Rosco Manufacturing 10.5″ 300 Blackout Purebred Barrel (1/7 Twist)

Original price was: $200.00.Current price is: $157.06.

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SKU: PB-105-HB-300BLK-7-P

Product Description

Purebred 10.5″ 300 Blackout Barrel: This Rosco Purebred 10.5″ 300 Blackout Barrel was designed for SBR/ Pistol use in conjunction with suppressors. The 10.5” Rosco barrel was made to be a direct precision replacement for any MK 18 platforms that are currently in 5.56 NATO. The 10.5” barrel is also perfect for carbines which require a slightly longer rail in order to run PEQ-15’s, D-BAL (series), or any laser aiming devices comfortably. ALL NFA RULES APPLY!

Rosco Manufacturing’s “Purebred” series is a testament to precision and quality manufacturing. We took a step back to see how we could create a barrel line that would be a culmination of all the lessons learned through years of making barrels for several OEM’s. The result is a barrel that will produce results out of the box for any shooter that is looking to take their skills above and beyond. All of our Purebred barrels are made from scratch in our Rhode Island facility and start life as a blank piece of 416R stainless steel.

Aside from making our own barrel blanks, and barrel extensions, we also hold ourselves to the most stringent quality standards. This is the only way that we can make sure that we are producing a product that will perform time after time under the demanding of situations. We are setting out to re-define the rules and we plan on letting our work do the talking…


Barrel Length 10.5″
Barrel Weight 21.09 oz
Barrel Material 416 R
Barrel Caliber 300 BLK
Barrel Profile




Barrel Thread

5/8 x 24

Barrel Gas Block Size


Gas System Length

Barrel Crown

Step Crown

Barrel Finish

80 Grit Bead Blast

Barrel Extension Finish

Nickel Boron




Technical Information


.300 AAC Blackout

Barrel Twist


Thread Pitch

5/8 x 24



Firearm Compatibility

Catalog Location

California Prop 65 Warning

WARNING: This product can expose you to chemicals, which are known to the State of California to cause Cancer and Reproductive Harm. For more information visit