Alamo 15 Trigger
About this product
This is a complete AR-15 pattern rifle from Anderson Mfg., chambered in 300 AAC Blackout - a semi-automatic, one-round-per-trigger-pull rifle built on the standard AR-15 receiver platform. 300 Blackout was designed to run subsonic or supersonic loads through a standard AR bolt and magazine well with only a barrel and gas system change from 5.56, which is why it has become a popular chambering for suppressor use and short-barrel builds. Anderson Mfg. is known as a value-focused AR manufacturer, building receivers and complete rifles to mil-spec dimensions at a lower price point than boutique brands.
What is it used for?
300 Blackout AR-15s are popular for home defense, hog and deer hunting within the cartridge's effective range, and suppressed shooting, since the cartridge was purpose-built to stay subsonic with heavier bullets when a suppressor is used. It is also a common choice for short-barrel or pistol-length AR builds because 300 Blackout retains more of its performance out of a shorter barrel than 5.56 does. It is a rifle-class firearm requiring the same purchase process as any other long gun in California.
How does it compare to a 5.56 AR-15?
300 Blackout trades some flat-shooting range performance for more downrange energy at closer distances and much better performance out of short barrels or through a suppressor. A 5.56 AR-15 is generally cheaper to feed and has a flatter trajectory for longer-range shooting. If your use case is home defense or hunting at moderate range, especially suppressed, 300 Blackout is a reasonable choice; if you want the cheapest possible round count for target practice, 5.56 wins on cost per round.
What fits it?
Standard AR-15 magazines, optics mounts, and most AR-pattern accessories fit this rifle since it uses the mil-spec AR-15 receiver and upper/lower interface - see our AR-15 pistol grip for one drop-in upgrade option. Barrel and gas system parts are caliber-specific to 300 Blackout, so 5.56 barrels are not interchangeable without a barrel swap. Standard AR grips, stocks, and rail systems that fit any mil-spec lower will fit this rifle.
Does it work in California?
California treats semi-automatic centerfire rifles with detachable magazines under its assault weapons law, which generally requires either a fixed (non-detachable) magazine configuration or a featureless build without the regulated features like a pistol grip that protrudes conspicuously. Confirm the exact configuration of this specific rifle with us before ordering, since compliance depends on the built configuration, not just the receiver brand. Standard long-gun rules also apply: FFL transfer, DROS, and the 10-day waiting period - see our California gun laws page for the full picture.
Who is this not for?
If you want the absolute flattest trajectory and cheapest ammunition for high-volume target shooting, 5.56 is the more practical chambering. Anyone unfamiliar with California's assault weapons configuration rules should talk to us before ordering rather than assuming a standard AR-15 build is automatically compliant. This is also not a rifle for someone wanting an out-of-the-box lightweight build - value-tier AR-15s like Anderson's are typically standard-weight, not lightened.
Pros & cons
What works
- 300 Blackout runs well subsonic and suppressed
- Standard mil-spec AR-15 magazine and accessory compatibility
- Anderson Mfg. offers solid value in the AR-15 market
- Good performance retained out of shorter barrels
Trade-offs
- Costs more per round than 5.56
- Configuration must meet California's rifle compliance rules
- Not the flattest-shooting option for long-range target work
Key attributes
| Caliber | 300 AAC Blackout |
| Platform | AR-15 pattern |
| Manufacturer | Anderson Mfg. |
| Classification | Complete firearm - FFL transfer required |
Frequently asked questions
- Is this rifle fully automatic?
- No. It is a semi-automatic rifle, meaning it fires one round per trigger pull, the same as any standard AR-15.
- Can I shoot 5.56 through a 300 Blackout upper?
- No, 300 Blackout and 5.56 are different cartridges requiring different barrels; do not attempt to fire the wrong ammunition through this rifle.
- Does 300 Blackout work well suppressed?
- Yes, it was specifically designed to perform well with subsonic ammunition and a suppressor, which is one of the main reasons shooters choose the chambering.
- What's required to buy a rifle like this in California?
- A licensed FFL transfer, a completed DROS, the state's 10-day waiting period, and a valid Firearm Safety Certificate for first-time buyers, plus confirmation the specific build configuration meets California's rifle configuration rules.