Dirty Bird MCF-A Ambidextrous Lower Receiver
Introducing the Dirty Bird Industries Multi-Cal Forged Ambidextrous (MCF-A) Lower Receiver. When evaluating a lower, first priority is making sure the basics are done right.
Start with Quality Forgings
All MCF-A lowers are machined from top-tier 7075 Aluminum Forgings from Cerro Fabricated Products. It is a common misconception that all forgings are created equal. Cerro Fabricated Products has been a leader in precision forging, machining, heat treating and more since 1915.
Meticulous Machining
We wanted perfection, so we teamed up with the folks at MVB Industries. MVB, best known for their innovative ARC-X PDW Stock, is one of the industries’ best kept secrets. And while we’d love to keep them all for ourselves, we can’t talk about the quality of this lower without giving huge props to their team. Lots of companies are known for their creative vision, others are known for their unwavering attention to detail. MVB does both, and they do it very, very well.
A Quality-Control Centered Process
You’ll notice that in addition to ATF issued serial numbers, all of the lowers feature a unique identifier machined near the pistol grip interface. This is for tracking each individual unit throughout the production process. This added step allows QC staff to trace any potential quality issues back to an exact machine and a given batch, no matter how long it has been since that unit was produced.
Practical Improvements
It is one thing to add features to a battle proven design that is over 60 years old. There are some pretty crazy lowers out there, but are they practical? Do they sacrifice reliability? Do they make the lower more difficult to service or upgrade?
Ambidextrous Bolt Catch / Release
The Dirty Bird MCF-A Lower Receiver uses MVB’s patented mechanism that implements an Ambidextrous Bolt Catch / Release with elegance, rather than complexity.
- The mechanism both releases and actuates the bolt catch automatically. If the bolt is already in battery, hitting the lever will raise the bolt catch, enabling you to lock the bolt back. If the bolt is locked-back, hitting the lever will release the bolt. Simple.
- The mechanism is non-interfering, meaning that if the Ambi bolt lever is damaged during hard-use or movement is blocked by debris, the standard bolt catch / release paddle still functions flawlessly.
- The mechanism consists of only 4 proprietary components, all of which are machined from Billet S7 Tool Steel and QPQ Nitrided which means pretty much anything on the lower would break before they do.
- Utilizes zero hex screws. Instead, the Ambi Bolt Catch lever is installed with a standard bolt-catch roll pin. This simplifies things and gives the unit a higher level of serviceability.
Made in the USA
Backed by the Dirty Bird Limited Lifetime Warranty
*Limited compatibility with anti-walk / anti-rotation pins. We can confirm compatibility with Dirty Bird Brand Anti-Walk pins.
*Black color is type 3 hard anodized per mil-spec. Other colors will be Cerakote.
| Weight | 0.0000 oz |
|---|---|
| Color | Black, FDE, Midnight Bronze, OD Green, Sniper Grey |
Compliance
NFA (National Firearms Act) compliance is crucial for legal ownership and transfer of regulated firearms and accessories like short-barreled rifles, suppressors, and certain types of ammunition, ensuring adherence to federal regulations to avoid legal penalties and ensure responsible firearm ownership.
Customer Reviews
- Reviews
- Questions
US
It passed SOTAR save for one minor issue
Took this to SOTAR for his class and everything passed with flying colors save for the buffer tube threads which were a class 1 (lowest grade), but with FCD buffer tube, class 2, and A5 barrel nut, class 3 with some vibratite we got it to around a 2 - 2.5 class. The magwell had no issues with military gauges either. The ambi controls are unique and I like them over other offerings like ADM, Radian, etc. The right side bolt catch / release does take a little effort to use, but if fine otherwise.
USAnti-rattle pin included
There is little mention of the spring loaded pin near the buffer tube that applies pressure to the upper receiver, effectively removing the chatter between the upper and lower receiver. The Dirty Bird lower is the only receiver I've seen that includes it in their product. Bravo! This makes the Dirty Bird Lower Receiver one of the nicest receivers on the market.
USDirty Bird Ambi Lower
Very impressed with this lower! I have tried most of the ambi lowers (Radian, LMT, Aero, American Defense and a few others) While a couple of the name brand lowers might be a little more robust. I feel like the Dirty Bird is the most intuitive option. The bolt catch/release is the same mechanical action. Some of the other brands use a different lever/button for the bolt catch and/or release or are not truly ambi with NO right-side bolt catch, buy with confidence!
USHidden gem
As someone who’s either owned or tried all the mainstream ambi lowers (adac, adm, LMT, LWRC, etc) this is not only the most effective but also maintains the compatibility and strength of a regular forged lower.
USIf the only bird you know about is a duck... you're missing out!
Not only did I get the lower, picked up the upper, bcg, handguard, trigger... this was a great build and the tolerances are fantastic! I've built over 30 and this went together as easily as noveske and solgw with no additional machining or lapping required.
