Delta P wasn’t started to see if 3D Printed silencers would work. Rather, they engineered what they thought would be the best silencer design possible and then realized DMLS was the only real way to actually manufacture it.
“Compact” doesn’t adequately describe just how small these things are. In the photo above, that’s a raw finish .223/5.56 BREVIS II sitting next to a SureFire X300. The can is like an 1/8th of an inch longer. On paper, the BREVIS II clocks in at a stubby 3.7″ long in 5.56 flavor and 5.5″ long in the larger caliber variants.
Oh, and the 5.56 Ultra only weighs 6.6 oz. That’s insane! But more on this later, as I have to geek out on the size and design for a while first…
When I saw them at SHOT Show I thought the size was obviously super cool — adding only ~twice the length of an A2 Birdcage, a BREVIS II-equipped patrol rifle will still fit in standard cruiser mounts and is sure handy for vehicular ingress/egress and working in small, interior spaces — but figured there’s no way they’re anywhere near hearing safe! Of course, I managed to forget that the radius is squared when calculating the volume of a cylinder. Thanks to the BREVIS’ larger diameter, the 5.56 model has the same interior volume as if it were a 6.5″-long, standard-diameter silencer.
Internal volume, really, is the name of the game when it comes to silencer efficacy, but obviously as size goes up so does weight. As a tube’s pressure-holding strength decreases as diameter increases — given the same tube wall thickness — we find most rifle silencers stick to a fairly standard diameter. To increase interior volume they get longer, not wider, mostly for this reason. Additionally, with standard manufacturing processes, a longer can means more baffles.
DMLS offered the ability to create interior features that would be impossible through traditional means or, at least, effectively impossible due to the complication and outrageous costs required. It also wouldn’t be anywhere near as strong as Delta P’s DMLS design, which results in a one-piece product. No welds, no threaded-in parts, etc. As an example, not only is the mount completely integral rather than a welded-on or screwed-in piece like with every other can, but it’s the very same piece of metal as both the body and the internals and flows directly into some of the internal support structures. Forces on every part of the silencer can be distributed and shared in ways that are impossible otherwise.
This is one of the reasons the BREVIS line can employ a wide diameter while, in 5.56, still being rated for use on barrel lengths as short as 7″. I don’t recall if there are restrictions on the .30 cal can, other than it’s officially rated for at least .300 RUM and is a-okay for full-auto .308 on a 16″ barrel.
The one unique internal feature that I can share — the one I know of and one of the ways they’re taking advantage of 3D printing — is that the blast/expansion chamber is significantly larger than you’d expect. Larger than the norm, in fact, which means a faster pressure drop as gasses exit the muzzle, which means a bit less blowback through the firearm’s action than the norm. Basically, imagine a normal-diameter baffle stack tube inside of the larger-diameter BREVIS body, and “float” the nicely-sculpted blast baffle in space except for some supports that connect it to the body. Now your blast chamber extends the entire length of the suppressor. Then the inner core is basically normal in diameter. Putting my imagination and MS Paint skills to work (and leaving out support structures since they would look like gas-stopping walls), in cross section it’s something vaguely like this:
To be clear, I created the amazing drawing above based on my own assumptions. It’s certainly incorrect, as I don’t know what’s actually inside of the core part, what’s inside of the blast chamber part, or whether gas can exchange between the two anywhere other than via the bore. It also grossly simplifies the complex, sculpted, interconnected internals that only 3D printing could accomplish. But, looking down into the can through the mount, it’s apparent how the blast baffle allows gas to go around it and down along the silencer’s walls to create a huge blast chamber volume.
So the small size is awesome, of course, and the information gleaned above was meant to convince me that a 5.56 BREVIS II is physically capable of being just as quiet as a longer-but-skinnier market standard like the AAC M4-2000. But one of the other advantages of DMLS manufacture is the unencumbered ability to put material where it’s needed and only where it’s needed.
This, combined with the monolithic nature of the BREVIS II, is why it can be so incredibly lightweight yet even stronger than the norm. Whether it’s the standard model, which is 100% Inconel, or the Ultra model, in which key parts like the blast baffle are Inconel but most of it is titanium (but it’s all one, solid piece of metal regardless), these silencers are way lighter than their competition. The numbers break down like this:
- BREVIS II 5.56: 11.5 oz
- BREVIS II ULTRA 5.56: 6.6 oz
- BREVIS II 7.62: 16 oz
- BREVIS II ULTRA 7.62: under 10 oz
There are also cans for 6.5mm and 8.6mm (think .338 Lapua Mag) calibers, and, like the 5.56 and 7.62 flavors, they weigh from as little as 1/4 up to about 1/2 of what their competition weighs. As an amusing exercise, Delta P’s .338 Lapua can weighs 10 ounces. Go forth and Google, and compare that to its peers.
On The Range
Small, light, and unique. Check. But they ain’t cheap. You may go down by [at least] half on the weight but you’re likely to go up by half on the price. So they have to perform, and perform well.
They definitely do that on strength. The 5.56 and 7.62 silencers are full-auto rated to shorter barrel lengths than the competition. During our time on the range, we shot the BREVIS II 5.56 on a 6″ barrel (officially, it’s rated for 7″+) and it shrugged that right off, of course.
While it can’t quite quiet things down to under the OSHA-suggested 140 dB max level on that short of a barrel, it does get rid of all of the brain-rattling concussion and turns the beach ball-sized fireball into a bad memory. I’ll actually be borrowing one for the next 5.56 flash hiding test because of how extremely impressive it is in this role. In the meantime, here’s a quick video that shows 5.56 through a 6″ barrel with and without the BREVIS II attached, and shows both a well-known competitor’s .30 cal can and the BREVIS II 7.62 on either a 16″ or 18″ (I don’t recall which) barrel shooting .308 Win.
As for the BREVIS II’s volume levels on various barrel lengths for both 5.56 and 7.62:
- 5.56 (Federal M855) on 16″ bbl: 134-135 dB
- 5.56 (Federal M855) on 10.3″ bbl: 138-139 dB
- 7.62×51 (M80 ball) on a 24″ bbl: 135-136 dB
- 7.62×51 (M80 ball) on a 20″ bbl: 138 dB
Compared to their peers they’re solid performers but they aren’t breaking records. Well, other than what I think are length, weight, and sound suppression per inch/ounce records. Of course, dB meter readings don’t correlate exactly with the human ear’s perception of loudness. Two suppressors metering at the exact same sound pressure level can actually sound quite different in person — one noticeably “louder” than the other — due to tone, peak duration, and other factors.
From what I’ve experienced personally as well as heard from others, in general a deeper tone will seem quieter. For example, 135 dB at a higher frequency is more likely to cause discomfort than 135 dB at a lower frequency, and will generally be perceived as being louder. Some suppressors have positive reputations for producing a “low tone.” When there are enough of Delta P’s BREVIS IIs out there to build up a reputation (note that they are a generational improvement over the original BREVIS models), they’ll be known for this sort of complimentary tone. The interior volume, design of the large blast chamber, and solidity of the monolithic structure combine to product a solid, lower-pitched tone.
These are supposed to be lifetime suppressors. They can be pinned and welded onto a barrel to bring it up to a certain length (I’d like to use the 7.62 Ultra on a .300 BLK upper, permanently attaching it to bring the effective barrel length just to 16″), and barrels can be cleaned in the normal fashion with the can on the end. In fact, the whole idea is to basically treat a BREVIS II like any other muzzle device — flash hider, muzzle brake, etc — and consider it a more or less permanent part of the barrel, simply leaving it in place.
Leading and carbon buildup is not much of a problem with centerfire rifle rounds, but if desired these suppressors can be cleaned in an ultrasonic tank, with brake/carb cleaner, via “the dip” (soaking in a 50/50 white vinegar and hydrogen peroxide solution to dissolve leading — just note lead acetate safety precautions), etc. Basically, don’t get hung up on the “3D printed” thing, because there are no limitations on these cans that wouldn’t also apply to one made from a solid billet of Inconel or titanium.
I was able to inspect a BREVIS II 5.56 with, according to Delta P, coming up on 10,000 rounds through it — much of that on a stubby barrel, including under full-auto fire — and the only sign of wear or degradation was minor pitting around the bore hole of the blast baffle. I don’t think it was enough to change the effective hole diameter, but the once-crisp, clean edge was now a bit fuzzy. Use was evident from heat-induced coloration on the exterior, burned on carbon staining on the interior, etc, so the thing was clearly run hard.
The Ultra (Ti) versions are just as tough as the 100% Inconel standard versions outside of sustained, full-auto use. They have the advantage of being lighter, but the disadvantage of being more expensive.
Unfortunately, due to the nature of NFA items I can’t do a full review on a BREVIS II without buying one, paying the $200 transfer, waiting the ~6-9 months, etc. If I decide to buy a dedicated 5.56 can at some point I probably will be calling up Detla P. For now, though, this is just an “initial impressions,” range review sort of a post and it’s a bit limited in that as well, since shooting at a public range mandated wearing ear pro the entire time and meant shooting under a tin roof and near a concrete wall as seen in the video.
What I can say for sure is that the BREVIS II 7.62 on an AR-10 sounded just as quiet as a significantly larger, heavier can from a well-known manufacturer (if it were an actor, it would be an A-list celeb), that all of the BREVIS II line produces a nice, low tone, and that they appear to be rock solid.
Oh, and when you pick up the 6.6 oz 5.56 Ultra you giggle and think it’s some sort of joke. Cover the hole on either end and the darn thing will float. It’s basically impossible to feel a difference in rifle balance or handling between a bare muzzle and an Ultra-equipped muzzle. That’s sort of awesome.
Specifications (Delta P Design BREVIS II Suppressors):
5.56 Weight: 11.5 oz standard, 6.6 oz Ultra
5.56 Length: 3.7″
5.56 MSRP: $1,386 standard, $1,491 Ultra
7.62 Weight: 16 oz standard, under 10 oz Ultra
7.62 Length: 5.5″
7.62 MSRP: $1,764 standard, $1,895 Ultra
See Delta P website for stats and info on 6.5 and 8.6 suppressors