AR-15 18" Heavy Barrel, 6.5 Grendel Type 2, 1:8 5R, Straight Fluted, Stainless

This is a premium grade 18" Stainless steel AR-15 Heavy Barrel from a highly respected U.S. contractor/barrel manufacturer.These high-quality barrels are renowned for their deep, crisp, and consistent rifling and extreme accuracy.

1 in 8 5R twist, straight fluted, gas port drilled and set up for mid length gas system and threaded for any standard AR-15 compensator. .750 gas block size and .070 gas port diameter

Barrel Extension in the rear with feed ramps ready to install into any standard AR receiver.Barrel is chambered as 6.5 Grendel Type 2. 1 in 8 twist rate performs well with both heavy and light grain bullets

Made of 416 Gun Quality Stainless Steel for our Stainless Steel, these barrels are manufactured on modern CNC equipment to completely machine the barrel. We drill, ream, rifle, turn, chamber ream, pin the Barrel Extension, drill the gas hole, and mill the flutes, all on late model CNC Equipment. The Barrels are manufactured under the ISO 9002 Quality System, and barrel goes through a Final Inspection before shipping.

What is 5R Rifling

Conventional rifling uses either 6 or 4 symmetrical lands and grooves on the bullet. Each of the lands (the raised portion of the rifling) are directly opposite one another. Likewise the grooves are opposite of one another. 5R rifling improves upon this by using 5 lands and grooves over the even numbers which puts lands opposite of grooves. Further, the transition from the top of the land to the groove is sloped.

5R reduces projectile deformation as it passes through the bore during the firing sequence. By placing the lands opposite of the grooves, the bullets are no longer squeezed on opposite sides ensuring the projectile stays uniform instead of squeezing material into the grooves. More uniform projectile means better accuracy. Secondly, by sloping the transition to the groove, the barrels become much easier to clean. In a conventionally rifled platform, these corners become depositories for lead and superheated materials left after shooting. Cleaning supplies have a hard time reaching these corners as they are incredibly small. By sloping it, cleaning supplies are easily able to get to the deposits.