The Sanders Armory 20″ Match Grade 6.5 Grendel (Type II) 416R Stainless Steel Hand Lapped barrel with 1:7.85 Twist Rate with Rifle-Length Gas and 5R Rifling.
U.S. made and manufactured to MIL-SPEC specifications exceeding the ISO-9002 Quality Standard. Provided with a Limited Lifetime Manufacturer Warranty against manufacturers defects.
- Brand: Sanders Armory
- Barrel Caliber: Match Grade 6.5 Grendel II
- Barrel Length: 20 Inch
- Twist Rate: 1:7.85 Twist
- Rifling Process: 5R Button Rifled
- Barrel Prep: Hand Lapped
- Barrel Concentricity held to .002
- Rifling Test: Air Gauged
- Material: 416R Stainless Steel
- Finish: Polished Stainless Steel
- Barrel Interior Finish: Polished Stainless Steel
- Profile: Tapered
- Gas System Length: Rifle-length Gas Tube
- Seat Diameter Gas Block: .750 Gas Block
- Gas Block Dimple: Yes
- Crown Thread Pattern: 5/8 X 24 Thread Pitch
- Barrel Crown: Single Point Cut Polished 11-degree Target Crown
- Barrel Extension: M4 Nitride Coated
- Feed Ramps: M4 cut barrel extension
- Weight: 2 lbs 5oz.
What is 5R Rifling?
Retired Army man Barrett “Boots” Obermeyer developed 5R rifling as a gunsmith in his family’s store and holds a High Master Classification in both high-power rifle disciplines. He is a Distinguished Rifleman who has won numerous shooting awards at both state and national levels. The best definition comes from “Boots” himself …
“5R is the form of rifling I developed for use in most target barrels and many sporting barrels,” he explained. “These barrels have five grooves, and the lands have angular sides. I have observed that bullet jackets will deform such that they remain closer to the R-form lands than they will to the sharp-edged lands present in conventional-style rifling. This reduces powder fouling at the corner of the grooves. The land’s angled form also helps reduce jacket failures in quick-twist barrels.”
The diagram above of rifling profiles shows the difference between traditional rifling (top) and 5R rifling (bottom). Note that the edges of 5R are not square (they don’t cut into bullet jackets as much) and that with 5R, the lands are opposite grooves, while with traditional rifling, lands are opposite lands, and grooves are opposite grooves.
NO shipping to the District of Columbia (Washington, D.C.); Massachusetts; Connecticut; Chicago; Cook County, Deerfield, Highland Park or Aurora Illinois; New Jersey; New York; Puerto Rico; Hawaii; or Canada. NO international shipping must be within the 48 Contiguous United States. NO APO/PPO/FPOs.