Silencer Review: YHM R9 Fully Welded 9mm Suppressor

When a straightforward, durable, good looking suppressor at an aggressive price comes along, it’s sure to catch my interest. Checking every one of those boxes, YHM’s new R9 jumped right to the top of my to-test list and Silencer Shop was there to put a loaner unit in my hands. If you expect mediocre performance from a $449 MSRP suppressor, guess again. The YHM R9 is fantastic.

In the box you’ll find the R9, a 1/2×28 fixed mount, and a spanner wrench. The wrench indexes into tool slots located between some of the .223-shaped reliefs machined into the base of the silencer.

Wrench flats on the fixed mount provide a simple, standard tool interface for tightening or removing the mount from the suppressor and/or the host firearm.

The R9’s base uses what has become the industry standard 1-3/8×24 thread pattern, opening up an entire ecosystem of mount options from many different manufacturers including all sorts of QD systems, 3-lugs, boosters, fixed mounts, and more.

That said, take note of the distance between the base of the can and the front face of the first baffle, as some QD muzzle brake systems and boosters may be too long to fit into the R9. I’ll go ahead and state that most will work, but there are definitely some that will not. If you’re unsure, contact the pros at Silencer Shop or, of course, Yankee Hill Machine and they’ll get you sorted out.

A tubeless design, the R9 is manufactured entirely of 17-4 PH Stainless Steel with eight fully-welded baffles. No sir, it is not modular (other than the mounting system) or user serviceable. What it is is extremely durable as well as quite lightweight at just 10.7 ounces.

Uh oh, you’ve shot 2,500 rounds of 9mm and you’re feeling like it’s time to clean out that pistol ammo gunk from the inside? Shoot some 5.56 through it. Problem solved.

As a fully-welded 17-4 can, the R9 is rated for quite a lot of abuse above and beyond pistol calibers. In fact, with a 16-inch or longer barrel you’re good to go on .223 Remington/5.56 NATO, .308 Winchester, 350 Legend, 6.5 Grendel, and 7.62×39. With an 8-inch or longer barrel, 300 Blackout is in play.

Considering the YHM R9 is only 5.2 inches long, I had some reservations as to just how quiet — or loud — it might be. Heck, it’s barely larger than Roger, my pet backyard banana spider who isn’t much of a conversationalist but does a fine job proofreading my articles and staring at me with all of his cold, unblinking eyes while I write reviews on the patio with a cigar and a strange twitch in my neck as he gets uncomfortably close to my shoulder from the high ground above and behind me, which isn’t at all creepy or disconcerting and is just fine.

Out on the shooting range and well-armed against banana spiders, I first shot the R9 on an AR-15 style pistol caliber carbine chambered in 9mm with a 16-inch barrel. As a “subgun can,” the R9’s design is predominately focused on this sort of use including on 9mm SBRs and full-auto subguns.

And the R9 was pleasantly quiet. Impressively quiet, in fact, given its compact size. The vast majority of the sound experienced by me, the shooter, was due to the ejection port noise and general action noise of the PCC (one reason I’m not a big fan of AR-style direct blowback nine-millimeters). Impacts of the 147 grain subsonic Armscor ammo were clearly heard as the bullets thudded into the dirt berm backstop.

Swapping the 1/2×28 fixed mount for a booster unit, it was time to test the R9 a little harder by asking it to suppress the same ammo on an extremely short barrel.

Again, the little can was quieter than I had anticipated. It easily holds its own with longer suppressors designed exclusively for pistol use. In fact, YHM rates it at 123 dB on a 4.5-inch barrel, which frankly seems awfully optimistic but if accurate puts it in the upper echelon for 9×19 sound suppression.

The only negative to running the YHM R9 on a pistol — or at least on my P365 — was a bit more debris blowback than average compared to typical pistol suppressors. Not enough to be distracting or uncomfortable, but I could feel a few more flecks hitting me in the face than I’m used to.

300 Blackout, though, amirite? Here’s a great photo that shows off the YHM R9 on my 300 BLK SBR with an 8.3-inch Ballistic Advantage barrel inside that Lancer Systems carbon fiber handguard.

Well, okay, “shows off” may not be accurate. Can you see it now? The R9’s 1.562-inch outside diameter fits absolutely perfectly inside the handguard, and its length was a happy bit of luck.

Now if that isn’t a sweet look, I don’t know what is. Even the “knurling” detail around the top of the R9 happens to look like it was designed to go with the similar notches at the business end of the Lancer handguard. Heck of a combo.

As you can see and clearly hear in the video, first round pop on this setup was pronounced. When I fired that first shot I expected it to simply be the volume level of this suppressor on this setup, but once again the R9 surprised me with its exceptional performance. Subsequent shots were quiet. Very quiet.

Thanks to the much longer delay in this direct gas impingement action compared to the straight blowback 9mm action plus, if I may say so myself, the impeccable gas system and buffer tuning I’ve done on this gun, it was hands-down quieter at the shooter’s right ear than the 9mm PCC. It was far quieter than I expected considering the short length and generous bore of the YHM R9 for 300 BLK use. Yet again I think it would hold its own against many of the mid- to small-ish, dedicated .30 cal cans on the market.

Looking at YHM’s published numbers, though, it isn’t quite enough suppressor to tame .308 to OSHA-approved hearing safe levels of sub-140 dB (YHM states 142 dB). Without a doubt it was well under that threshold with subsonic 300 Blackout, though, and I’d assume the same for subsonic 350 Legend and I’m sure for supersonic flavors of those cartridges and others given a certain minimum barrel length.

As I wrapped up testing for the day I was nothing short of extremely impressed with the YHM R9. It’s an awesome little subgun can at a fair price, and it’s a top performer. Combined with the 1.375×24 mount system and a fully-welded 17-4 PH SS construction, it’s ready to go on all sorts of different firearms in all sorts of configurations in many pistol and rifle calibers and with mounts of every variety.

That’s a lot of utility the R9 helps squeeze out of that $200 tax stamp. For all these reasons and more, the YHM R9 has found itself high up on my recommended list.

Specifications: Yankee Hill Machine R9

Caliber:  9mm (but rated for many calibers from .17 HMR to .308)
Diameter:  1.562 inches
Length:  5.2 inches
Weight:  10.7 oz.
Mount Type:  1.375×24 universal mounting threads. Comes with 1/2×28 fixed mount.
Materials:  17-4 PH stainless steel
Finish:  matte black high temp Cerakote
MSRP: $449 (find it for less at Silencer Shop)

Ratings (out of five stars):

Utility  * * * *
With the “universal” mount system and durable construction, the R9 can be used on a wide range of calibers and firearm types and with mount styles from multiple companies.

Form Factor  * * * * 
Compact, light weight, and good looking.

Suppression  * * * * *
Very impressive for its short length or, heck, just in general.

Overall  * * * * *
Given its capabilities and performance at its price point, the YHM R9 is a five-star suppressor.