SilencerCo SCO15 Lower Receiver
Courtesy SilencerCo

With demand at an all-time high, SilencerCo chose the perfect moment to launch its new AR-15 stripped lower receiver, the SCO15. Silencer Shop got their hands on a couple of samples (if you’re interested in snagging one once they’re in stock, join the mailing list here) and I was lucky enough to borrow one and build it out for testing.

SilencerCo SCO15 Lower Receiver
Jeremy S. for TTAG

Machined from billet 7075 aluminum and Type III Hardcoat anodized black, the SCO15 lower receiver has a few unique tricks up its sleeves.

SilencerCo SCO15 Lower Receiver
Jeremy S. for TTAG

Typically a stripped lower means no parts whatsoever are included, but in the case of the SCO15, it comes with its own completely ambidextrous bolt catch. Passing through the top of the receiver and out the right side, this bolt catch allows the shooter to manually lock the bolt back as well as release the bolt from lock very easily with a single finger.

SilencerCo SCO15 Lower Receiver
Jeremy S. for TTAG

For a right-handed shooter, the placement and shape of the right-side lever is ideal for operation with the trigger finger. Push up on the bottom of the lever to lock the bolt back, push down on the top to release the bolt.

SilencerCo SCO15 Lower Receiver
Jeremy S. for TTAG

On the left side of the receiver, the bolt catch design is faithful to mil-spec. It ships uninstalled, so you’ll need a standard lower parts kit spring, detent, and roll pin to hold it in place.

SilencerCo SCO15 Lower Receiver
Jeremy S. for TTAG

One final note of interest: the bolt catch is “3D-printed” (laser sintered) from 17-4 stainless steel.

SilencerCo SCO15 Lower Receiver
Jeremy S. for TTAG

Starting with a big block of aluminum rather than a forging that’s nearly in final form allowed SilencerCo to machine some unique features into the SCO15.

One standout is ambidextrous, anti-rotation QD sling cups integrated into the rear of the receiver. Very cool.

Also seen in the photo above, though certainly not limited to billet lowers, is a unique safety selector “Fire” marking that works with both 45-degree and 90-degree throw safety levers (or any in-between).

SilencerCo SCO15 Lower Receiver
Jeremy S. for TTAG

The SCO15 features a large, integral trigger guard with a comfortable flare at the rear for the shooter’s middle finger support and a flared front that flows nicely into an enlarged magazine well funnel.

SilencerCo SCO15 Lower Receiver
Jeremy S. for TTAG

Above the trigger guard is a similarly-shaped flare that protects the magazine release from accidental activation. And, sure, it also looks cool as it flows from there up across the top of the magazine well where it houses the spring and detent for the pivot pin.

SilencerCo SCO15 Lower Receiver
Jeremy S. for TTAG

Up front, the shape of the flared magazine well and deeply chamfered receiver edges feel good in the hand for you weirdos who like to hold the receiver while shooting instead of, you know, the aptly-named handguard.

SilencerCo SCO15 Lower Receiver
Jeremy S. for TTAG

Of course, the purpose of a stripped lower is to turn it into a complete lower, and then turn that into a functional rifle or pistol. Under the bright lights of Silencer Shop’s studio, filming a video on how to assemble a stripped lower receiver, I built out the SCO15.

SilencerCo SCO15 Lower Receiver
Jeremy S. for TTAG

Robbing these components from Black Collar Arms, I installed an ERGO Enhanced Lower Parts Kit, an ELF-SE Trigger with straight shoe, and an ERGO Swift Grip. From my personal spare parts department I grabbed the awesome Lancer Systems Carbon Fiber Fixed Stock.

SilencerCo SCO15 Lower Receiver
Jeremy S. for TTAG

Assembly on the SCO15 was smooth and typical. The only unique aspect of assembling it is the takedown pin detent — it goes up through the bottom and is held in place by the pistol grip instead of inserting through the rear and being held in place by a receiver end plate.

Had I designed the SilencerCO SCO15 stripped lower receiver there’s really just one, minor change I would have made. Instead of a hammered-in, traditional roll pin / split pin for the bolt catch I would have gone with the more modern, easier-to-install shoulder screw system.

Not a huge deal, but I happened to struggle a little with this part of the assembly thanks to either a slightly oversized pin or an undersized pin hole, so between some light swearing and some heavy hammering I pined for that shoulder screw. Additionally, the rear QD cup made it harder to align a punch properly and drive that pin in, which didn’t help.

I’d definitely recommend using masking tape to protect the QD cup and the area around the bolt catch from assembly-induced finish damage.

SilencerCo SCO15 Lower Receiver
Jeremy S. for TTAG

I slapped on an Adams Arms upper and headed to the range.

SilencerCo SCO15 Lower Receiver
Jeremy S. for TTAG

No surprise here; everything ran great. The SCO15’s flared magazine well made mag changes easier, and the bolt catch functioned flawlessly from the right side. Easy to lock, easy to drop.

SilencerCo is machining the SCO15 in-house in their Utah facility, and the machining quality is great. I found no tool marks or mistakes anywhere; just smooth, clean aluminum. Likewise the hardcoat anodizing is a flawlessly consistent, deep black.

With an MSRP of $249, SilencerCo is targeting the premium end of the market. Of course, this is unquestionably a premium receiver with unique features like the ambidextrous bolt catch and integral QD cups, plus that SilencerCo logo that we aren’t used to seeing on a receiver. They’ve also launched it at a time when AR-15 parts demand is through the roof and inventory is low, so I’m positive they’ll sell every single one they’re able to make as quickly as they’re able to make them.

If an SCO15 is in your future, I’d recommend signing up on the Silencer Shop SCO15 page for in-stock notifications. My guess is they’ll be relatively hard to come by.

Specifications: SilencerCo SCO15 Billet AR-15 Lower Receiver

Caliber:  Multi
Materials:  7075-T6 aluminum receiver, 3D printed 17-4 bolt catch
Finish:  Type III Hardcoat Anodized
MSRP:  $249

Ratings (out of five stars):

Overall  * * * * 1/2
SilencerCo’s SCO15 is a great lower receiver with fantastic machining and consistent finish, plus some unique, functional feature enhancements. Sure, I’d tweak that bolt catch to use a shoulder screw instead of a roll pin, or possibly just ship the lower with the bolt catch already installed from the factory, but it’s otherwise a very well thought-out, really nice lower.


  1. $250 for a stripped lower!? In an already (sales boom aside) overly saturated AR-15 market!? There are ZERO polite words for what Silencerco can do with that. Stick to making some good cans, or maybe make something more worth the price your name demands because a lower is NOT it.

  2. Yeah, about five times the cost of a typical stripped lower. The little extra touches are not worth $200.

    I wish them well, perhaps some rich people will want the matching logo with their suppressor???

    • Make no mistake though this weapon aught to be banned. For the children. Also, anyone who protests it’s banning aught to be jailed as a domestic terrorist.

        • Yep. Too rich for my blood. I drove a stock Chevette for years with zero problems, and was quite happy.

          I can build a probably-not-as-posh AR for about $350. Or I did last time. Haven’t priced things since the start of the last panic.

  3. Don’t need billet when stronger forged quality receivers are less than 1/2 the cost, can buy a complete forged receiver with trigger group, stock, buffer and buffer tube assembled for the same price from Palmetto. Thanks but no thanks.

  4. Good looking, not worth the cost. I don’t know anyone willing to pay that price for a stripped lower, ever.

    • Name brand boyos will chase these down like crazy, but if I want a billet lower I’m going Aero Precision for half the cost, if you stalk their site you’ll get one eventually.

        • I’ve got one way to find out…

          I apologize to everyone reading and the TTAG staff for what is about to occur…

          I will utter the following phrase, and it shall summon a troll demon from the depths of the dark web. May God have mercy on this thread.

          I hereby evoke the storm of doom, I say:


        • “PG…PG…

          Why does that sound familiar?”

          Ah, you 2?

          *snicker*… 😉

      • I hit that “notify when in stock” button for every single lower on aero’s website a long time ago… not one notification sent to date. Luckily, I can shop locally or just go to somewhere like PSA. Tons of options online, but I already have 2 builds, I am good for a while. The focus right now should be ammo for anyone who already owns a rifle, even just one rifle. You will see why soon, actually, you already are, but this is just the tip of the iceberg.

  5. Nice lower, no doubt high quality, unlike PSA garbage, but, For $250, better come with a voucher for 250 rds of M855.

  6. The safety detent is always captured or retained by the grip, is this being confused for the takedown detent? Assuming that the QD is in the way.

  7. High priced lowers have been around forever, and maybe I don’t run in the right circles, but I have yet to hear of a low priced lower failing. Some have issues mating with uppers and the like, but that is an avoidable issue. So what is all that extra money for? With tax, transfer fee ($25) and DROS, this sucker will cost over $300, which not so very long ago was fairly close to the cost of a complete rifle. I would speculate that this lower is a bit lighter weight, but the cost-benefit ratio of a few ounces saved is not enough to justify the price. (The last lower I bought was a Spikes for $115. And there are plenty half that cost.)

    • Yeah it’s kinda like how Toyota Camrys don’t fail, but people still pay more money — sometimes WAY more money — to have a fancier car that looks better and is more feature rich or, sometimes, just cooler.

  8. Not looking for a lower but you guy’s complaining about the price need to peruse the prices of run of mill AR-s on Gunbroker. It’s INSANE! I wish I had bought that AR left from my favorite pawnshop. He had 4 new’used’ S&W Sports. I got one for 400OTD…and ton’s of cheap ammo.

  9. I notice Jeremy is still name dropping Black Collar like he’s a disinterested 3rd party, and not using TTAG for free advertising of his own company. He following in the footsteps of esteemed gun writers, such as Ayoob.

  10. Don’t use a hammer on pins. Press them in. Taper the ends then use a Vice Grip or Channel Locks wrapped in tape to press it in. Put a little tape near the area on the lower and you will preserve the finish much better.
    If the holes/pins are the wrong size then use a different part or properly drill it out. You should not be going all Bam Bam on it.

    • “If the holes/pins are the wrong size then use a different part or properly drill it out.”
      Naah, you just need bigger hammer!

      I use drop in triggers in my builds with anti walk pins. They come with a little pointy attachment that screws on one side of the pin and make the installation with bare hands easy.

  11. Whats up with the near 90 degree pistol grips ive been seeing lately? Is there any advantage or is it just a preference on the feel?

  12. Tramp stamp of a logo on a vanilla lower. No thanks hard pass stick to making garbage cans silencercompany 😂😭

  13. Of course, if you have SilencerCo etched into the lower, you will need to buy a suppressor from SilencerCo to go with it.

    If you give a mouse a cookie…


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