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.300 Blackout subsonic ammo prices

Suppressor-optimized loads under 1,050 fps. The reason most people buy a .300 Blackout.

Price range$0.55—$1.00/rd
Search .300 BLK Subsonic
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IronScout provides observed price and availability data for .300 Blackout ammo prices .300 Blackout subsonic ammo prices ammunition across tracked online retailers. Data reflects historical price observations and does not include purchase recommendations.

Observed 30-Day Price Range (Per Round): median: 1.500, lowest: 0.478, highest: 8.500, sample size: 1877.

Prices last updated March 28, 2026 · 122 listings tracked across 6 retailers

.300 BLK subsonic options

Product LineGrainBulletCountTypical CPR
Sellier & Bellot 300 BLK Sub200grFMJ20$0.55—0.75
Magtech 300 BLK Sub200grFMJ50$0.55—0.75
Hornady Black Sub-X190grSub-X20—200$0.60—0.90
Sig Sauer 300 BLK220grOTM20$0.70—1.00
Federal American Eagle Sub220grOTM20$0.65—0.85

What to know about subsonic .300 BLK

Subsonic .300 Blackout — loaded to velocities below approximately 1,050 fps — is purpose-built for suppressed shooting. When paired with a quality suppressor, subsonic .300 BLK produces a hearing-safe report with dramatically reduced concussion compared to supersonic loads. This is the primary use case that drives .300 BLK adoption.

FMJ vs. expanding subsonic

The critical distinction in subsonic .300 BLK is between FMJ plinking loads and expanding defense loads. Standard hollow point bullets are designed to expand at velocities above 1,200 fps — at subsonic speeds (~1,000 fps), they behave like FMJ and pass straight through without expanding. This makes bullet selection extremely important for anyone using subsonic .300 BLK for home defense.

Hornady Sub-X is the standout expanding subsonic load. Its patented flex-tip design initiates expansion at subsonic velocity, something conventional JHP cannot reliably do. Lehigh Defense Controlled Chaos and Maximum Expansion bullets also offer subsonic expansion through non-traditional engineering (fragmenting or hydraulic designs).

For range and suppressor fun, FMJ subsonic loads from S&B and Magtech at $0.55—0.75/rd are the most economical option. Save the more expensive expanding loads for your defense magazine.

Cycling reliability: Subsonic .300 BLK generates less gas than supersonic loads, which can cause cycling issues in some gas-operated semi-autos, particularly those with adjustable gas blocks set for supersonic ammo. If running a suppressed AR-15, ensure your gas system is tuned for subsonic or use a suppressor with back-pressure characteristics that aid cycling.

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