Rock River Arms Completed Upper Receiver Mid-Length A4 .450 Bushmaster 16 Inch Barrel 1-24 Twist 5/8-32 Thread Free-Float Handguard Brake Black

Upper Rock River Arms UPC 842834124138 MPN 450B0461

Rock River Arms Completed Upper Receiver Mid-Length A4 .450 Bushmaster 16 Inch Barrel 1-24 Twist 5/8-32 Thread Free-Float Handguard Brake Black

$591.99

at Good 4 Guns · checked 34 minutes ago

Shipping calculated in cart

8 retailers · $631.35 to $751.99 shipped

This listing: Optics Planet $665.99

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Shipping estimate for one item to the lower 48 from the retailer's published policy or feed; the retailer's cart is final.

Price history

Lowest price across retailers each day.

Lowest seen: $591.99
Typical price: $619.40
Tracked since: Apr 10, 2026

Today's best price matches the 214-day low and is 4% below typical.